Combo with "BIO 2160-Test Mastering A&P Ch. 11" and 25 others

Nerve impulses

A brief reversal of membrane potential with a total amplitude of 100 mV They do not decrease in strength over distance They are the principal means of neural communication Occur only in the axon of a neuron Nerve Impulse Once initiated it has the same physiology as an Action Potential in a muscle cell. Initiation is by voltage gated Na channels on the membrane of the axon hillock and results from the summation of graded potentials. Threshold - a critical level of depolarization (-55 to -50 mV) At threshold, depolarization becomes self-generating

Of what do we think an engram consists?

A permanent change in the synapses of a specific circuit of neurons that facilitates impulse transmission at those synapses.

What happens wheen the limbic system operates without the influence of other parts of the cerebral cortex?

Normal emotional expression is impaired. (ex: abnormal, uncontrollable fits of rage)

lumbar puncture

A procedure used to remove cerebrospinal fluid from the spinal canal & it's done between L3 & L4 or L4 & L

Describe Depolarization

A reduction in membrane potential (toward zero) Inside of the membrane becomes less negative than the resting potential Increases the probability of producing a nerve impulse

A reflex arc always includes a(n) __________. efferent axon sensory receptor afferent axon A reflex arc always includes all of these structures.

A reflex arc always includes all of these structures.

temporal lobe

A region of the cerebral cortex responsible for hearing and language. Purple area

Motor output

A response to integrated stimuli that activates muscles or glands

Summation of potentials

A single potential cannot induce a nerve impulse at the axon hillock Potentials must summate temporally or spatially to induce an action potential Temporal summation - all potentials are received from the same terminal Spatial summation - postsynaptic neuron is stimulated by a large number of terminals at the same time Both inhibitory (-) and excitatory (+) potentials sum

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane?

A single type of channel will open, permitting simultaneous flow of sodium and potassium.

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A single type of channel will open, permitting simultaneous flow of sodium and potassium. Sodium gates will open first, then close as potassium gates open. Specific potassium gates will open. Specific sodium gates will open.

A single type of channel will open, permitting simultaneous flow of sodium and potassium.

midbrain

A small part of the brain above the pons; it contains grey matter, nerve fibers & reflex centers that move the eyes & head (11)

infundibulum

A stalk that attaches the pituitary gland to the hypothalamus.

Relative Refractory Period

A stronger-than-threshold stimulus can initiate another action potential

What are engrams?

A structural traces, or specific part of the brain, where a long term memory is stored.

Types of plasma ion channels

Passive channels - always open Chemically gated channels - open with binding of a specific neurotransmitter Voltage-gated channels - open and close in response to membrane potential Mechanically gated channels - open and close in response to physical deformation of receptors

trigeminal neuralgia

AKA Tic Douloreux. Lightning-like pain. Electric shocks caused by compression of trigeminal nerve

Describe information transfer in a chemical synapse

AP arrives at axon terminal of the presynaptic neuron and opens voltage-gated Ca2+ channels Synaptotagmin protein binds Ca2+ and promotes fusion of synaptic vesicles with axon membrane Exocytosis of neurotransmitter occurs Neurotransmitter diffuses and binds to receptors (often chemically gated ion channels) on the postsynaptic neuron Ion channels are opened, causing an excitatory or inhibitory event (graded potential) See p. 409 in textbook

transmitter

AS A RESULT OF PRESYNAPTIC FACILITATION: An action potential in the presynaptic terminal leads to a greater amount of Ca2+ influx, and therefore more ______ is released

transmitter

AS A RESULT OF PRESYNAPTIC INHIBITION: Fewer Ca2+ channels are opened with a subsequent action potential in Presynaptic cell and therefore the Ca2+ influx will be reduced. Less Ca2+ influx leads to less _______ release and a smaller EPSP.

The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction?

Acetylcholine is released by axon terminals of the motor neuron.

What enzyme rapidly decomposes the acetylcholine that cholinergic fibers release

Acetylcholinesterase

What is the stimulus in the withdrawal reflex

Activated skin receptors

Neurotransmitters: Novel Messengers Nitric oxide (NO)

Activates the intracellular receptor guanylyl cyclase Is involved in learning and memory Carbon monoxide (CO) is a main regulator of cGMP in the brain May explain narcotic effects of Nitrogen under pressure and CO excess

What is the response in the withdrawal reflex

Activation of muscles

Much of the norepinephrine released from adrenergic fibers is released from the synapse by what

Active transport

The axoplasm of the axon contains which of the following? neurofibrils vesicles neurotubules mitochondria All of the answers are correct.

All of the answers are correct.

The effect that a neurotransmitter has on the postsynaptic membrane depends on the characteristics of the receptors. the nature of the neurotransmitter. the quantity of neurotransmitters released. the frequency of neurotransmitter release. All of the answers are correct.

All of the answers are correct.

The efferent division of the peripheral nervous system innervates: heart muscle cells skeletal muscle cells smooth muscle cells glandular cells All of the answers are correct.

All of the answers are correct.

The function of the astrocytes in the CNS includes which of the following? adjusting the composition of the interstitial fluid guiding neuron development maintaining the blood-brain barrier repairing damaged neural tissue All of the answers are correct.

All of the answers are correct.

Which of the following is a recognized class of opioid neuromodulators? dynorphins endomorphins enkephalins endorphins All of the answers are correct.

All of the answers are correct.

Which of the following is true regarding an epidural block? It can provide sensory and motor anesthesia, depending on the anesthetic selected. It affects only the spinal nerves in the immediate area of the injection. It can provide mainly sensory anesthesia, depending on the anesthetic selected. It is commonly used as a method of pain control during labor and delivery. All of the answers are correct.

All of the answers are correct.

A synaptic cleft, or synaptic gap, can be found between a neuron and ______. another neuron. a gland. a muscle cell.

All of them

Ridges or convolutions, separated by grooves that mark the cerebrums surface

Gyri

at once

During spatial summation many presynaptic cells are sending signals. Postsynaptic cell has to sum all the info ___ ___.

cancel

During spatial summation of EPSPs and IPSPs changes in membrane potential can _____ each other out.

depolarizing

During stimulatory effect neurotransmitters act on receptors on postsynaptic cell and have the effect of ______ the postsynaptic cell.

last

During temporal summation the action potentials fire close together, the _____ action potential fired is what causes the depolarization.

open

During the depolarizing phase, Na+ channels ____.

inactivating, k+

During the repolarizing phase, the Na+ channels are _____, and the ___ channels open.

leakage

During the resting state, ALL gated Na+ and K+ channels are closed. Only the ____ channels are opened, maintaining resting membrane potential.

no

During the resting state, ___ ions move through voltage gated channels.

An example of the brain modifying reflex patterns is _________. postponing emptying a full urinary bladder holding your breath deliberately walking on hot coals All of these are examples of the brain modifying reflex patterns.

All of these are examples of the brain modifying reflex patterns.

wernicke's area

An area of the brain's left hemisphere that is involved in language comprehension.

Muktiple Sclerosis

An autoimmune disease that mainly affects young adults Symptoms: visual disturbances, weakness, loss of muscular control, and urinary incontinence Immune cells attack and damage the neurilemma and myelin sheath Shunting and short-circuiting of nerve impulses occurs

cardio

An example of electrical synapse is between ______-myocytes.

What conditions will increase the diffusion of molecules, such as neurotransmitters?

An increase in the amount of neurotransmitter exocytized by the presynaptic axon.

List types of neuroglia and in what systems they are found

Astrocytes (CNS) Microglia (CNS) Ependymal cells (CNS) Oligodendrocytes (CNS) Satellite cells (PNS) Schwann cells (PNS)

receptor proteins; postsynaptic

At a chemical synapse, ____________ are found only in the plasma membrane of the ____________ cell. A) neurotransmitters; postsynaptic B) receptor proteins; postsynaptic C) neurotransmitters; presynaptic D) receptor proteins; presynaptic

What two parts typically make up a chemical synapse?

Axon terminal of the presynaptic neuron, which contains synaptic vesicles Receptor region on the postsynaptic neuron Gap between the two is the SYNAPTIC CLEFT

Synaptic cleft

Axonal terminals are separated from the next neuron by a gap called the ______

neurotransmitters

Axonal terminals contain vesicles with ______

Which of the following is not a chemical class of neurotransmitters? A) acetycholine B) amino acid C) biogenic amine D) ATP and other purines E) nucleic acid

E

Which of the following is not a function of astrocytes? A) support and brace neurons B) anchor neurons to blood vessels C) guide the migration of young neurons, synapse formation, and helping to determine capillary permeability D) control the chemical environment around neurons E) provide the defense for the CNS

E

Which of the following correctly describes a graded potential? A) long distance signaling B) amplitude of various sizes C) voltage stimulus to initiate D) voltage regulated repolarization

B

Which of the following describes the excitatory postsynaptic potential? A) short distance hyperpolarization B) short distance depolarization C) opens K+ or Cl- channels D) moves membrane potential away from threshold

B

Which of the following describes the nervous system integrative function? A) senses changes in the environment B) analyzes sensory information, stores information, makes decisions C) responds to stimuli by gland secretion or muscle contraction

B

Which of the following is false or incorrect? A) An excitatory postsynaptic potential occurs if the excitatory effect is greater than the inhibitory effect but less than threshold. B) A nerve impulse occurs if the excitatory and inhibitory effects are equal. C) An inhibitory postsynaptic potential occurs if the inhibitory effect is greater than the excitatory, causing hyperpolarization of the membrane.

B

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone? A) acetylcholine B) endorphin C) serotonin D) nitric oxide

B

putamen *** not on test #11

Basal ganglia associated with sensorimotor and movement *** not on test #11

Often called the basal ganglia..masses of gray matter deep within the cerebral hemispheres

Basal nuclei

The two main function so the spinal card are

Center for spinal reflexes & a conduit for impulses to and from the brain

The gray commissure surrounds the

Central canal

Thin layer of gray matter on the surface of the white matter in the cerebellum is known as the

Cerebellar cortex

The cerebellum communicates with other parts of the CNS by means of 3 pairs of nerve tracts called

Cerebellar peduncles

Large mass of tissue inferior to the occipital loves of the cerebrum & posterior to the pons & the medulla oblongata is the

Cerebellum

Narrow canal that passes lengthwise through the brainstem and connects the 4th ventricle to the 3rd is called

Cerebral aqueduct

Spaces and brain regions produced by the mesencephalon

Cerebral aqueduct; midbrain

Outermost portion of the cerebrum is covered by a thin layer of gray matter which houses abt 75% of all the neuron cell bodies in the nervous system is called the

Cerebral cortex

2 prominent bundles of nerve fibers on the underside of the midbrain comprise the..which include the corticospinal tracts & are the main motor pathways btwn the cerebrum & the lower parts of the nervous system

Cerebral peduncles

Largest part of the mature brain & has 2 hemispheres

Cerebrum

occipital lobe

Cerebrum Lobe responsible for vision (yellow area)

Thickening of the spinal cord in the neck region that supplies nerves to the upper limbs is called what

Cervical enlargement

Plexus of nerves to the muscles & skin of the neck formed btwn C1-C4

Cervical plexus

Neurotransmitters

Chemicals used for neuronal communication with the body and the brain 50 different neurotransmitters have been identified Classified chemically and functionall

Preganglionic neurons of the sympathetic & parasympathetic division all secrete acetylcholine & are called

Cholinergic

__________ receptors on skeletal muscle cells are of the __________ type.

Cholinergic; nicotinic

Tiny, reddish cauliflower-like masses of specialized capillaries from the pia mater that secrete CSF are called

Choroid plexuses

Chemical transmitters

Classified into chemical families Acetylcholine (ACh) Biogenic amines Amino acids Peptides Novel messengers: ATP and dissolved gases NO and CO

5) Bipolar neurons are commonly ________. A) motor neurons B) called neuroglial cells C) found in ganglia D) found in the retina of the eye

D

Strong stimuli cause the amplitude of action potentials generated to increase.

False

Strong stimuli cause the amplitude of action potentials generated to increase. T or F

False

The ANS stimulates smooth muscles, skeletal muscles and glands, whereas the somatic nervous system innervates skeletal muscles only T/F

False

The all-or-none phenomenon as applied to nerve conduction states that the whoel nerve cell must be stimulated for conduction to take place. T/F

False

The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place.

False

The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. T or F

False

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary.

False

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary. T or F

False

The nodes of Ranvier are found only on myelinated, peripheral neuron processes.

False

The nodes of Ranvier are found only on myelinated, peripheral neuron processes. T or F

False

The sodium-potassium pump ejects two Na+ from the cell and then transports three K+ back into the cell in order to maintain the concentration gradients for sodium and potassium.

False

The sympathetic and parasympathetic divisions of the ANS have the same effect on most body organ systems. T/F

False

Unmyelinated fibers conduct impulses faster than myelinated fibers.

False

The sodium-potassium pump ejects two Na from the cell and then transports three K back into the cell in order to stabilize the resting membrane potential.

False The sodium-potassium pump ejects three Na from the cell and then transports two K back into the cell in order to stabilize the resting membrane potential

Separates the R&L cerebellar hemispheres

Falx cerebelli

Extends down into the longitudinal fissure & separates the R&L cerebral hemispheres

Falx cerebri

Layer of dura matter that separates the hemispheres of the cerebrum

Falx cerebri

The 3 major ascending tracts which conduct sensory impulses to the brain are

Fasciculus gracilis & cuneatus, lateral & anterior spinothalmic tract, posterior & anterior spinocerebellar tracts

Supply's motor impulses to muscles of the anterior thighs & receives sensory impulses from the skin of the thighs & legs

Femoral nerves

Thin cord of connective tissue that originates from the conus medullaris, descending to the upper surface of the coccyx is called what

Filum terminale

Deep grooves are called

Fissures

Interneurons (association neurons)

Found in the neural pathways in the central nervous system Connect sensory and motor neurons

corpora quadrigemina *** not on test #13

Four rounded elevations; centers for visual & auditory reflexes *** not on test #13

Neural Integration: Neuronal Pools

Functional groups of neurons that: Integrate incoming information Forward the processed information to its appropriate destination

Ependymal cells ________.

Help to circulate the cerebrospinal fluid

How do action potential propagation speeds compare in myelinated and unmyelinated axons?

Propagation is faster in myelinated axons.

ow do action potential propagation speeds in myelinated and unmyelinated axons compare?

Propagation is faster in myelinated axons.

3 major cavities of embryonic brain development..(forebrain, midbrain & hindbrain)

Prosencephalon, mesencephalon & rhombensephalon

General functions of Neuroglia

Provide a supportive scaffolding for neurons Segregate and insulate neurons Guide young neurons to the proper connections Promote health and growth

withdrawal reflex

Pulling body part away from source of stimulation, Usually initiated by pain; a protective response reflex

Which of the following is NOT a difference between graded potentials and action potentials?

Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.

Chemical synapses

Specialized for the release and reception of neurotransmitters Typically composed of two parts: Axonal terminal of the presynaptic neuron, which contains synaptic vesicles filled with neurotransmitters Receptor region on the postsynaptic neuron

The preganglionic fibers lead outward on cranial & sacral nerves to ganglia near or in various organs known as

Terminal ganglia

voltage na+

The TYPES OF CHANNELS for an action potential are restricted to the _______ channel specifically.

ions

The exchange of _____ initiates an action potential in the neuron

In a myelinated axon, how do the nodes of Ranvier differ from other segments of the same axon? The nodes are longer segments of the axon. The nodes are wrapped in myelin. The nodes are less numerous. The nodes are more permeable to ions.

The nodes are more permeable to ions.

What occurred in the presence of tetrodotoxin?

The number of action potentials decreased, and an action potential was always seen at R1

What is the function of the myelin sheath?

The myelin sheath increases the speed of action potential conduction from the initial segment to the axon terminals.

Which of the following best describes the concept of integration?

The nervous system processes and interprets sensory input and decides what should be done at each moment.

common

The neurotransmitter acetycholine is the most _____ in the body.

hich of the following occurred in the presence of tetrodotoxin?

The number of action potentials decreased.

Neuroglia

Support and protect neurons

Describe the structure and function of Satellite cells

Surround (wrap around) neuron cell BODIES in the PNS Similar to astrocytes in CNA - serve communication function

Describe the structure and function of Schwann cells (neurolemmocytes)

Surround peripheral nerve fibers and form myelin sheaths (whole cell, not just processes) Cytoplasm squeezed out is called neurilemma Vital to regeneration of damaged peripheral nerve fibers

Fight or flight is what division of the autonomic NS

Sympathetic

2 divisions of the autonomic NS

Sympathetic & parasympathetic

Ganglia located in chains along the sides of the vertebral column are known as

Sympathetic chain ganglia

The sympathetic chain ganglia and their fibers compose the

Sympathetic trunks

Two functional subdivisions of Autonomic (involuntary) nervous system (ANS)

Sympathetic: FIGHT/FLIGHT Parasympathetic: REST/DIGEST

What are chemical synapses?

Synapses specialized for the release and reception of neurotransmitters

Calcium entry into the axon terminal triggers which of the following events?

Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine.

ligand gated sodium channels open and sodium diffuses in

THE SYNAPSE: Acetylcholine has which effect on the post-synaptic neuron? A) Ligand gated calcium channels open and calcium diffuses in. B) Ligand gated sodium channels open and sodium diffuses in. C) Terminal vessels migrate to the plasma membrane. D) Voltage gated calcium ion channels open and calcium diffuses in. E) Voltage gated sodium ion channels open and sodium diffuses in.

false

THE SYNAPSE: Acetylcholine is actively transported from the pre-synaptic membrane to the post - synaptic membrane. A) True B) False

calcium ions to diffuse into the cell

THE SYNAPSE: An action potential arriving at the presynaptic terminal causes... A) sodium ions to diffuse into the cell. B) sodium ions to diffuse out of the cell. C) calcium ions to diffuse into the cell. D) acetylcholine to diffuse into the cell. E) ligand-gated sodium channels to open.

synaptic vesicles migrate to the plasma membrane and release acetylcholine

THE SYNAPSE: As a result of calcium ions diffusing into the presynaptic cell... A) synaptic vesicles migrate to the plasma membrane and release acetylcholine. B) acetylcholine is actively transported from the pre-synaptic neuron. C) acetylcholine is actively transported to the post synaptic neuron. D) ligand-gated sodium channels open. E) sodium ions diffuse into the cell.

true

THE SYNAPSE: If the post-synaptic membrane potential reaches threshold level, an action potential will be produced. A) True B) False

filum terminale

Tapering end of spinal cord, distal to the conus medullaris

Anterior portion of the prosencephalon

Telencephalon

What is another name for the terminal branches of an Axon?

Telodendria

When one or more presynaptic neurons fire in rapid order it produces a much greater depolarization of the postsynaptic membrane than would result from a single EPSP; this event is called ________ summation.

Temp-oral

What is the response in the patellar tendon reflex

Tension in the quadriceps femoris muscle group

Separates the occipital lobes of the cerebellum and the cerebrum

Tentorium cerebelli

analgesia

The relief of pain without loss of consciousness.

What effect did increasing the extracellular potassium have on the resting membrane potential?

The resting membrane potential became less negative.

In their resting state, all body cells exhibit a resting membrane potential ranging from -50 to about +50 millivolts.

The resting membrane potential is maintained by solely by passive transport processes.

Hypothetically, what would be the most immediate effect of doubling the number of Na+ leakage channels in the plasma membrane?

The resting membrane potential would become less negative (more positive).

Suppose a drug is developed that blocks K+ leakage channels. The drug prevents ions from passing through those channels. If this drug was applied to a neuron, what would be the most immediate effect on that neuron?

The resting membrane potential would become less negative (more positive).

endorphins

The sensory neuron for pain accepts presynaptic inhibition from enkephalins, more commonly called ______.

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. T or F

True

Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers.

True

Large-diameter nerve fibers conduct impulses much faster than small-diameter fibers. T or F

True

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte.

True

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. T or F

True

Neurons and nerve cells are different names for the same thing.

True

Neurons are also called nerve cells.

True

Neurons in the CNS are organized into functional groups.

True

Neurons in the CNS are organized into functional groups. T or F

True

Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP).

True

Reflexes are rapid, automatic responses to stimuli.

True

Reflexes are rapid, automatic responses to stimuli. T or F

True

Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor.

True

Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor. T or F

True

The action potential is caused by permeability changes in the plasma membrane.

True

The action potential is caused by permeability changes in the plasma membrane. T/F

True

The action potential is caused by permeability changes in the plasma membrane. T or F

True

The oligodendrocytes can myelinate serveral axons T/F

True

The oligodendrocytes can myelinate several axons.

True

The overlapping functions of the nervous system are sensory input, integration, and motor output T/F

True

The overlapping functions of the nervous system are sensory input, integration, and motor output.

True

The overlapping functions of the nervous system are sensory input, integration, and motor output. T or F

True

The sympathetic division is also called the "thoracolumbar division" of the autonomic nervous system T/F

True

Through direct neural stimulation, the sympathetic division promotes many metabolic effects via hormone release. T/F

True

Unipolar neurons have axons structurally divided into peripheral and central processes.

True

Unipolar neurons have axons structurally divided into peripheral and central processes. T or F

True

Temporal Summation

Two action potentials arrive in close succession at the presynaptic membrane

Functional Classification of Neurotransmitters

Two classifications: excitatory and inhibitory Excitatory neurotransmitters cause depolarizations Inhibitory cause hyperpolarizations Some have both excitatory and inhibitory effects Determined by the receptor type of the postsynaptic neuron Example: acetylcholine Excitatory at neuromuscular junctions Inhibitory in cardiac muscle

temporal summation

Two excitatory stimuli close in time cause EPSPs that add together.

spatial summation

Two simultaneous stimuli at different locations cause ESPSs that add together.

no summation

Two stimuli seperated in time cause EPSPs that do not add together.

Which of these axons will conduct an action potential most quickly? Type A fiber Type B fiber Type C fiber All fibers have the same propagation speed.

Type A fiber

Compared to type A axons, type C axons are __________. slower propagating unmyelinated smaller diameter Type C axons have all of these characteristics.

Type C axons have all of these characteristics.

The plasma membrane is much more permeable to K+ than to Na+. Why?

There are many more K+ leak channels than Na+ leak channels in the plasma membrane.

presynaptic, cleft, postsynaptic

There are three critical components for a chemical synapse: -_____ axon terminal that releases neurotransmitters -synaptic _____ -________ membrane receptors

Which of the following is NOT a characteristic of peroxisomes?

They contain powerful enzymes called acid hydrolases.

Which of the following is not true of graded potentials?

They increase amplitude as they move away from the stimulus point

Which of the following is not true of graded potentials?

They increase amplitude as they move away from the stimulus point.

Which of the following is not true of graded potentials? They can form on receptor endings. They increase amplitude as they move away from the stimulus point. They can be called postsynaptic potentials. They are short-lived.

They increase amplitude as they move away from the stimulus point.

Which of the following is NOT true of chemical synapses?

They transmit nerve impulses directly from one neuron to another.

Describe Unmyelinated Axons

Thin nerve fibers are unmyelinated One Schwann cell may incompletely enclose 15 or more unmyelinated axons

dentate nucleus *** not on test #16

This is the largest and most lateral of the deep cerebellar nucleus; associated with hand control, maintain posture & coordination; *** not on test #16

During the hyperpolarization phase of the action potential, voltage eventually returns to the resting membrane potential. What processes are primarily responsible for this return to the resting membrane potential?

Voltage-gated K+ channels close. K+ and Na+ diffuse through leakage channels.

What opens first in response to a threshold stimulus?

Voltage-gated Na+ channels

What is the first change to occur in response to a threshold stimulus?

Voltage-gated Na+ channels change shape, and their activation gates open.

Following repolarization, the neuron may become slightly hyperpolarized before it re-establishes its resting membrane potential. Hyperpolarization is due to a difference between how the voltage-gated Na+ and K+ channels work. What is this difference? Voltage-gated Na+ channels stop the flow of Na+ relatively quickly, while voltage-gated K+ channels are slow to close, resulting in the overshoot. Voltage-gated K+ channels possess an inactivation gate that keeps them closed until repolarization is almost complete. Voltage-gated Na+ channels are responsible for depolarization, while voltage-gated K+ channels return K+ to their original location. Voltage-gated Na+ channels can open much faster than voltage-gated K+ channels.

Voltage-gated Na+ channels stop the flow of Na+ relatively quickly, while voltage-gated K+ channels are slow to close, resulting in the overshoot.

During an action potential, after the membrane potential reaches +30 mV, which event(s) primarily affect(s) the membrane potential?

Voltage-gated sodium channels begin to inactivate (close) and voltage-gated potassium channels begin to open.

Deteriorating changes in the distal segment of an axon as a result of a break between it and the soma is called ________ degeneration. Wallerian central neural conduction peripheral

Wallerian

presynaptic, postsynaptic, vesicle

What is A? What is B? What is C? (NOTE-- there are lots of C's, which tells you that A is, infact, A.)

chemical

What is the most common synapse to occur in the body?

enkephalins, endorphins

What two neuropeptides are common in use of analgesia?

larger

What type of diameter makes an action potential faster?

electrical

What type of synapse: Neurotransmission is mediated via conduction of action potentials directly between adjacent cells that are in contact with each other (no synaptic cleft).

depolarization

What us the ONLY phase of generation of action potential that the voltage sensitive, or activation gate is opened?

going in

When BOTH gates are open--- Na+ is ___ ___to the cell.

open, open

When a threshold depolarization occurs; The activation gate will be ____ , and the inactivation gate will be ____.

activation, inactivation

When at rest; The ____ gate is closed, and the ____ is opened.

refractory

When the insensitive gate is closed, but the sensitive gate is opened; it is said that the cell is in a ____ period.

na+

When we say "All or none", we are refering to the fact that the same number of ____ ions will enter a cell due to the activity of both the activation and inactivation gates.

microglia

Which glial cells behave much like certain leukocytes? A) microglia B) ependymal cells C) oligodendrocytes D) satellite cells

neurolemmocytes

Which glial cells participate in the repair of damaged nerves? A) satellite and ependymal cells B) neurolemmocytes C) oligodendrocytes D) astrocytes and microglia

ans and sns

Which nervous system divisions or components contain no afferent neurons? A) somatic and visceral sensory B) CNS and PNS C) PNS and ANS D) ANS and SNS

Types Of glial cells

Glial cells of the CNS are of 4 types Astrocytes - most numerous, involved in care and feeding of neurons Microglia - specialized phagocytes Ependymal cells - ciliated cells lining CNS cavities that secrete CSF Oligodendrocytes - produce myelin sheaths in the CNS Glial cells of the PNS are of 2 types Satellite cells - surround PNS neuron cell bodies, function unknown Schwann cells - produce myelin sheaths in the PNS

Cranial nerves IX..muscles in pharynx..blood pressure in carotid sinus..1/3 of tongue..mixed

Glossopharyngeal

excitatory

Glutamate is _____ in the CNS.

inhibitory

Glycine is ______ in the CNS.

k+

Hyperpolarization is caused by _____ continuing to leave the cell.

Cranial nerves XII..muscles of the tongue..primarily motor

Hypoglossal

Region within the diencephalon that includes many nuclei and forms the lower walls & floor of the 3rd ventricle..regulates a variety of visceral activities important in homeostasis & also regulates some of the endocrine system

Hypothalamus

What is the difference between white and gray matter?

White matter: Dense collections of myelinated fibers Gray matter: Mostly neuron cell bodies and unmyelinated fibers

Preganglionic fibers leave the spinal nerves through branches called

White rami

Myelin sheath

Whitish, fatty (protein-lipoid), segmented sheath around most long axons It functions to: Protect the axon Electrically insulate fibers from one another Increase the speed of nerve impulse transmission

What are the differences in ionic makeup between ICF and ECF in a "resting" neuron?

ICF has lower concentration of Na+ and Cl- than ECF ICF has higher concentration of K+ and negatively charged proteins (A-) than ECF

The third ventricle communicates with the 2 lateral ventricles through openings called

Interventricular foramina

Passageway btwn vertebrae to & from the spinal cord is known as the

Intervertebral foramen

Neurotransmitters: Novel Messengers ATP

Is found in both the CNS and PNS Produces excitatory or inhibitory responses depending on receptor type Induces Ca2+ wave propagation in astrocytes Provokes pain sensation

Nerve cell body(soma)

Is the major biosynthetic center hence has well-developed Nissl bodies (rough ER) and Golgi Is the focal point for the outgrowth of neuronal processes Contains an axon hillock - cone-shaped area from which axons arise

How would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactivate? It would be much briefer. It would last indefinitely. It would be basically unaffected.

It would last indefinitely.

What type of reflex occur when you touch something painful or potentially damaging

Withdrawal reflex

The electrochemical gradient for potassium ions when the transmembrane potential is at the resting potential (-70 mV) is caused by what?

a chemical gradient going out of the cell and an electrical gradient going into the cell

What type of channel on the postsynaptic membrane binds neurotransmitter?

a chemically gated channel

What is the posterior median sulcus?

a deep groove on the posterior (back) side of the spinal cord.

What is the anterior median fissure?

a deep, wide groove on the anterior (front) side of the spinal cord.

Cardiovascular effects of the sympathetic division include all except _________. a) dilation of the blood vessels serving the skin and digestive viscera b) construction of most blood vessels c) increase of heart rate and force d) dilation of the vessels serving the skeletal muscles

a) dilation of the blood vessels serving the skin and digestive viscera

Which of the following is NOT associated with the parasympathetic division of the autonomic nervous system (ANS)? a) emergency action b) resting c) digesting d) energy conservation

a) emergency action

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? a) acetylcholine b) norepinephrine c) gamma aminobutyric acid d)bcholinesterase

a) acetylcholine

Which neuroglia are the most abundant and versatile of the glial cells? a) astrocytes b) ependymal cells c) oligodendrocytes d) Schwann cells

a) astrocytes

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. a) axon b) dendrite c) Schwann cell d) neurolemma

a) axon

Which of the following is the conducting region of the neuron? a) axon b) dendrites c) terminal boutons d) soma

a) axon

The term central nervous system refers to the ________. a) brain and spinal cord b) brain, spinal cord, and peripheral nerves c) spinal cord and spinal nerves d) autonomic nervous system

a) brain and spinal cord

the term central nervous system refers to the ___________. a) brain and spinal cord b) spinal cord and spinal nerves c) peripheral and spinal nerves d) brain, spinal cord, and peripheral nerves

a) brain and spinal cord

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? a) ependymal cells b) Schwann cells c) oligodendrocytes d) astrocytes

a) ependymal cells

Emotions influence autonomic reactions primarily through integration in the __________ a) hypothalamus b) inferior colliculus c) lateral horn of the spinal cord d) lateral geniculate of the thalamus

a) hypothalamus

Which of the following is responsible for the overall integration of the autonomic nervous system (ANS)? a) hypothalamus b) reticular formation c) frontal lobe of the cerebral cortex d) brain stem

a) hypothalmus

Which of the following types of neurons carries impulses away from the CNS? a) motor b) association c) afferent d) sensory

a) motor

List some characteristics of Neurons (Nerve Cells)

Long-lived (100 years or more) Amitotic (with few exceptions) High metabolic rate: depend on continuous supply of O2 / glucose Plasma membrane functions in: - Electrical signaling - Cell-to-cell interactions during development

Fissure that separates the R&L cerebral hemispheres

Longitudinal fissure

If a drug that inhibits __________ is used, it will cause more acetylcholine to remain in the synaptic cleft to bind to the remaining nicotinic receptors on skeletal muscle cells.

acetylcholinesterase

Which of the following describes the nervous system integrative function?

analyzes sensory information, stores information, makes decisions

reticular formation *** not on test #14

Loosely organized nuclei that extend throughout the brainstem and filter sensory information; arouses the cerebral cortex to new stimulation and keeps the brain alert (even during sleep).**** not on test #14

________ channels open or close in response to physical distortion of the membrane surface. Mechanically-gated Active Voltage-gated Chemically-gated Leak

Mechanically-gated

Describe the threshold stage of action potential

Membrane is depolarized by 15 to 20 mV Na+ permeability increases Na influx exceeds K+ efflux The positive feedback cycle begins

Which statement best describes exocytosis?

Membrane organelles fuse with the membrane and release contents out of the cell.

Define Meninges:

Membranes covering the brain and spinal cord.

Located btwn the bone & soft tissue on the NS, this membrane protects the brain and spinal cord

Meninges

Contains the cerebral aqueduct that connects the 3rd & 4th ventricles

Mesencephalon (midbrain)

Short section of the brainstem between the diencephalon & the pons

Mesencephalon (midbrain)

Anterior portion of the rhombencephalon

Metencephalon

types of glial cells monitor the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?

Microglia

Presynaptic neuron

- conducts impulses toward the synapse

What structural classification describes this neuron?

Multipolar

________ neurons are the most common class in the CNS. Multipolar Unipolar Sensory Anaxonic Bipolar

Multipolar

What are the dentate nuclei and what is their function?

- clusters of neuron cell bodies (one in each cerebellar hemisphere) which are connected by tracts to: the thalamus and motor areas in the cerebrum. - They influence the brain's motor areas and directly affect muscle tone andd movement coordination.

Where are gray and white matter generally found in the cerebellum?

- gray matter found in cortex (outer portion) - white matter predominated interior

What is the function of the Basal Ganglia?

- help regulate voluntary motor functions. - ex: most muscle contractions involved in posture, walking, and other gross or repetitive movements are begun or modified in the basal ganglia.

Describe the Epidural space:

- space between boney coverings and the dura mater. - contains supporting cushion of fat and other connective tissues.

Describe the Subdural space:

- space between dura mater and arachnoid membrane. - contains a little lubricating serous fluid.

Describe the Subarachnoid space:

- space between the arachnoid and pia mater. - contains cerebrospinal fluid (CSF).

What 2 structures does the medulla connect? Of what is the medulla composed?

- spinal cord and the pons. - composed of white matter (tracts) and the reticular formation.

A chemical messenger that does not directly cause ESPSs or IPSPs but does affect the strength of synaptic transmission is a ________.

Neuro-mod-ulator

________ account for roughly half of the volume of the nervous system. Dendrites Efferent fibers Neuroglia Synapses Axons

Neuroglia

cerebral aqueduct

Passageway for CSF between 3rd and 4th ventricle ( 4 )

What is the role of neurotransmitter at a chemical synapse?

Neurotransmitter binds to receptors on the postsynaptic cell membrane and allows ions to diffuse across the membrane.

synaptic delay

Neurotransmitter must be released, diffuse across the synapse, and bind to receptors Synaptic delay - time needed to do this (0.3-5.0 ms) Synaptic delay is the rate-limiting step of neural transmission

Post synaptic potentials

Neurotransmitter receptors mediate changes in membrane potential according to: The amount of neurotransmitter released The amount of time the neurotransmitter is bound to receptors The two types of postsynaptic potentials are: Excitatory postsynaptic potentials Inhibitory postsynaptic potentials

The afferent division of the PNS _____________. controls smooth muscle carries sensory information carries motor commands controls skeletal muscle

carries sensory information

describe motor or efferent neurons

carry impulses away from the CNS to the effector organs (muscles and glands) of the body periphery, multipolar, mostly cell bodies located in CNS

Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?

resting membrane potential

The brain area that regulates activities that control the state of wakefulness or alertness of the cerebral cortex is the ________. limbic system pyramids reticular formation thalamus

reticular formation

The rabies virus travels to the CNS via retrograde axoplasmic transport. subcutaneous connective tissue. blood vessels. cerebrospinal fluid. anterograde axoplasmic transport.

retrograde axoplasmic transport.

what is movement away from the axon terminals called

retrograde movement

Which pattern of neural processing works in a predictable, all-or-nothing manner, where reflexes are rapid and automatic responses to stimuli in which a particular stimulus always causes the same response?

serial processing

Which pattern of neural processing works in a predictable, all-or-nothing manner, where reflexes are rapid and automatic responses to stimuli in which a particular stimulus always causes the same response? oscillative processing parallel processing serial processing reflexive processing

serial processing

Spinocerebellar tracts ________. terminate in the spinal cord give rise to conscious experience of perception carry proprioceptive inputs to the cerebellum are found in the dorsal columns of the spinal cord

carry proprioceptive inputs to the cerebellum

All of the following are structures of the limbic system except the ________. amygdaloid nucleus hippocampus cingulate gyrus caudate nucleus

caudate nucleus

what happens when the impulse reaches the axon terminal

causes neurotransmitters, signalling chemicals stored in vesicles there to be released into the extracellular space

What happens to the spinal cord between L1 and L2 vertebrae?

ceases to be a solid body. Individual nerves continue into Lumbar. Sacral & Coccygeal parts of spine hang loose and look like a horse's tail called the Caudum Equinum.

The dorsal root ganglia mainly contain synapses. cell bodies of motor neurons. axons of motor neurons. cell bodies of sensory neurons. axons of sensory neurons.

cell bodies of sensory neurons.

The dorsal root ganglia consist mainly of __________. axons of multipolar neurons axons of unipolar neurons cell bodies of multipolar neurons cell bodies of unipolar neurons

cell bodies of unipolar neurons

why is the protective role of microglia important

cells of the immune system are denied access to the CNS

The ________ nervous system is composed of the brain and spinal cord. central efferent afferent peripheral autonomic

central

What part of the nervous system performs information processing and integration?

central nervous system

What part of the nervous system performs information processing and integration? somatic nervous system central nervous system parasympathetic nervous system sympathetic nervous system

central nervous system

what are the two parts of the nervous system

central nervous system and peripheral nervous system

The spinal cord is part of the autonomic nervous system. central nervous system. peripheral nervous system. somatic nervous system. afferent nervous system.

central nervous system.

Subdivisions of nervous system

central: spinal cord and brain peripheral: sensory receptors and nerves

Which of these components is usually absent from a neuron? centrioles cell body dendrites axons

centrioles

The arbor vitae refers to ________. the pleatlike convolutions of the cerebellum cerebellar white matter cerebellar gray matter flocculonodular nodes

cerebellar white matter

Which of the following regions of the brain provides the precise timing and appropriate patterns of skeletal muscle contraction for the smooth, coordinated movements and agility that are needed for our daily living? cerebellum medulla oblongata pons midbrain

cerebellum

Which part of the brain processes inputs received from the cerebral motor cortex, brain stem nuclei, and various sensory receptors, and then uses this information to coordinate somatic motor output so that smooth, well-timed movements occur? cerebellum thalamus pons diencephalon

cerebellum

Which parts of the brain constitute the "emotional brain" known as the limbic system? diencephalic and brain stem structures cerebral and brain stem structures cerebral and diencephalic structures diencephalic and mesencephalic structures

cerebral and diencephalic structures

Which part of the brain is the "executive suite" for all brain activity? diencephalon brain stem cerebellum cerebral cortex

cerebral cortex

White matter (myelinated fibers) is found in all of the following locations except the ________. outer portion of the spinal cord cerebral cortex corpus callosum corticospinal tracts

cerebral cortex

Muscles of the neck and shoulder are innervated by spinal nerves from the ________ region. cervical coccygeal lumbar sacral thoracic

cervical

Which of the following is not a possible drug effect on synaptic function? interfere with neurotransmitter reuptake interfere with neurotransmitter synthesis change the type of receptor found in the postsynaptic membrane prevent neurotransmitter inactivation block neurotransmitter binding to receptors

change the type of receptor found in the

stimuli

changes

Leak channels allow the movement of potassium and sodium ions by what type of membrane transport?

channel-mediated diffusion

Which of the following is NOT a functional classification of neurotransmitters?

chemical

Which type of synapse is most common in the nervous system? electrical processing chemical radiative mechanical

chemical

The electrochemical gradient for sodium ions in a neuron when the transmembrane potential is at the resting potential is caused by what?

chemical and electrical gradients both going into the cell

Which component has a role in the postsynaptic cell during synaptic activity?

chemically gated channels

Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane.

chemically gated; postsynaptic

A postsynaptic neuron will have an Excitatory Postsynaptic Potential (EPSP) when more calcium ions than usual diffuse into the neuron. the neuron is hyperpolarized. chemically-regulated potassium channels are open and potassium is diffusing out of the cell. chemically-regulated sodium channels are open and sodium is diffusing into the cell. more potassium ions than usual diffuse out of the neuron.

chemically-regulated sodium channels are open and sodium is diffusing into the cell.

Which of the following is NOT one of the chemical classes into which neurotransmitters fall?

chlorides

Which of the following is NOT one of the chemical classes into which neurotransmitters fall? amino acids gases and lipids chlorides peptides

chlorides

The receptors on effectors for parasympathetic postganglinic axons are categorized as __________, while the receptors on effectors for sympathetic postganglionic axons are __________.

cholinergic; adrenergic

Which type of white matter fiber tract connects the two cerebral hemispheres? internal capsules commissures association fibers projection fibers

commissures

Which of the following is the mildest consequence of traumatic brain injury? concussion swelling hemorrhage contusion

concussion

Axon

conduct impulses away from the cell body

Dendrites

conduct impulses toward the cell body

Functions of astrocytes include all of the following, except guiding neuron development. maintaining the blood-brain barrier. responding to neural tissue damage. conducting action potentials. forming a three-dimensional framework for the CNS.

conducting action potentials.

what does the axon do

conducting region, generates nerve impulses and transmits them, typically away from the cell body along the plasma membrane or axolemma

We describe the regeneration of the action potential down the membrane of the axon of the neuron as _______.

conduction or propagation

massa intermedia

connects the two halves of the thalamus together

Integral membrane proteins that connect electrical synapses are called desmosomes. synapsins. sodium channels. receptors. connexons.

connexons.

what does the afferent division do

consists of nerve fibres (axons) that convey impulses to the central nervous system from sensory receptors

What type of conduction takes place in unmyelinated axons?

continuous conduction

Which of the following is a characteristic of a coma but is NOT a characteristic of sleep? absence of brain waves ("flat EEG") irreversible brain damage continuously reduced mitochondrial activity in brain neurons All of the listed responses are correct.

continuously reduced mitochondrial activity in brain neurons

What is the function of the Accessory nerve?

control muscles of back & neck.

What is the function of the Abductens nerve?

control muscles that abduct the eyes.

What is the function of the Hypoglossal nerve?

control muscles that move the tongue.

What is the function of the Oculomotor nerve?

control muscles that: control eye movement, opening of iris, and focus the lenses.

What is the function of the Trochlear nerve?

control some eye movement.

pons

controls the rate and depth of breathing; relays nerve impulses between medulla oblongata & cerebellum

medulla oblongata

controls vital & nonvital reflexes: breathing, heart rate, vomiting, salivations, coughing, and sneezing; located at lowest portion of brainstem

K out of cell

depolarization, less gradient

An action potential is self-regenerating because __________.

depolarizing currents established by the influx of Na+ flow down the axon and trigger an action potential at the next segment

The region of the body surface monitored by a pair of spinal nerves is known as a(n) __________. segment input domain dermatome dermal band

dermatome

What is the role of acetylcholinesterase?

destroy ACh a brief period after its release by the axon endings

What type of membrane transport causes the depolarization phase of the action potential in neurons?

diffusion

Which of the following is not a function of the nervous system? integrate sensory information control peripheral effectors direct long-term functions, such as growth sense the internal and external environments coordinate voluntary and involuntary activities

direct long-term functions, such as growth

The synapse more common in embryonic nervous tissue than in adults is the ________.

electrical synapse

Where are muscarinic cholinergic receptors found?

effector organs of the parasympathetic nervous system

Binding of the neurotransmitter to its receptor causes the membrane to __________.

either depolarize or hyperpolarize

Myasthenia gravis directly causes a decrease in the __________ in skeletal muscle cells.

end-plate potential

The reason that the skeletal muscle __________ get smaller after repetitive stimulation is due to acetylcholine being ineffectively used as the somatic motor neuron continues to fire action potentials.

end-plate potentials

Sensory receptors

endings of neurons or cells that detect senses

The outermost connective-tissue covering of nerves is the perineurium. endomysium. epineurium. endoneurium. epimysium.

epineurium.

Cold sores on the skin of the mouth occur when herpes simplex viruses that are dormant in neural ganglia become active and travel to the skin of the mouth. Which of the following is the mechanism by which these viruses travel from the ganglia (located within the head) to the skin of the mouth?

retrograde transport

what are characteristic of neurons

extreme longevity, amitotic, high metabolic rate

Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____.

facilitated diffusion

The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____.

facilitated diffusion

A flat EEG is a good indication of deep sleep. True False

false

Commissural fibers connect the cerebrum to the diencephalon. True False

false

Meningitis is the most accurate term for inflammation of neurons. True False

false

Nondeclarative memories preserve the circumstances in which they are learned. True False

false

Projection fibers in the brain mainly connect the right and left hemispheres. True False

false

Sorting of sensory information and relaying it to the appropriate cerebral sensory area occurs in the hypothalamus. True False

false

Strong stimuli cause the amplitude of action potentials generated to increase. True False

false

The RAS is comprised of specific pathways primarily in the limbic system. True False

false

The all-or-none phenomenon as applied to nerve conduction states that the whole nerve cell must be stimulated for conduction to take place. True False

false

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary. True False

false

The canal connecting the third and fourth ventricles and running through the midbrain is the foramen of Monro. True False

false

The hypothalamus is the area where afferent impulses from all senses and all parts of the body are sorted out and then relayed to the appropriate area of the sensory cortex. True False

false

The nodes of Ranvier are found only on myelinated, peripheral neuron processes. True False

false

The three basic regions of the cerebrum are the cerebral cortical gray matter, internal white matter, and the superior and inferior colliculi. True False

false

In addition to diffusion, what are two other mechanisms that terminate neurotransmitter activity?

reuptake and degragation

Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing?

reverberating circuit

Which neuron circuit pattern is involved in the control of rhythmic activities such as breathing? diverging circuit parallel after-discharge circuit reverberating circuit converging circuit

reverberating circuit

Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing, and certain motor activities (such as arm swinging when walking)?

reverberating circuits

Compared to nerve action potentials, muscle action potentials do not have __________. greater resting potentials slower propagation faster propagation longer duration

faster propagation

Which of these would you not find in the cerebral cortex? dendrites unmyelinated axons fiber tracts cell bodies

fiber tracts

Processes

fibers that extend from the cell body

The ________ is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament. filum terminale ventral root conus medullaris dorsal root cauda equina

filum terminale

cerebral ventricles

four interconnected cavities that lie in the cerebral hemispheres & brainstem; they are continuous with the central canal of the spinal cord & filled with CSF

What does the central nervous system use to determine the strength of a stimulus?

frequency of action potentials

What does the central nervous system use to determine the strength of a stimulus? type of stimulus receptor frequency of action potentials size of action potentials origin of the stimulus

frequency of action potentials

Which of the following areas of the brain controls voluntary movement of the eyes? primary visual cortex gustatory cortex frontal eye field visual association area

frontal eye field

The central sulcus separates which lobes? frontal from parietal temporal from parietal frontal from temporal parietal from occipital

frontal from parietal

Collections of nerve cell bodies outside the central nervous system are called ________.

ganglia

Collections of nerve cell bodies outside the central nervous system are called ________. nuclei nerves ganglia tracts

ganglia

how are astrocytes connected together

gap junctions

Nodes of Ranvier

gaps in myelin sheath along the axon

what are nodes of ranvier or myelin sheath gaps

gaps in the sheath because the schwann cells along an axon do not touch one another

Sensory input

gathering information, to monitor the changes inside/outside of the body

If EPSPs summate to a sustained value above threshold, then the initial segment will __________. generate both large and frequent action potentials inactivate generate a string of action potentials generate larger than normal action potentials

generate a string of action potentials

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________.

generator potential

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. postsynaptic potential generator potential excitatory potential action potential

generator potential

what do sacral nerves control and how many?

genitals lower digestive tract 5

what do astrocytes do for the blood brain barrier?

gives rise to blood-brain barrier to... 1. limits permeability of number of blood-borne substances 2. define what blood-borne components can enter CNS

Bipolar neurons

have 2 projections coming off of the cells body (1 axon, 1 dendrite) Least common- Found in eye and nose

describe multipolar neurons

have 3 or more processes- one axon and rest dendrites, most common neuron, major neuron type in CNS

Unipolar neurons

have a short single process leaving the cell body

describe unipolar neurons

have a single short process that emerges from the cell body and divides T like into proximal and distal branches, found mainly in PNS, common only in dorsal root ganglia of the spinal cord and sensory ganglia of cranial nerves

In contrast to the internodes of a myelinated axon, the nodes __________.

have lower membrane resistance to ion movement

Myasthenia gravis most commonly affects skeletal muscles of the __________.

head

The six projections from the gray matter seen in cross-sections of the spinal cord are called __________. pyramids flares tracts horns

horns

The outward projections from the central gray matter of the spinal cord are called fibers. wings. tracts. pyramids. horns.

horns.

An inhibitory postsynaptic potential (IPSP) is associated with ________.

hyperpolarization

less K in extracellular

hyperpolarization, steeper gradient

An axon that is more negative than the resting membrane potential is said to be

hyperpolarized

An axon that is more negative than the resting membrane potential is said to be _______.

hyperpolarized

The most promising current therapy for myasthenia gravis is __________.

immune type therapy

Describe the impulse pathway of the Reticular Activating System:

impulses from spinal cord --> reticular formations in brain stem --> thalamus --> all parts of the cerebral cortex (without continual impulses from the reticular formations to cortex, you will be unconscious and cannot be aroused)

where are most neuron cell bodies located

in the CNS, protected by bones of skull and vertebral column

Voltage-gated channels are present on the surface of dendrites. on the soma of neurons. at the motor end plate. along the perikaryon of neurons. in the membrane that covers axons.

in the membrane that covers axons.

Compared to the electrical gradient for sodium at rest, the electrical gradient for potassium at rest is __________.

in the same direction and of the same magnitude.

what do dendrites convey

incoming messages toward cell body usually graded potentials

Which of the following does not occur during a narcoleptic sleep episode? increased heart rate REM sleep increased oxygen use increased gastrointestinal activity

increased gastrointestinal activity

Increase in stimulus intensity

increases the frequency of action potentials

Action potential propagation begins (is first generated at) what region of a neuron?

initial segment

Where do most action potentials originate?

initial segment

In what part of the neuron does the action potential typically initiate?

initial segment of the axon

Which of the following is not a role of the basal nuclei? regulating attention and cognition controlling starting and stopping movements initiating protective reflex actions inhibiting unnecessary or antagonistic movements

initiating protective reflex actions

Which of the following is not a function of the CSF? reduction of brain weight protection from blows initiation of some nerve impulses nourishment of the brain

initiation of some nerve impulses

Reflexes based on synapses formed during development are ________ reflexes. visceral innate somatic vegetative acquired

innate

Which of the following is not a function of the autonomic nervous system?

innervation of skeletal muscle

Which of the following is not a function of the autonomic nervous system? innervation of glands innervation of skeletal muscle innervation of cardiac muscle innervation of smooth muscle of the digestive tract

innervation of skeletal muscle

What component of the reflex arc determines the response to a stimulus?

integration center

What component of the reflex arc determines the response to a stimulus? integration center sensory neuron receptor effecto

integration center

what is meant by integration and does it occur mainly in the CNS or PNS

integration involves processing and interpreting sensory information, making a decision about motor output. primarily occurs in CNS

The most abundant category of neurons is __________. somatic afferents somatic motor interneurons visceral motor

interneurons

which neurons make up over 99% of the neurons of the body

interneurons

functions of the brain

interpret sensation, determine perception, stores memory, reasoning, makes decisions, coordinates muscular movements, regulates visceral activities, determines personality

The time interval between the action potential is called the

interspike interval

Autonomic nervous system

involuntary

what is the ANS also called

involuntary nervous system

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

ion channels in the plasma membrane of the receiving neuron open.

The rate with which an action potential travels along an axon _______.

is called the conduction velocity and is measured in meters/sec

Broca's area ________. is usually found in the right hemisphere serves the recognition of complex objects is considered a motor speech area corresponds to Brodmann's area 8

is considered a motor speech area

Declarative memory ________. is hard to unlearn when learned once usually involves motor skills is best remembered in the doing is the ability to learn specific information

is the ability to learn specific information

why is the somatic nervous system called the voluntary nervous system

it allows us to consciously control our skeletal muscles

Spinal nerves from the sacral region of the cord innervate the ________ muscles. abdominal leg facial intercostal shoulder

leg

Which of the following is used to block pain?

lidocaine

In the presence of lidocaine, the action potential was NOT affected at R1 because

lidocaine was applied downstream of R1

In the presence of lidocaine, the action potential was NOT affected at R1 because _______.

lidocaine was applied downstream of R1

describe interneurons/ association neurons

lie between motor and sensory neurons in neural pathways and shuttle signals through CNS pathways where integration occurs, most confined within CNS, almost all are multipolar

where are ependymal cells found

line central cavities of brain, spinal cord form a permeable barrier between cerebrospinal fluid and tissue fluid

where are oligodendrocytes found

line up along thicker neuron fibres in CNS

diencephalon

located between cerebral hemispheres, superior to the brainstem; surrounds 3rd ventricle & consists of the thalamus, hypothalamus, optic chiasm, and pineal body

hypothalamus

located in diencephalon; helps maintain homeostasis by regulating visceral activities and links nervous to the endocrine system

frontal eye field

located in the motor cortex just above the broca's area that controls voluntary movement of eyes & eye lids

post central gyrus

located in the parietal lobe it interprets sensations on skin

The nodes of Ranvier are _______.

locations on the axon where the myelin sheath is absent

Which fissure separates the cerebral hemispheres? central fissure parieto-occipital fissure lateral fissure longitudinal fissure

longitudinal fissure

what does amitotic mean

lose ability to divide, cannot be replaced if destroyed

Injury to the hypothalamus may result in all of the following except ________. loss of body temperature control pathologic sleep loss of proprioception production of excessive quantities of urine

loss of proprioception

Extensive damage to oligodendrocytes in the CNS could result in loss of sensation and motor control. decreased production of cerebrospinal fluid. a breakdown of the blood-brain barrier. loss of the structural framework of the brain. inability to produce scar tissue a the site of an injury.

loss of sensation and motor control.

Type B nerve fiber

medium-diameter, lightly myelinated. Conduct at 3-15 m/s. Part of ANS

The vital centers for the control of heart rate, respiration, and blood pressure are located in the ________. cerebrum midbrain medulla pons

medulla

Which of the following structures is probably not directly involved in memory? thalamus medulla prefrontal cortex hippocampus

medulla

Which part of the brain stem houses the reflex centers for respiration and cardiovascular functioning? reticular formation pons medulla oblongata midbrain

medulla oblongata

Which of the following is NOT a functional region of a neuron?

medullary region

gyri

rounded ridges located on the surface of the cerebral hemispheres of the brain

Parasympathetic preganglionic cell bodies are located in the brainstem and _____ region of the spinal cord.

sacral

The node-to-node "jumping" regeneration of an action potential along a myelinated axon is called __________.

salatory conduction

what substances are moved in the anterograde direction

mitochondria, cytoskeletal elements, membrane components used to renew the axon plasma membrane and enzymes needed for the synthesis of certain neurotransmitters

What are some examples of molecules and organelles moved along an axon toward its TERMINAL end?

mitochondria, membrane components, enzymes

facial nerve ( VII )

mixed nerve; sensory from taste receptors; motor to muscles of facial expressions, salivary & tear ducts ( J )

A primary active transport process is one in which __________.

molecules move through transport proteins that have been activated by ATP

Which of the following would increase the membrane permeability to K+?

more K+ leakage channels

Which of the following would increase the membrane permeability to K+? more K+ leakage channels more negative membrane potential more Na+ leakage channels a greater concentration gradient for K+

more K+ leakage channels

A suprathreshold stimulus results in _______.

more action potentials

what is the peripheral process

more distal process in unipolar neurons often associated with a sensory receptor

The input for the stretch reflex comes from the __________. gamma motor neuron extrafusal fibers muscle spindle efferent fibers

muscle spindle

Myasthenia gravis is an automimmune disease in which antibodies are produced against nicotinic cholinergic receptors. What would be a direct symptom of this?

muscle weakness and/or dysfunction

what are the effector organs

muscles and glands

The white matter of the spinal cord is mainly unmyelinated axons. Schwann cells. myelinated and unmyelinated axons. neuroglia. nodes of Ranvier.

myelinated and unmyelinated axons.

The white matter of the spinal cord contains ________. myelinated and unmyelinated nerve fibers unmyelinated nerve fibers only soma that have both myelinated and unmyelinated nerve fibers myelinated nerve fibers only

myelinated and unmyelinated nerve fibers

Which of these is absent in the gray matter of the spinal cord? neuroglia unmyelinated axons neuron cell bodies myelinated axons

myelinated axons

White matter

myelinated axons. Nerve tracts propagate actin potentials from one area in the CNS to another

do myelinated or unmyelinated fibres conduct quicker nerve impulses

myelinated conduct rapidly

White matter

myelinated fibers (mainly axons)

The node-to-node "jumping" regeneration of an action potential along a myelinated axon is called __________.

saltatory propagation

what is motor output

nervous system causes a response by activating effector organs- muscles and glands

what is in the PNS

nervous system outside CNS, mainly nerves- spinal nerves, cranial nerves

what is integration

nervous system processes and interprets sensory input and decides what to do at each moment

what is sensory input

nervous system uses millions of sensory receptor to monitor changes occurring both inside and outside body, gathered information is sensory input

The sheath of Schwann is also called the ________.

neurilemma

Which of the following are bundles of neurofilaments that are important in maintaining the shape and integrity of neurons?

neurofibrils

Which of the following are bundles of neurofilaments that are important in maintaining the shape and integrity of neurons? perikaryon axolemma chromatophilic substance neurofibrils

neurofibrils

what is the difference between communcation of neurons and communication of neuroglia?

neuroglia can communicate with many other cells at one time, where neurons has a flow of information or communication along chains of neurons

The basic functional unit of the nervous system is the ________.

neuron

How would a chemical that prevents the opening of voltage-regulated Na+ channels affect the function of a neuron? neuron will only be able to hyperpolarize action potentials will lack a repolarization phase neuron will only be capable of producing graded potentials neuron will depolarize more rapidly neuron will automatically and repeatedly produce graded potentials

neuron will only be capable of producing graded potentials

When pressure is applied to neural tissue, all these effects are possible, except a decrease in blood flow. action potentials are generated spontaneously. a decrease in available oxygen. neurons are triggered to divide. glial cells degenerate.

neurons are triggered to divide.

A molecule that carries information across a synaptic cleft is a

neurotransmitter

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________.

neurotransmitter

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. cholinesterase neurotransmitter ion biogenic amine

neurotransmitter

The same ________ can have different effects depending on the properties of the ________. substrate; receptor receptor; neurotransmitter hormone; neurotransmitter propagation; neurotransmitter neurotransmitter; receptor

neurotransmitter; receptor

are dendrites myelinated

never

Which of these neurotransmitters does not bind to a plasma membrane receptor? GABA nitric oxide serotonin norepinephrine

nitric oxide

Increasing the voltage resulted in

no change to the action potential

Increasing the voltage resulted in which of the following?

no change to the action potential

A single action potential is described as _______.

no graded

When the calcium was removed from the extracellular solution

no neurotransmitter was released

When the calcium was removed from the extracellular solution, _______.

no neurotransmitter was released

what organelles are in the axon

same as in dendrites and cell body but without nissl bodies and a golgi apparatus (Structures involved with protein synthesis and packaging)

Which of the following is a type of glial cell found in the peripheral nervous system? satellite cells oligodendrocytes ependymal cells astrocytes microglia

satellite cells

Which of these types of neuroglia are abundant in peripheral ganglia? microglia oligodendrocytes astrocytes satellite cells

satellite cells

Glial cells that surround the neurons in ganglia are oligodendrocytes. satellite cells. ependymal cells. astrocytes. microglia.

satellite cells.

Neuroglia of PNS

schwann and satellite

how do oligodendrocytes differ from schwann cells

schwann cells only form one segment of a myelin sheath but oligodendrocytes have multiple flat processes that can coil around as many as 60 axons at the same time

myelin sheaths in the PNS are formed by what

schwann cells which indent to receive an axon and then wrap themselves around it in a jelly role fashion, initially lose but gradually cytoplasm is squeezed from between membrane layers

which 2 neuroglia form myelin sheaths

schwann cells, oligodendrocytes

As the ________ nerve approaches the knee, it divides into two branches, the fibular nerve and the tibial nerve. perineal femoral pudendal brachial sciatic

sciatic

Each of the following nerves originates in the lumbar plexus, except the ________ nerve. femoral obturator genitofemoral saphenous sciatic

sciatic

Which of the following is NOT a function of the hypothalamus? emotional responses regulation of body temperature secretion of the hormone melatonin regulation of food intake

secretion of the hormone melatonin

Explain one of the funtions of the Pineal body:

seems to regulate the body's biological clock. A big part of this is regulated by the hormone melatonin, which is produced in the Pineal gland.

What is the function of the Vestibulocochlear nerve?

sense of hearing and equilibrium.

What is the function of the Olfactory nerve?

sense of smell

What is the function of the Facial nerve?

sense of taste. Motor impulses to facial muscles, tear, & salivary glands.

What is the function of the Optic nerve?

sense of vision

Which of the following is NOT a structural classification of neurons?

sensory

division of PNS

sensory (afferent) and motor (efferent)

which subdivision of the PNS is involved in relaying the feeling of a full stomach after a meal

sensory (afferent) division of PNS

what are somatic afferent fibres

sensory fibres conveying impulses from skin, skeletal muscles and joints

If the dorsal root of a spinal nerve is severed, the spinal cord would not be able to process information at that level. output to skeletal muscles would be blocked. output to visceral organs would be blocked. sensory input would be blocked. the brain would not be able to communicate with that level of the spinal cord

sensory input would be blocked.

what are three functions of the nervous system

sensory input, integration, motor output

What is the function of the Trigeminal nerve?

sensory inputs from face, teeth, and mouth. Control muscles in mouth.

optic nerve ( II )

sensory nerve that carries visual impulses from the eye to the brain ( E )

olfactory nerve

sensory nerve: functioning in the sense of smell ( C )

The posterior horns of the spinal cord contain mainly somatic motor nuclei. nerve tracts. sensory nuclei. autonomic motor nuclei. sympathetic nuclei.

sensory nuclei

The stimulus for graded potentials includes _______.

sensory stimuli and neurotransmitter

what are the subdivision of the PNS

sensory/afferent division, motor/efferent division

Which of the following describes the excitatory postsynaptic potential?

short distance depolarization

Which of the following describes the excitatory postsynaptic potential? moves membrane potential away from threshold short distance hyperpolarization short distance depolarization opens K+ or Cl- channels

short distance hyperpolarization

what are dendrites

short tapering diffusely branching extensions

what do thoracic nerves control and how many?

shoulders chest upper abdomen 12

Which of the following activities or sensations is not monitored by interoceptors? activities of the digestive system urinary activities cardiovascular activities taste sight

sight

The effects of lidocaine and tetrodotoxin were

similar, but tetrodotoxin had a greater effect

The effects of lidocaine and tetrodotoxin were _______.

similar, but tetrodotoxin had a greater effect

Hyperpolarization results from __________.

slow closing of voltage-gated K+ channels

Which of the following is least likely to increase the rate of diffusion?

small concentration gradient

Which of the following best characterizes depolarization?

small consecutive steps of Na+ penetration into the axon along its length

Which of the following best characterizes depolarization? small consecutive steps of Na+ penetration into the axon along its length small consecutive steps of Na+ exit from cytoplasm into extracellular fluid small consecutive steps of K+ entering the cytoplasm mass movement of Na+ into the axon cytoplasm from the cell body to the terminal

small consecutive steps of Na+ penetration into the axon along its length

what are microglia

small ovoid cells with relatively long thorny processes

microglia

small, ovoid cells with spiny processes Phagocytes that monitor the health of neurons

Type C nerve fiber

small-diameter, unmyelinated. Conduct at 2 m/s or less. Part of ANS

what are neuroglia

smaller cells that surround and wrap the more delicate neurons

how can neuroglia be distinguised

smaller size and darker staining nuclei

The movement of what ion is responsible for the local currents that depolarize other regions of the axon to threshold?

sodium (Na+)

Which of the following is true about the movement of ions across excitable living membranes?

sodium gates in the membrane can open in response to electrical potential changes

When cholinergic receptors are stimulated, chloride ions enter the postsynaptic neuron. sodium ions leave the postsynaptic neuron. sodium ions enter the postsynaptic neuron. norepinephrine deactivates acetylcholine. chloride ions leave the postsynaptic neuron.

sodium ions enter the postsynaptic neuron.

Establishing the resting membrane potential requires energy through the use of the _______.

sodium-potassium pump

That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.

somatic

The ________ nervous system controls the skeletal muscles. sympathetic autonomic afferent somatic parasympathetic

somatic

The anterior horns of the spinal cord contain mainly autonomic motor nuclei. sympathetic nuclei. nerve tracts. sensory nuclei. somatic motor nuclei.

somatic motor nuclei.

what is the somatic nervous system composed of

somatic nerve fibres that conduct impulses from CNS to skeletal muscles

what are the 2 parts of the motor division

somatic nervous system, autonomic nervous system

which subdivision of the PNS is involved in contracting the muscles to lift your arm

somatic nervous system, motor (efferent) division of PNS

Summation that results from the cumulative effect of multiple synapses at multiple places on the neuron is designated temporal summation. spatial summation. inhibition of the impulse. impulse transmission. hyperpolarization.

spatial summation.

what does the neuron cell body consist of

spherical nucleus with conspicuous nucleolus surrounded by cytoplasm

Which of these is not part of the peripheral nervous system (PNS)? afferent nerve fibers cranial nerves spinal nerves spinal cord

spinal cord

If the caudal portion of the neural tube failed to develop properly the ________. spinal cord may be affected telencephalon would cease development cranial nerves would not form hindbrain would not be present

spinal cord may be affected

Components of the Nervous System

spinal cord, brain, sensory receptors, nerves

The __________ is part of the CNS and the __________ is part of the PNS. spinal cord; spinal nerve cranial nerve; spinal nerve spinal nerve; spinal cord brain; spinal cord

spinal cord; spinal nerve

The specialized membranes that surround the spinal cord are termed the spinal mater. cranial mater. spinal meninges. epidural membranes. cranial meninges.

spinal meninges

A dorsal and ventral root of each spinal segment unite to form a cervical enlargement. lumbar enlargement. spinal ganglion. spinal meninx. spinal nerve.

spinal nerve.

Select the correct statement about serial processing

spinal reflexes are an example

what are neurons

structural units of nervous system, highly specialised cells that conduct messages in the form of nerve impulses from one part of the body to another

thalamus

structure in the diencephalon that processes all sensory information for except smell, and relays it to the cerebral cortex ( j )

The cerebrospinal fluid (CSF) circulates within the __________. subarachnoid space pia mater subdural space dura mater

subarachnoid space

Cerebrospinal fluid flows within the pia mater. subarachnoid space. arachnoid mater. filum terminale. dura mater.

subarachnoid space.

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the dura mater. cerebral ventricles. arachnoid mater. subarachnoid space. epidural space.

subarachnoid space.

Opioids relieve pain by blocking the release of substance Q. substance P. substance X. substance O. None of the answers are correct.

substance P.

increasing the strength of the stimulus applied to the sensory receptor increased _______.

the frequency of action potentials in the sensory neuron, the amount of neurotransmitter released at the axon terminal of the sensory neuron and the frequency of action potentials in the interneuron

lateral fissure

the gap that divides the temporal from the frontal and parietal lobes

An action potential in one segment of axon causes adjacent sections of axon membrane to reach threshold through what mechanism?

the generation of local currents

An action potential in one segment of axon causes adjacent sections of axon membrane to reach threshold through what mechanism? the generation of local currents Na+ ions diffusing across the membrane through leakage channels K+ ions diffusing through voltage-gated channels neurotransmitters causing chemically gated channels to open

the generation of local currents

All EXCEPT which of the following organs receives its innervation from fibers that synapse with preganglionic neurons in collateral ganglia?

the heart

The small space between the sending neuron and the receiving neuron is the

synaptic cleft

If the chemically-gated sodium channels in the postsynaptic membrane were completely blocked, smaller action potentials would result. the presynaptic neuron would release a different neurotransmitter. the presynaptic membrane would be unable to reach threshold. synaptic transmission would fail. release of neurotransmitter would stop.

synaptic transmission would fail.

Proteins in cell

synthesized there, don't dissolve in phospholipids of membrane

Axons terminate in a series of fine extensions known as dendrites. terminals. collaterals. telodendria. synapses.

telodendria.

The primary auditory cortex is located in the ________. frontal lobe prefrontal lobe parietal lobe temporal lobe

temporal lobe

When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs? decrease in speed of impulse transmission spatial summation temporal summation inhibition of the impulse hyperpolarization

temporal summation

REM sleep is associated with ________. decreased vital signs, such as heart rate and blood pressure decreased activity of the brain, especially the cerebral cortex decreased oxygen use, especially in the cerebral cortex temporary skeletal muscle inhibition except for ocular muscles and diaphragm

temporary skeletal muscle inhibition except for ocular muscles and diaphragm

The reflex that limits muscle tension is the __________ reflex. tendon reciprocal flexor stretch

tendon

The reflex that prevents a muscle from exerting too much tension is the ________ reflex. flexor stretch tendon reciprocal crossed extensor

tendon

the branches at the end of an axon are called what

terminal branches or telodendria

what is the end of an axon called

terminus

occipital lobe association area

the association area that is in charge of visual images w/ other sensory experiences

frontal lobe association areas

the association areas of concentrating, planning, problem solving, & judging are located?

parietal lobe association areas

the association areas of understanding speech and using words to express thought are located?

temporal lobe association areas

the association areas to remember music, visual scenes, complex patterns, & auditory are located?

non-dominant hemisphere controls *** not on test #7

the hemisphere of the brain that controls intuitive thought processes, nonverbal, motor tasks, interpreting musical, & visual patterns, emotions *** not on test #7

Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because the neurolemma is impermeable to most molecules. oligodendrocytes form a continuous myelin sheath around the axons. astrocytes form a capsule around neurons. ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons. the endothelium of CNS capillaries forms a blood-brain barrier.

the endothelium of CNS capillaries forms a blood-brain barrier.

what are neurons

the excitable nerve cells that transmit electrical signals

On what does consciousness depend?

the excitation of cortical neurons by impulses conducted to them by a network of neurons known as the Reticular Activiating System.

transverse fissure

the fissure that separates the cerebrum from the cerebellum

dominant hemisphere controls *** not on test #6

the hemisphere of the brain that controls speech, writing, reading, verbal skills, analytical skills, computational skills *** not on test #6

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________.

the impulse would spread bidirectionally

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________. the impulse would move to the axon terminal only muscle contraction would occur the impulse would spread bidirectionally the impulse would move to the axon terminal only, and the muscle contraction would occur

the impulse would spread bidirectionally

pia mater

the innermost meninge that tightly surrounds the brain & spinal cord ( 12 )

What is the infundibulum?

the part of the hypothalamus that forms a "stalk" between the hypothalamus and the pituitary gland.

Which of the following are gaps found along a myelin sheath?

nodes of Ranvier

what is are the gaps between the schwann cells on an axon in the PNS?

nodes of ranvier

Which of these neurotransmitters do adrenergic synapses use? nitric oxide GABA acetylcholine norepinephrine

norepinephrine

Which of these neurotransmitters is released at CNS adrenergic synapses? norepinephrine GABA serotonin adrenaline

norepinephrine

Adrenergic synapses release the neurotransmitter acetylcholine. serotonin. dopamine. GABA. norepinephrine.

norepinephrine.

The ventral rami form four major plexuses, including all of the following, except the ________ plexus. lumbar nuchal sacral brachial cervical

nuchal

Which of the following is not a chemical class of neurotransmitters?

nucleic acid

Which of the following is not a chemical class of neurotransmitters? acetycholine biogenic amine nucleic acid ATP and other purines amino acid

nucleic acid

Cell body

nucleus and metabolic center of the cell YES Nucleus NO centrioles

What are varicosities?

numerous swellings located at intervals along the axons of postganglionic neurons

what are axon collateral's

occasional branches along an axon, extend at right angles

Nuclei of cranial nerves V, VI, and VII are found in the ________. medulla midbrain cerebrum pon

pons

what is the neurilemma

portion of the Schwann cell that includes the exposed part of its plasma membrane- nucleus and cytoplasm of S cell end up as bulge external to myelin sheath

Immediately after an action potential has peaked, which cellular gates open?

potassium

The movement of which ion through leakage channels establishes the negative membrane potential?

potassium

What causes repolarization of the membrane potential during the action potential of a neuron?

potassium efflux (leaving the cell)

The most abundant intracellular cation is __________ while the most abundant extracellular anion is __________. sodium; chloride potassium; chloride potassium; protein anions sodium; protein anions

potassium; chloride

Which of the following is NOT a type of circuit?

pre-discharge circuits

Which of the following is NOT a type of circuit? reverberating circuits pre-discharge circuits converging circuits diverging circuits

pre-discharge circuits

Which part of the cerebral cortex is involved in intellect, cognition, recall, and personality? prefrontal cortex posterior association area limbic association area combined primary somatosensory cortex and somatosensory association cortex

prefrontal cortex

Loss of ability to perform skilled motor activities such as piano playing, with no paralysis or weakness in specific muscles, might suggest damage to the ________. spinal cord rubrospinal tracts primary motor cortex premotor cortex

premotor cortex

Which best represents synaptic transmission?

presynaptic axon to synapse to dendrite or postsynaptic cell body

Which best represents synaptic transmission? presynaptic axon to synapse to dendrite or postsynaptic cell body presynaptic axon to synapse to postsynaptic axon presynaptic axon to presynaptic cell body to dendrite presynaptic cell body to dendrite to synapse

presynaptic axon to synapse to dendrite or postsynaptic cell body

The neurotransmitter GABA blocks presynaptic voltage-gated calcium channels. Consequently, GABA produces __________. EPSPs presynaptic facilitation presynaptic inhibition IPSPs

presynaptic inhibition

In a synapse, neurotransmitters are stored in vesicles located in the __________.

presynaptic neuron

trochlear nerve ( IV )

primarily a motor nerve it carries motor impulses to oblique muscles of eye ( G )

hypoglossal nerve ( XII )

primarily a motor nerve: motor to move muscles of the tongue ( O )

accessory nerve ( XI )

primarily a motor nerve; to muscles of soft palate, pharynx, neck & back ( N )

The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____.

primary active transport

Which of the following are motor areas of the cerebral cortex that lie in the posterior part of the frontal lobes and control voluntary movement? primary somatosensory cortex; somatosensory association cortex; visual areas Broca's area; posterior association area; auditory areas; visual areas primary motor cortex; premotor cortex; prefrontal cortex; gustatory cortex primary motor cortex; premotor cortex; Broca's area; frontal eye field

primary motor cortex; premotor cortex; Broca's area; frontal eye field

Which of the following areas of the brain is responsible for spatial discrimination? primary somatosensory cortex vestibular cortex Broca's area gustatory cortex

primary somatosensory cortex

Which category of memory is involved when playing the piano? declarative motor emotional procedural

procedural

what is the central process

process entering the CNS

what is the function of microglia

processes touch nearby neurons to monitor health and when they sense injured neurons migrate towards them.

Oligodendrocytes

produce myelin sheath around nerve fibers in the central nervous system

Which of the following is not a recognized structural classification for neurons? multipolar pseudopolar anaxonic unipolar bipolar

pseudopolar

Which of these is not a neuron structural category? multipolar pseudopolar unipolar bipolar

pseudopolar

Two terms for the massive motor tracts serving voluntary movement are ________. segmental and nigrostriatal pyramidal and corticospinal extrapyramidal and rubrospinal supplementary and cerebellar-pontine

pyramidal and corticospinal

what do ependymal cells look like

range in shape form squamous to columnar and many are ciliated

ependymal cells

range in shape from squamous to columnar, many are ciliated They produce CSF, line the central cavities of the brain and spinal column, and create CSF flow

After acetylcholinesterase acts, the synaptic terminal reabsorbs axoplasm. reabsorbs the acetate. reabsorbs the acetylcholine. reabsorbs the choline. pinches off and a new terminal grows

reabsorbs the choline.

Neuron & parts

receive stimuli and transmit action potentials -cell body:soma -dendrites: input -axons: output

The receptor potential is generated at the

receiving region

Which of the following processes allows cells to concentrate material that is present only in very small amounts in the extracellular fluid?

receptor-mediated endocytosis

Spinal interneurons inhibit antagonist motor neurons in a process called a crossed extensor reflex. a stretch reflex. reciprocal inhibition. reverberating circuits. a tendon reflex.

reciprocal inhibition.

Which of the following would you not find in normal cerebrospinal fluid? red blood cells protein glucose potassium

red blood cells

Which of the following is (are) involved with motor activity (either initiation or coordination)? Wernicke's area postcentral gyrus red nuclei gustatory cortex

red nuclei

Which of the following is NOT an adaptation that occurs at the neuromuscular junction in response to exercise?

reduced degradation of acetylcholine in the neuromuscular junction

Which of the following is NOT one of the basic functions of the nervous system?

regulation of neurogenesis

Which of the following is NOT one of the basic functions of the nervous system? integration of sensory input monitor changes occurring both inside and outside the body control the activity of muscles and glands regulation of neurogenesis

regulation of neurogenesis

Clenching the fists often enhances the knee jerk reflex. This is an example of __________. stimulus response enhancement reinforcement nerve injury

reinforcement

Neuroglia perform all of these functions except __________. secrete CSF provide supportive framework release neurotransmitters regulate extracellular fluid composition

release neurotransmitters

If the __________ muscles are affected, then the person may have to be placed __________.

respiratory; respirator

Which of the following describes the nervous system integrative function? analyzes sensory information, stores information, makes decisions responds to stimuli by gland secretion or muscle contraction senses changes in the environment

analyzes sensory information, stores information, makes decisions

Neurons that are rare, small, and lack features that distinguish dendrites from axons are called anaxonic. bipolar. multipolar. unipolar. tripolar.

anaxonic.

During the relative refractory period,

another action potential can be generated provided the stimulus is large enough

knee-jerk reflex

another name for patellar reflex; this is a monosynaptic reflex (no interneuron); helps maintain an upright posture

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon? a) the number of axon collaterals extending from a truncated axon b) degree of myelination of the axon c) whether the axon is located in the central nervous system or in the peripheral nervous system d) length of the axon

b) degree of myelination of the axon

Collections of nerve cell bodies outside the central nervous system are called _________. a) nuclei b) ganglia c) tracts d) nerves

b) ganglia

The two types of receptors that bind acetylcholine are __________ and _______ receptors. a) alpha; beta b) nicotinic; muscarinic c) caffeinic; muscarinic d) nicotinic; caffeinic

b) nicotinic; muscarinic

Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in her lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compressed? descending tracts the anterior gray commissures the anterior gray horns ascending tracts the anterior white commissures

ascending tracts

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.

association neuron

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. association neuron glial cell efferent neuron afferent neuron

association neuron

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________.

astrocytes

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. microglia oligodendrocytes Schwann cells astrocytes

astrocytes

Which is the largest and most abundant type of neuroglia? astrocytes ependymal cells satellite cells oligodendrocytes

astrocytes

Which neuroglia are the most abundant and versatile of the glial cells?

astrocytes

Which neuroglia are the most abundant and versatile of the glial cells? ependymal cells Schwann cells oligodendrocytes astrocytes

astrocytes

Which of the following types of glial cells are the most abundant and versatile, and aid in making exchanges between capillaries and neurons?

astrocytes

what is the most abundant and versatile glial cell

astrocytes

Neuroglia of CNS

astrocytes, epydymal, oligondendryte, microglia

The largest and most numerous of the glial cells in the central nervous system are the microglia. ependymal cells. satellite cells. oligodendrocytes. astrocytes.

astrocytes.

The neuroglial cells that participate in maintaining the blood-brain barrier are the oligodendrocytes. microglia. Schwann cells. ependymal cells. astrocytes.

astrocytes.

Where are action potentials regenerated as they propagate along an unmyelinated axon?

at every segment of the axon

The release of neurotransmitter occurs _______.

at the axon terminal

During what part of the action potential do voltage-gated Na+ channels begin to inactivate (their inactivation gates close)?

at the end of the depolarization phase, as the membrane potential approaches its peak value

Where are action potentials regenerated as they propagate along a myelinated axon?

at the nodes

Where are action potentials regenerated as they propagate along a myelinated axon?

at the nodes of Ranvier

Where are action potentials regenerated as they propagate along a myelinated axon? at the nodes of Ranvier at every segment of the axon at the axon hillock at the myelinated segments

at the nodes of Ranvier

An excitatory postsynaptic potential occurs _______.

at the receiving end of the interneuron

Myasthenia gravis is a medical condition of __________ etiology that results in __________ muscle weakening.

autoimmune; skeletal muscle

reflexes

automatic, subconcious response to a stimuli

which subdivision of the PNS is involved in increasing your heart rate

autonomic nervous system, motor (efferent) division of PNS

The conducting region of the neuron is the

axon

The conducting region of the neuron is the _______

axon

The part of a neuron that conducts impulses away from its cell body is called a(n) ________.

axon

Which of the following is the conducting region of the neuron?

axon

Which of the following is the conducting region of the neuron? terminal boutons axon soma dendrites

axon

Which part of the neuron is responsible for generating a nerve impulse?

axon

Which part of the neuron is responsible for generating a nerve impulse? soma axon dendrite chromatophilic substance

axon

what is the conduction region of the neuron

axon

what can emerge from the nodes of ranvier

axon collaterals

EPSPs and IPSPs summate at the __________. synaptic knob postsynaptic receptors axon hillock electrical synapse

axon hillock

The simplest level of information processing takes place at the __________. axon terminals axon hillock soma dendrites

axon hillock

Where in the neuron is an action potential initially generated?

axon hillock

The axon is connected to the soma at the collaterals. synaptic terminal. telodendria. synapse. axon hillock.

axon hillock.

The site in the neuron where EPSPs and IPSPs are integrated is the synaptic terminal. electrical synapse. chemical synapse. axon hillock. dendritic membrane

axon hillock.

what is the secretory region of the neuron

axon terminals

what are the knoblike distal ending of the terminal branches called

axon terminals, synaptic knobs, boutons

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. axon Schwann cell neurolemma dendrite

axon\

The ventral root of a spinal nerve contains axons of sensory neurons. axons of motor neurons. cell bodies of motor neurons. cell bodies of sensory neurons. interneurons.

axons of motor neurons.

The dorsal root of a spinal nerve contains cell bodies of motor neurons. axons of sensory neurons. cell bodies of sensory neurons. axons of motor neurons. interneurons.

axons of sensory neurons.

what are visceral afferent fibres

axons transmitting impulses from the visceral organs- organs within the ventral body cavity

Which of the following are gaps found along a myelin sheath? a) Neurilemma b) Nodes of Ranvier c) Telodendria d) Axolemma

b) Nodes of Ranvier

Preparing the body for the "fight-or-flight" response is the role of the _______. a) somatic nervous system b) sympathetic nervous system c) cerebrum d) parasympathetic nervous system

b) sympathetic nervous system

what is the purpose of the ependymal cells cillia

beating cilia helps to circulate cerebrospinal fluid that cushions the brain and spinal cord

inhibition

because cell M1 regulates the ability of the presynaptic cell to release transmitter, it is called PRESYNAPTIC _____.

why do CNS myelin sheaths lack neurilemma

because cell extensions are doing the coiling and the squeezed out cytoplasm is forced not peripherally but back towards the centrally located nucleus

Which of the following is not true of graded potentials? a) They can be called postsynaptic potentials. b) They increase amplitude as they move away from the stimulus point. c) They are short-lived. d) They can form on receptor endings.

b) They increase amplitude as they move away from the stimulus point.

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. a) Schwann cell b) axon c) dendrite d) neurolemma

b) axon

Spinal nerves are purely motor. purely sensory. involuntary. both sensory and motor. interneuronal.

both sensory and motor

During depolarization, which gradient(s) move(s) Na+ into the cell?

both the electrical and chemical gradients

In which plexus does the ulnar nerve arise? lumbar cranial cervical brachial sacral

brachial

The ventral rami of spinal nerves C5 to T1 contribute fibers to the ________ plexus. lumbar sacral cervical brachial thoracic

brachial

The term central nervous system refers to the ________.

brain and spinal cord

The term central nervous system refers to the ________. brain and spinal cord brain, spinal cord, and peripheral nerves spinal cord and spinal nerves peripheral and spinal nerves

brain and spinal cord

what is in the CNS

brain and spinal cord, integrating and command centre

A nerve is _______.

bundle of axons

nerve

bundle of axons and their sheaths that connects CNS to sensory receptors, muscles, and glands (cranial and spinal)

What is the ventral nerve root?

bundle of nerve fibers carrying motor information out of the cord.

The white matter of the spinal cord contains both axons and dendrites. sensory and motor nuclei. interneurons. bundles of axons with common origins, destinations, and functions. bundles of dendrites with common origins, destinations, and functions.

bundles of axons with common origins, destinations, and functions.

what are neurofibrils

bundles of intermediate filaments

describe sensory/afferent neurons

transmit impulses from sensory receptors in the skin or internal organs toward or into the CNS, mostly all are unipolar and cell bodies located in sensory ganglia outside CNS, peripheral processes long

The region on the neuron where action potentials are generated is called the ______.

trigger zone

A disturbance of posture, muscle tremors at rest, and uncontrolled muscle contraction are all symptoms of damage to the basal nuclei. True False

true

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons. True False

true

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane

true

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane. True False

true

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. True False

true

Cell bodies of the somatic motor neurons of the spinal nerves are located in the ventral horn of the spinal cord. True False

true

Cerebrospinal fluid circulates within the ventricles of the brain and in the subarachnoid space outside the brain. True False

true

During depolarization, the inside of the neuron's membrane becomes less negative. True False

true

Efferent nerve fibers may be described as motor nerve fibers. True False

true

Embryonic damage to the mesencephalon could result in improper formation of the midbrain. True False

true

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them. True False

true

In general, information flows from sensory receptors to the appropriate primary sensory cortex. True Fals

true

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier. True False

true

Most of the ascending and descending pathways to and from the brain cross over from one side of the body to the other. True False

true

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte. True False

true

NREM sleep normally exhibits four distinct stages, which appear to alternate. True False

true

Neurons in the CNS are organized into functional groups. True False

true

Nuclei relating to the startle reflex are located in the corpora quadrigemina of the midbrain. True False

true

One functional center found within the medulla oblongata is a respiratory center involved in the control of the rate and depth of breathing. True False

true

Opening K+ or Cl- channels in a postsynaptic membrane would produce an inhibitory postsynaptic potential (IPSP). True False

true

Reflexes are rapid, automatic responses to stimuli.

true

Reflexes are rapid, automatic responses to stimuli. True False

true

Some neurotransmitters can be either excitatory or inhibitory depending upon the receptor. True False

true

Specific motor and sensory functions are localized in specific areas called domains, whereas memory and language have overlapping domains. True False

true

The adult spinal cord ends between L1 and L2. True False

true

The first obvious sign that the nervous system is forming in the embryo is the thickening of the surface ectoderm to form the neural plate. True False

true

The left cerebral hemisphere is usually dominant. True False

true

The limbic system acts as our emotional, or affective, brain. True False

true

The oligodendrocytes can myelinate several axons. True False

true

The overlapping functions of the nervous system are sensory input, integration, and motor output. True False

true

The primary visual cortex contains a map of visual space. True False

true

The term cerebral dominance designates the hemisphere that is dominant for language. True False

true

The terms fainting and syncope describe the same thing. True False

true

Unipolar neurons have axons structurally divided into peripheral and central processes. True False

true

Neurotransmitters ready for release are stored in synaptic terminals. vesicles. mitochondria. neurosomes. telodendria.

vesicles

Important nuclei of the indirect (multineural) system that receive impulses from the equilibrium apparatus of the inner ear and help to maintain balance by varying muscle tone of postural muscles are the ________. reticular nuclei vestibular nuclei red nuclei superior colliculi

vestibular nuclei

A reflex that leads to secretion of saliva is a(n) __________ reflex. acquired motor somatic visceral

visceral

Which of the following best describes the hypothalamus? somatic motor control center gateway to the cerebellum visceral control center of the body relay station for the special senses

visceral control center of the body

what does the ANS consist of

visceral motor nerve fibres that regulate the activity of smooth muscles, cardiac muscles and glands

The area of the cortex that is responsible for sensations of the full bladder and the feeling that your lungs will burst when you hold your breath too long is the ________. gustatory cortex vestibular cortex olfactory cortex visceral sensory area

visceral sensory area

Which of the following is NOT one of the three types of functional areas within the cerebral cortex? sensory areas motor areas association areas visual areas

visual areas

An individual who could trace a picture of a bicycle with his or her finger but could not recognize it as a bicycle is most likely to have sustained damage to the ________. primary visual area visual association area lateral geniculate body calcarine cortex

visual association area

In this simulation, ___________________ will be used to stimulate the axon.

voltage

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

voltage- gated channels

An action potential releases neurotransmitter from a neuron by opening which of the following channels?

voltage-gated Ca2+ channels

The depolarization phase of an action potential results from the opening of which channels?

voltage-gated Na+ channels

In response to an action potential, what type of channels open in the motor neuron terminal buttons at the neuromuscular junction to cause neurotransmitter release?

voltage-gated calcium channel

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials?

voltage-gated channel

Which of the following membrane ion channels open and close in response to changes in the membrane potential?

voltage-gated channels

When an action potential arrives at the end of the axon terminal, a series of events take place that result in the release of neurotransmitter from the presynaptic axon. Select the answer that correctly describes the primary stimulus for vesicles to move towards the cell membrane and eventually release their contents.

voltage-gated membrane channels open, and Ca+2 enters the cytoplasm, increasing intracellular calcium

What is primarily responsible for the brief hyperpolarization near the end of the action potential?

voltage-gated potassium channels taking some time to close in response to the negative membrane potential

An action potential requires _______.

voltage-gated sodium channels to open and sodium to flow with its electrochemical gradient

Somatic nervous system

voluntary

axoaxonic

what type of synapse? Axon of presynaptic neuron synapses with presynaptic terminal of another neuron (e.g. many synapses of CNS).

short term memory *** not on test #8

when a closed circuit of neurons is stimulated over & over in order to maintain memory; when stimulation ceases so does the memory *** not on test #8

describe unmyelintated cells

when schwann cells surround peripheral nerve fibres but the coiling process does not occur. typically thin fibres

axon terminals

where axons end

what is the axon hillock

where the axon rises from

Which of the following does not influence the time necessary for a nerve impulse to be transmitted? diameter of the axon presence or absence of nodes length of the axon whether or not the impulse begins in the CNS presence or absence of a myelin sheath

whether or not the impulse begins in the CNS

Reflexes can be classified according to all of the following, except the motor response. where information processing occurs. their development. the complexity of the neural circuit. whether they are sensory or motor.

whether they are sensory or motor.

Autonomic motor nuerons

GVE

Classified as sympathetic or parasympathetic

GVE

Efferent motor flow to cardiac muscle, smooth muscle of visceral organs and blood vessels, and glads

GVE

Involuntary motor

GVE

Neurons of the autonomic nervous system

GVE

cell body, processies

Major regions of neurons

What is the peripheral bulge of the Schwann cell cytoplasm called?

Neurilemma [where the jelly roll bulges out]

What is the stimulus in the patellar tendon reflex

Striking the patellar tendon

How is Cerebrospinal Fluid formed?

Structures called choroid plexus separate some fluid from the blood. That fluid is CSF.

Upper masses of the corpora quadrigemina which contain the centers for certain visual reflexes

Superior colliculi

How much CSF do humans secrete daily

500 ml

Which areas of this neuron would be classified as receptive regions?

Cell body

Amitotic

Cells do not replace themselves.

Norepinephrine-releasing fibers are called cholinergic fibers T/F

False

Cannot convey distinctions between hot vs. cold, fine vs. course pressure

GVA

Mainly subconscious (exception: visceral pain, nausea, sensation of fullness)

GVA

Sensory nuerons with cell bodies loacated in the dorsal/posterior root ganglion (ass. with GVE)

GVA

Sensory receptors located in visceral organs, blood vessels, and glands

GVA

Transmit info from visceral organs to CNS

GVA

Anterior branches of the spinal cord form complex networks called

Plexuses

Appears as a rounded bulge on the underside of the brainstem where it separates the midbrain from the medulla oblongata

Pons

Relays information from spinal nerves to higher brain centers and the cerebrum & the cerebellum..also the center for the rhythm of breathing

Pons

Define Thalamus:

Portion of the Diencephalon; mass of gray matter involved in relay of sensory information, emotion, arousal and complex reflexes.

Define Brain Stem:

Portion of the brain made up of the midbrain, pons, and medulla oblongata.

What functional area of the cerebral cortex serves as the primary area for the general somatic senses?

Postcentral Gyrus

The posterior and anterior wings of the gray matter are called the

Posterior & anterior horns

Location of the fasciculus

Posterior funiculi

Spinal nerves branch into 3 different branches called

Posterior, anterior & visceral

Fibers that leave the ganglion to synapse on the visceral effector are

Postganglionic fibers

Define POSTsynaptic neuron

Postsynaptic neuron: transmits impulses away from the synapse

Fibers that leave the CNS to synapse at the ganglion are

Preganglionic fibers

Sympathetic

Prepares body for physical activity.

________ neurons form the afferent division of the PNS. Sensory Neural sensory Somatic sensory Visceral sensory Motor

Sensory

Neuron Classification Functional

Sensory (afferent) — transmit impulses toward the CNS Motor (efferent) — carry impulses away from the CNS Interneurons — shuttle signals through CNS pathways and perform integration

__________ needs neural stimulation/excitation before it can contract; the other forms of muscle can also be stimulated by hormones and/or other chemicals.

Skeletal muscle

Describe the structure and function of Microglial cells

Small, ovoid cells with thorny processes Migrate toward injured neurons Phagocytize microorganisms and neuronal debris M = M: microglia macrophage

Saltatory conduction is made possible by ________.

The myelin sheath

Fissure that separates the cerebrum from the cerebellum

Transverse fissure

The cytoplasm that surrounds the nucleus of a neuron is called the protoplasm. neuroplasm. perikaryon. nucleoplasm. sarcoplasm.

perikaryon.

The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the endosteum. endoneurium. epimysium. epineurium. perineurium.

perineurium.

The nervous tissue outside of the central nervous system composes the ________ nervous system.

peripheral

The ________ nerve, which arises in the cervical plexus, innervates the diaphragm. sciatic radial phrenic lesser occipital ansa cervicalis

phrenic

The brachial plexus gives rise to all of the following nerves, except the median. radial. musculocutaneous. ulnar. phrenic

phrenic

The layer of the meninges in direct contact with the spinal cord is the dura mater. subarachnoid space. arachnoid. pia mater. choroid plexus.

pia mater

Blood vessels that supply the spinal cord run along the surface of the epidural space. pia mater. subarachnoid space. dura mater. subdural space.

pia mater.

The CSF is confined between the __________ and the __________. pia mater; dura mater epidural space; subdural space dura mater; arachnoid mater pia mater; arachnoid mater

pia mater; arachnoid mater

what is the site of electrical signalling in a neuron

plasma membrane

The complex, interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a(n) plexus. lateral nerve. autonomic nerve. dermatome. tract.

plexus.

Enteric

plexuses within the wall of the digestive tract

corpus callosum

the thick flat bundle of axons that connects the two cerebral hemispheres

ascending tract

the tract in the white matter of the spinal cord that carries sensory information towards the brain

lateral spinothalamic

the tracts in the lateral funiculi of the spinal cord that carry afferent nerve fibers to the thalamus

fasciculus cuneatus

the tracts in the posterior funiculi of spinal cord; transmits fine touch, and proprioception information from sensory nerves

During an action potential of a neuron, what directly causes the different channels to open and close?

the transmembrane potential (voltage)

three parts of the brainstem

these three parts (midbrain / pons / medulla oblongata) A, B, C, D

Which of the following is not characteristic of neurons?

they are mitotic

What are the somatic senses?

they are the general (not specialized) senses. They do not require complex sensory organs.

When calcium ions enter the synaptic terminal,

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

why are unipolar neurons more accurately called pseudo unipolar neurons

they originate as bipolar neurons then during early embryonic development the two process converge and partially fuse to form short single process that issues from the cell body

What are descending tracts?

tracts conduct impulses down the cord away from the brain

what are bundles of neuron processes called

tracts in the CNS, nerves in the PNS

What are ascending tracts?

tracts that conduct impulses to the brain

oligodendrocytes function

1. cells that produce myelin in the CNS 2. produce grow-inhibitory proteins that inhibit the growth of injured neuons

Define Synapse

A junction that mediates information transfer from one neuron: - To another neuron, or - To an effector cell

Synapse

A junction that mediates information transfer from one neuron: To another neuron To an effector cell

Saltatory conduction

"jumping" of impulse from node to node

Which of the following occurred in the presence of tetrodotoxin?

An action potential was always seen at R1.

Describe the structure and function of Astrocyte cells

*SUPPORT / COMMUNICATION* Most abundant, versatile, and highly branched glial cells Cling to neurons, synaptic endings, and capillaries Support and brace neurons Help determine capillary permeability Guide migration of young neurons Control the chemical environment Participate in information processing in the brain Communication between capillary & neurons A = A: astrocytes attach to arteries

In a typical neuron, what is the equilibrium potential for sodium?

+66mV

How many segments does the spinal cord have? What arises from each segment?

- 31 - a pair of spinal nerves arises from each segment.

Where does the midbrain lie? Of what is it composed?

- Above the pons and below the cerebellum. - Composed of white matter (tracts) and reticular formation.

Where does the spinal cord begin and end? How long is the average spinal cord?

- Begins at the Foramen Magnum and ends at the lower border of the 1st lumbar vertebra. - 18 inches

What is the difference between Cholinergic and Adrenergic Fibers?

- Cholinergic fibers are nerve fibers which secrete Acetylcholine. Mostly parasympathetic nerve fibers. - Adrenergic Fibers secrete norepinephrine (noradrenaline). Mostly sympathetic fibers.

Describe the cause and treatment of epilepsy:

- Epilespy is a seizure disorder - Cause: chemical imbalance, tumors, sometimes idiopathic. (Often diagnosed and specifically located by using EEG.) - Treatment: anti-convulsive drugs such as phenobarbital that block neurotransmitters in the affected area of the brain.

What is Internal Hydrocephalus and how is it treated in infants?

- Excess of CSF in lateral and 3rd ventricles beacuse drainage is blocked. - Increased pressure leads to coma and/or death. - Treat by catheterize the ventricle(s) and clear the obstruction.

What are arachnoid villi and what do they do?

- Finger-like projections of the arachnoid membrane. - They absorb CSF and pass it into veins in the arachnoid membrane.

Where do cranial nerves arise, and where do they terminate?

Arise from underside of brain. Terminate in the head, neck, and trunk.

Describe the Pia Mater:

- Innermost layer - Adheres to the outer layer of the brain and spinal cord and contains blood vessels.

What happens to sensory info sent to the primary sensory areas in the cortex?

- It is relayed to various sensory association areas (and other parts of the brain) where it is "compared and evaluated". - The cortext intergrates these separate bits of information into the whole perception.

Describe the Arachnoid Membrane:

- Middle layer - Delicate - Cobweb-like layer

What are medullary nuclei and where are they?

- Nuclei (clusters of neuron cell bodies), some of which control the cardiac, respiratory, and vasomotor activities. - Others control non-vital reflex centers associated with coughing, sneezing, swallowing, and vomiting.

Describe the Dura Mater:

- Outermost layer - Strong - White fibrous connective tissue

What is the dorsal nerve root?

- bundle of nerve fibers carrying sensory information into the spinal cord. - located on the dorsal side of cord

What is the function of axon terminals?

- Secretory regions of neuron - Release neurotransmitters to excite or inhibit other cells

Why are tracts both structural and functional organizations of nerve fibers?

- Structural because all axons in a tract originate from cell bodies in the same structure and all axons terminate in the same structure. - Functional because all axons in one tract serve one general function (ex: spinothalamic tracts are sensory. All transmit impulses that produce sensation of crude touch, pain, and temperature.)

What are Sulci and Gyri?

- Sulci are grooves. - Gyri are raised areas.

What is a CVA?

- a cerebrovascular acccident. Also known as a stroke. - is caused by bleeding or blockage of cerebral blood vessels. - causes loss of oxygen to brain.

Where does the pons lie?

- between the medulla and the midbrain. - composed of white matter (tracts) and reticular formation.

Describe the basic structure and function of the white matter in the spinal cord:

- each side of the cord has 3 columns (or Funiculi) of white matter: Anterior, Lateral,& Posterior. - each column is subdivided into tracts. - the tracts carry signals from the brain to the spinal cord and from the spinal cord to the brain. - Tract's name tells you 3 things: 1) where it is (anterior, lateral, or posterior side of cord) 2) where it originates 3) where it terminates Ex: Anterior Spinocerebellar -- front side of cord, starts in spinal cord, ends in cerebellum

What are the lumbar and cervical enlargements and what structures arise form them?

- places where the spinal cord thickens in the cervical and lumbar vertebrae. - the cervical enlargement gives rise to the major nerves going to the arms and neck. - the lumbar enlargement gives rise to major nerves in the legs and feet. Divide the cord into left and right halves.

Define Hypothalamus:

- portion of the diencephalon. - vital neuroendocrine and autonomic control center.

Describe the basic structure and function of the core of grey matter in the spinal cord:

- shaped like the letter H. - limbs of the H are called the Anterior, Lateral, and Posterior horms of grey matter or grey columns. - consist primarily of the cell bodies of interneurons and motor nuerons. - Primary job is to function a reflex arcs.

Neuroglia found in the CNS that bind axons and blood vessels to each other are called ________.

Astro-cytes

Define Language functions: In which lobes are the speech centers foound?

- the ability to speak and write words and the ability to understand spoken and written word.

function of blood-brain barrier

1. protects cerebrospinal fluid (CSF) from blood-born toxins and drugs 2. allows exchange of gases and nutrients 3. removes wastes

What is the cerebral cortex and how deep is it?

- the surface of the cerebrum, which is made up of gray matter. - 2-4mm (1/12 to 1/6 of an inch)

Postsynaptic neuron

- transmits impulses away from the synapse

Around what transmembrane potential does threshold commonly occur?

-60 mV

Assume you have a membrane with only potassium leak channels. The RMP is -90mV. Predict the RMP if we add leak channels. The most likely RMP value of is __________.

-70 mV

What is the value for the resting membrane potential for most neurons?

-70 mV

In a typical neuron, what is the equilibrium potential for potassium?

-90mV

Propagation of action potential in unmyelinated

-Action potential in one site causes action potential at the next location (domino affect)

Absolute Refractory Period

-Complete insensitivity exists to another stimulus -No matter how large the stimulus, a second action potential cannot be produced

vermis

-connects the two hemispheres of the cerebellar cortex (grey matter)

Astrocytes

-cover the surfaces of neurons and blood vessels and the pia mater -Blood-brain barrier: protects neurons from toxic substances, allows the exchange of nutrients and waste between neurons and blood, prevents fluctuations in the composition of the blood from affecting the functions of the brain

Excitatory postsynaptic potential

-depolarization occurs

autonomic nervous system

-from CNS to cardiac and smooth muscle & glands -2 neuron system CNS->ganglion->effector -divisions are paroxysm, sym, and enteric

somatic nervous system

-from CNS to skeletal -voluntary -single neuron system

In brain: In spinal cord:

-gray is outer, white is inner -white is outer, gray is inner

Inhibitory postsynaptic potential

-hyperpolarization

ependymal

-line the cavities of the brain a& central canal of spinal cord -form the choroid plexus

Neurotransmitter Removal

-method depends of neurotransmitter -ACh: acetylcholinesterase splits ACh into acetic acid and choline. Choline recycled within presynaptic neuron.

microglia

-phagocytize foreign substances

Myelinated axons

-protects and insults axons -speeds transmission -not continuous (nodes of ravine)

Satellite cells

-surround neuron cell bodies in sensory ganglia, provide support and nutrients

oliogodendrocytes

-wrap around axons -can form myelin sheaths and wrap around multiple axons

Schwann cells

-wrap around portion of only one axon to form myelin sheath

Approximately how fast do action potentials propagate in unmyelinated axons in humans?

1 meter per second

The spinal cord tapers to a point and terminates near the intervertebral disc that separates btwn what 2 vertebrae

1&2 lumbar

List the 3 general functions of the cerebellum:

1) Acts with motor areas in cerebrum to produce skilled movements by coordinating the activities of groups of muscles. 2) Helps control posture. 3) Controls skeletal muscles to maintain equilibrium.

How much CSF is in the nervous system at any given time

140 ml

Describe the cause and progress of Alzheimer's disease and Huntington's disease:

1) Alzheimer's disease - lesions develop in the cortex during middle to late adulthood. Leads to dementia. Cause is unknown and there is no cure. 2) Huntington's disease - deterioration of the cerebral cortex. Begins age 30-40. Death usually by age 55. Caused by a dominant gene on non-sex chromosome. No cure yet.

List the 4 types of brain waves in order from fastest to slowest: When is each type generally seen?

1) Beta - seen when the brain is engaged in mental activities. 2) Alpha - awake. eyes closed. relaxed state. cerebrum is "idling". 3) Theta - drowsiness. 4) Delta - deep sleep.

Describe the path of CSF from its formation by a choroid plexus to its reabsorption into the blood:

1) CSF formed in 1st & 2nd ventricles passes into a tube called the interventricular foramen. 2) Interventricular foramen --> 3rd ventricle. 3) 3rd ventricle --> a tube called the cerebral aqueduct. 4) cerebral aqueduct --> 4th ventricle 5) 4th ventricle --> Central canal of spinal cord; Left lateral, right lateral, & median foramen. 6) Left lateral, right lateral, & median foramen --> Cisterna Magna 7) Cisternal Magna --> subarachnoid space and arachnoid villi. 8) arachnoid villi --> venous blood

List the 4 major brain divisions:

1) Cerebrum 2) Cerebellum 3) Diencephalon 4) Brain Stem

What are the subdivisions of the Cerebrum?

1) Cortex 2) Corpus Callosum

List the 3 layers of meninges in order from the outermost layer to the innermost layer:

1) Dura Mater 2) Arachnoid Membrane 3) Pia Mater

List 3 important spaces between and around the meninges:

1) Epidural space 2) Subdural space 3) Subarachnoid space

List the 3 important inward extensions of the dura mater and identify the structures that each separates:

1) Falx Cerebri: separates the left and right halves of the cerebrum. 2) Falx Cerebelli: seperates the left and right halves of the cerebellum. 3) Tentorium Cerebelli: Separates the cerebellum from the cerebrum.

List the 5 major cerebral lobes andd their locations:

1) Frontal Lobes - under the frontal bone. 2) Parietal Lobes - under the parietal bones. 3) Temporal Lobes - under the temporal bones. 4) Occipital Lobes - under the occipital bone. 5) Insula - under the lateral fissures.

How does the thalamus relay sensory impulses on their way to the cerebral cortex?

1) Impulses from spinal cord, brain stem, cerebellum, basal ganglia, and various parts of the cerebrum 2) go to the thalamic nuclei 3) then to all areas of the cerebral cortex

List the major descending tracts and their functions:

1) Lateral & Anterior Corticospinal Tracts - voluntary muscle. 2) Lateral, Anterior, & Medial Reticulospinal Tracts - conducts impulses controlling muscle tone and sweat gland activity. 3) Rubrospinal Tracts - transmits impulses that coordinate body movements and maintenance of posture.

List the major ascending tracts and their functions:

1) Lateral & Anterior Spinothalamic - touch, temp, pain, and pressure. 2) Fasiculi Gracilis & Cuneatus - discriminating touch, pressure, & conscious sensation of position and movement of body parts (Kinesthesia). 3) Spinocerebellar Tracts - sensory inputs from muscles of lower limbs and trunk to cerebellum for muscle movement coordination.

List the 4 major cerebral fissures and the structures they divide:

1) Longitudinal Fissure - deepest groove in the cerebrum. Divides the cerebrum into 2 hemispheres. 2) Central Sulcus (Fissure of Rolando) - groove between the frontal and parietal lobes. 3) Lateral Fissure (Fissure of Sylvius) - A deep groove between the temporal lobe below and the frontal and parietal lobes above. Insula lies deep in this fissure. 4) Parietooccipital Fissure - Groove that separates occipital lobe from two parietal lobes.

What are the subdivisions of the Brain Stem?

1) Midbrain 2) Pons 3) Medulla Oblongata

List the 12 cranial nerve pairs:

1) Olfactory 2) Optic 3) Oculomotor 4) Trochlear 5) Trigeminal 6) Abductens 7) Facial 8) Vestibulocochlear 9) Glossopharyngeal 10) Vagus 11) Accesory 12) Hypoglossal

What are the two protective coverings of the brain and spinal cord?

1) Outer covering: Cranial bones which protect the brain and Vertebrae which protect the spinal cord. 2) Inner covering: the Meninges

List the 3 major cerebral tracts and explain what each does:

1) Projection Tracts - extensions of ascending and descending tracts from the spinal cord. 2) Association Tracts - extend from one convolution (gyrus) to another. 3) Commissural Tracts - extend from one convolution to the corresponding convolution in the other hemisphere.

List and describe the subdivisions of the PNS:

1) Somatic Nevous System - the cranial and spinal nerves that connect the CNS to the skin & skeletal muscles. Controls conscious activities. 2) Autonomic Nervous System - fibers connecting CNS to viscera. Controls unconscious activies.

Name the 4 parts of the diencephalon:

1) Thalamus 2) Hypothalamus 3) Pineal Body 4) Optic Chiasma

What are the subdivisions of the Diencephalon?

1) Thalamus 2) Pineal Body 3) Hypothalamus

Name 4 intergrative cerebral function:

1) consciousness 2) Language 3) emotions 4) memory

What 2 characteristics are used to classify brain waves?

1) frequency of waves (cycles/sec.) 2) amplitude. height of brain wave. voltage of the impulses.

List the 7 functions of the hypothalamus:

1) helps control and integrate autonomic activities. 2) the major relay station between the cerebral cortex and lower autonomic centers (parts of the brain stem and spinal cord). 3) some neurons make the hormones released by the posterior pituitary gland (ADH/water balance). 4) other neurons make other hormones which cause the anterior pituitary gland to release its hormones. 5) plays essential tole in maintaining the waking state. 6) helps regulate appetite. 7) has crucial role in maintaining normal body temperature.

List 2 current concepts about the role of the reticular activating system in consciousness:

1) it functions as the arousal or alerting system for the cerebral cortex 2) its functioning is crucial for maintaining consciousness.

List the primary functions of the thalamus:

1) plays 2 parts in mechanism responsible for sensations: - Produces conscious recognition of crude pain, temp. and touch. - Relays all kinds of seonsory impulses, except olfactory, to the cerebrum. 2) Associates sensory impulses with feelings of pleasantness and unpleasantness. 3) Plays a part in arousal or alerting mechanism 4) Plays a part in production of complex movements

What are the 2 general functions of the spinal cord?

1) provides routes for nerve impulses to travel to the brain or away from the brain. 2) serves as the reflex center for all spinal reflexes

List 4 of the Somatic senses:

1) touch 2) pressure 3) temperature 4) body position (proprioception)

function of autonomic motor system

1. "involuntary" nervous system 2. innervates cardiac muscle, smooth muscle, and glands from the CNS

function of somatic motor system

1. "voluntary" nervous system 2. innervates skeletal muscle From the CNS

Two main divisions of Nervous System

1. Central nervous system (CNS): - Brain and spinal cord - Integration and command center 2. Peripheral nervous system (PNS) - Paired spinal and cranial nerves carry messages to and from the CNS

What are the three types of gated membrane ion channels in a neuron?

1. Chemically gated (ligand-gated) channels—open with binding of a specific neurotransmitter 2. Voltage-gated channels—open and close in response to changes in membrane potential 3. Mechanically gated channels—open and close in response to physical deformation of receptors

What are the two main types of membrane ion channels in a neuron?

1. Leakage (nongated) channels—always open 2. Gated channels (three types)

Functions of Nervous system

1. Maintain homeostasis 2. Receiving sensory input 3. Integrating Info 4. Controlling muscles and glands 5. Est. & maintaining mental acitivity

What are the three structural classifications of Neurons?

1. Multipolar—1 axon and several dendrites (most abundant; found in both motor neurons and interneurons) 2. Bipolar—1 axon and 1 dendrite (rare, e.g., retinal neurons) 3. Unipolar (pseudounipolar)—single, short process that has two branches

Two principal cell types of Nervous Tissue

1. Neurons—excitable cells that transmit electrical signals 2. Neuroglia (glial cells): supporting cells

What are the two branches of unipolar neurons?

1. Peripheral process—more distal branch, often associated with a sensory receptor 2. Central process—branch entering the CNS

what is the difference between schwann cells and oligodendrocytes?

1. Schwann cells are in PNS, oligo are in CNS 2. one Scwann cell only produce myelin to cover a small portion of axons, one oligodendrocyte produce myelin to cover multiple axons

Two functional divisions of Peripheral Nervous System (PNS)

1. Sensory (afferent) division: - Somatic afferent fibers—convey impulses from skin, skeletal muscles, and joints - Visceral afferent fibers—convey impulses from visceral organs 2. Motor (efferent) division - Transmits impulses from the CNS to effector organs

What are the three functional classifications of Neurons?

1. Sensory (afferent): transmit impulses from sensory receptors toward the CNS 2. Motor (efferent): carry impulses from the CNS to effectors 3. Interneurons (association neurons): shuttle signals through CNS pathways; most are entirely within the CNS

Three main functions of the Nervous System

1. Sensory input: Information gathered by sensory receptors about internal and external changes [afferent] 2. Integration: Interpretation of sensory input 3. Motor output: Activation of effector organs (muscles and glands) produces a response [efferent]

Two divisions of PNS

1. Somatic (voluntary) nervous system: conscious control of skeletal muscles 2. Autonomic (involuntary) nervous system (ANS): - Visceral motor nerve fibers - Regulates smooth muscle, cardiac muscle, and glands

what are the 4 groups of spinal nerves?

1. cervical nerves 2. thoracic nerves 3. lumbar nerves 4. sacral nerves

sensory nervous system

1. contains receptors 2. transmits info from receptors to the CNS

information flow down a neuron steps

1. dendrites, cell body receive incoming signals 2. perikaryon: soma (cell body) 3. axon hillock 4. initial segment of axon (AP originates here) 5. axon 6. synaptic terminals 7. synapse 8. postsynaptic cell

function and location of microglia

1. found in CNS 2. specialized macrophages 3. respond to inflammation 4. move through tissue to phagocytize necrotic tissue, microorganisms, and foreign substances in the CNS 5. kind of like WBC's 6. maintain homeostasis of CSF and nervous tissue by repsonding to signals from other cells and remove material that affect homeostasis 7. derived from blood cells

function and location of shwann cells

1. found in PNS 2. produce myelin sheaths 3. help electrical currents flow along axons 4. help peripheral nerves regenerate 5. produce extracellular matrix around nerves 6. total axonal length covered by several of Schwann cells, and the gap between is nodes of ranvier

what is the purpose of myelin in the CNS what makes it?

1. insulator 2. increases action potential conduction velocity 3. oligodendrocytes make myelin in CNS

how is neuroglia able to communicate with multiple cells at a time?

1. intracellular waves of Ca2+ 2. intercellular diffusion of chemical messengers (like ATP)

what are the types of signals between neurons and neuroglia?

1. ion fluxes 2. neurotransmitters 3. cell adhesion molecules 4. specialized signaling molecules release from synaptic and nonsynaptic regions of neuron

ependymal cells location and function

1. line the brain 2. line the spinal cord central canal ventricles (cavities) 3. combine w/ blood vessels to form choroid plexus 4. contain cilia that beat to move CSF throughout brain, increasing efficiency of diffusion 5. their basal cell surfaces extend deep into brain and spinal cord that play similar role as astrocytes

what are the 6 types of neuroglial cells?

1. oligodendrocytes 2. astrocyes 3. ependymal cells 4. microglia 5. schwann cells 6. satellite cells

astrocytes function

1. provide supportive framework for blood vessels, neurons, and pia mater 2. limit normal permeability of capillary endothelium by secreting chemicals 3. induce blood brain barrier 4. surround synapses to regulate extracellular concentration of K+ 5. uptakes neurotransmitters 6. regulate CSF composition by regulating the levels of ions and gases

function of somatic sensory system

1. receives sensory info from skin, fascia,joints, skeletal muscle, and special senses and brings it to CNS

function of visceral sensory system

1. receives sensory info from viscera (organs) and brings it to CNS

how can neuroglia affect neuronal excitability, synaptic transmission, or coordinate activity across networks of neurons?

1. releasing neurotransmitters 2. releasing other extracellular signaling molecules

.choroid plexus

1. secretes CSF that circulate in brain and spinal cord 2. essential part in blood brain barrier because it limits the flow of solutes into the brain 3. made by combination of epithelial cells in blood vessels and ependymal cells in ventricles

What are the names of the two nervous systems in the PNS?

1. sensory nervous system 2. motor nervous system

what are the two parts of the motor nervous system in the PNS?

1. somatic motor 2. autonomic motor

what are the two parts of the sensory nervous system in the PNS?

1. somatic sensory 2. visceral sensory

function and location of satellite cells

1. surround neuronal cell bodies in ganglia OUTSIDE THE CNS 2. provide support to cell bodies 3. provide nutrients to cell bodies 4. produce blood-ganglia barrier 5. highly sensitive to injury and inflammation, important role in chronic pain

motor nervous system

1. transmits info from CNS to the rest of the body 2. sends motor information to its effectors

What is the magnitude (amplitude) of an action potential?

100 mV

Which of the following associations is incorrect? 5 sacral spinal nerves 8 cervical spinal nerves 1 coccygeal spinal nerve 11 thoracic spinal nerves 5 lumbar spinal nerves

11 thoracic spinal nerves

# of pairs of cranial nerves

12

cranial nerves & their functions

12 pair of nerves fibers; somatic fibers to skin & skeletal muscles; autonomic fibers connecting to viscera, exit at lateral edges of brainstem

# of thoracic nerves

12, spinal nerves

The two largest ventricles which begin in the L&R cerebral hemispheres & extend anteriorly & down into the cerebral hemispheres

2 lateral ventricles

What is the typical duration of a nerve action potential?

2 ms

describe bipolar neurons

2 processes- axon and dendrite, extend from opposite dies of the cell body, rare found in some special sense organs

Somatic nervous system, Autonomic nervous system

2 types of motor division

how many types of glial cells in the PNS

2- satellite cells, Schwann cells

# of pairs of spinal nerves

31

The spinal cord consists of __________ segments, each associated with two pairs of nerve roots. 12 29 to 31 5 31

31

The spinal cord consists of five regions and ________ segments. 31 25 12 5 The number varies widely among individuals.

31

The spinal cord consists of how many arguments & bilateral pairs of spinal nerves

31

spinal nerves & their functions

31 pairs of nerves; somatic fibers connecting to skin & skeletal muscle; autonomic fibers connecting to viscera

Narrow space in the midline of the brain beneath the corpus callosum, which is a bridge of axons that link the 2 cerebral hemispheres is what ventricle

3rd ventricle

Spaces and brain regions produced by the diencephalon

3rd ventricle; thalamus, hypothalamus, posterior pituitary gland & pineal gland

After age ________ the vertebral column continues to elongate, but the spinal cord itself does not. 8 18 1 12 4

4

The spinal cord stops elongating at about __________ years of age. 4 10 15 2

4

The following are the steps involved in transmission at a cholinergic synapse. 1. Chemically-gated sodium channels on the postsynaptic membrane are activated. 2. Calcium ions enter the synaptic terminal. 3. Acetylcholinesterase hydrolyzes acetylcholine. 4. An action potential depolarizes the synaptic terminal at the presynaptic membrane. 5. The synaptic terminal reabsorbs choline. 6. Acetylcholine is released from storage vesicles by exocytosis. 7. Acetylcholine binds to receptors on the postsynaptic membrane. 8. Calcium ions are removed from the cytoplasm of the synaptic terminal. The correct sequence for these events is 2, 5, 4, 6, 7, 1, 8, 3. 4, 2, 6, 7, 8, 5, 3, 1. 4, 2, 6, 7, 1, 8, 3, 5. 2, 4, 6, 7, 1, 8, 3, 5. 6, 4, 2, 7, 1, 8, 3, 5.

4, 2, 6, 7, 1, 8, 3, 5

The following are the main steps in the generation of an action potential. 1. Sodium channels are inactivated. 2. Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization. 3. Sodium channels regain their normal properties. 4. A graded depolarization brings an area of an excitable membrane to threshold. 5. A temporary hyperpolarization occurs. 6. Sodium channel activation occurs. 7. Sodium ions enter the cell and depolarization occurs. The proper sequence of these events is 4, 6, 7, 3, 2, 5, 1. 2, 4, 6, 7, 1, 3, 5. 4, 2, 5, 6, 7, 3, 1. 6, 7, 4, 1, 2, 3, 5. 4, 6, 7, 1, 2, 3, 5.

4, 6, 7, 1, 2, 3, 5

how many types of glial cells in the CNS

4- astrocytes, microglia, ependymal, oligodendrocytes

Located in the brainstem, just anterior to the cerebellum and has openings in its roof that lead to the subarachnoid space is what ventricle

4th ventricle

Spaces and brain regions produced by the metencephalon

4th ventricle; cerebellum & pons

Spaces and brain regions produced by the myelencephalon

4th ventricle; medulla oblongata

# of lumbar nerves

5, spinal nerves

# of sacral nerves

5, spinal nerves

31 pairs of spinal nerves

8 cervical, 12 thoracic, 5 lumbar, 5 sacral & 1 coccygeal

# of cervical nerves

8, spinal nerves

A second nerve impulse cannot be generated until ________. A) the membrane potential has been reestablished B) the Na ions have been pumped back into the cell C) proteins have been resynthesized D) all sodium gates are closed

A

Neuroglia that control the chemical environment around neurons by buffering potassium and recapturing neurotransmitters are ________. A) astrocytes B) oligodendrocytes C) microglia D) Schwann cells

A

Saltatory conduction is made possible by ________. A) the myelin sheath B) large nerve fibers C) diphasic impulses D) erratic transmission of nerve impulses

A

The part of a neuron that conducts impulses away from its cell body is called a(n) ________. A) axon B) dendrite C) neurolemma D) Schwann cell

A

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? A) ependymal cells B) Schwann cells C) oligodendrocytes D) astrocytes

A

Which of the choices below describes the ANS? A) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands B) motor fibers that conduct nerve impulses from the CNS to skeletal muscles C) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS D) sensory and motor neurons that supply the digestive tract

A

unmyenlienated axons of the pns

A Schwann cell surrounds nerve fibers but coiling does not take place Schwann cells partially enclose 15 or more axons

graded, action

A ___ potential will cause EITHER hyperpolarization or depolarization, while a ______ potential will cause a depolarization only.

sodium

A depolarized membrane allows ______ to flow inside the membrane

limbic system

A group of neural structures at the base of the cerebral hemispheres & structures in the diencephalon that is associated with ( emotion and motivation !!!)

Define Limbic System:

A group of structures surrounding the corpus callosum which produces various emotional feelings: fear, anger, sorrow, etc.

choroid plexus

A highly vascular tissue in the lining of the ventricles that secretes CSF (blue area)

Cl− is a common negatively charged extracellular ion. Predict the effect on the RMP if many Cl− gated channels are suddenly opened. A more negative RMP would result. There would be no change in the RMP. The membrane would become hypopolarized or have less charge separation across the membrane. The RMP would become more positive.

A more negative RMP would result.

a visceral motor neuron

A multipolar neuron that synapses on a gland cell is functionally classified as A) a visceral motor neuron B) a somatic motor neuron C) a sensory neuron D) an interneuron

node of ranvier

A myelinated axon will allow an action potential to jump from one ___ ___ ___ to another.

both a and b

A nerve impulse involves ____________ across a neuron's plasma membrane. A) changes in voltage B) movement of ions C) both a and b D) neither a nor b

Which of the following is false or incorrect?

A nerve impulse occurs if the excitatory and inhibitory effects are equal.

Define Reticular Formation:

A network of gray and white matter fibers within the brain stem that: 1) connect the superior spinal cord to all major brain parts. 2) arouse the cerebrum. 3) filter inbound sensory impulses for importance.

Which of the following is true of axons?

A neuron can have only one axon, but the axon may have occasional branches along its length.

Which of the following is true of axons? Axons use chemically gated ion channels to generate graded potentials. Neurons can have multiple axons but only one dendrite. Smaller (thinner) axons are more likely to bear myelin sheaths than larger (thicker) axons. A neuron can have only one axon, but the axon may have occasional branches along its length.

A neuron can have only one axon, but the axon may have occasional branches along its length.

voltage

A neuron generates an action potential at the trigger zone, where there is a high density of _____ gated channels.

Cranial nerves VI..primarily motor

Abducens

Are there more neurons or neuroglia cells in the CNS?

Abundantly more neuroglia than neurons in CNS

Cranial nerves XI..muscles of soft palate..trapezius & sternocleidomastoid..primarily motor

Accessory

excitatory, either

Acetycholine is ______ in the neuromuscular junction and can be ______ elsewhere in the body.

Preganglionic neurons in the sympathetic division release what

Acetylcholine

Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine?

Acetylcholine is degraded by acetylcholinesterase.

Most sympathetic postganglionic neurons secrete norepinephrine & are called

Adrenergic

sodium potassium pump

After hyperpolarization, what brings the RMP back to -70?

Active neurons need ATP to support which of the following? the movement of materials from the soma by axoplasmic transport the synthesis of neurotransmitter molecules the recovery from action potentials the movement of materials to the soma by axoplasmic transport All of the answers are correct.

All of the answers are correct.

Any stimulus that opens ________ ion channel will produce a graded potential. a voltage-gated a sodium a mechanically-gated a chemically-gated All of the answers are correct.

All of the answers are correct.

In meningitis, viruses can be the cause. bacteria can be the cause. inflammation of the meninges occurs. CSF flow can be disrupted. All of the answers are correct.

All of the answers are correct.

During propagation of the action potential, __________. local currents depolarize a spot adjacent to the active zone after threshold is reached, sodium channels open rapidly the axon hillock depolarizes the initial segment All of these events occur during propagation of the action potential.

All of these events occur during propagation of the action potential.

The effect of a nerve impulse on a postsynaptic neuron depends on the __________. kind of neurotransmitter released by the presynaptic neuron quantity of neurotransmitter released characteristics of the receptor on the postsynaptic neuron All of these factors affect what happens at the postsynaptic neuron.

All of these factors affect what happens at the postsynaptic neuron.

Which processes are always part of a reflex arc? receptor activation afferent action potential efferent action potential All of these processes are part of every reflex arc.

All of these processes are part of every reflex arc.

The two major types of adrenergic receptors are

Alpha & beta

ependymal cells; epithelial cells

Although classified as glial cells, ____________ are also ____________ that line the cavities in the brain and spinal cord and help form the choroid plexus. A) astrocytes; phagocytes B) microglia; phagocytes C) ependymal cells; epithelial cells D) oligodendrocytes; epithelial cells

neurons; glial cells

Although they outnumber ____________ by as much as ten to one, ____________ account for only about half of the total volume of the nervous system. A) neuroglia; neurons B) neurons; glial cells C) interneurons; sensory neurons D) astrocytes; oligodendrocytes

glutamate, gaba, glycine

Amino acid neurotransmitters include what three main types?

Which of the following occurs first? An action potential arrives at the axon terminal. Synaptic vesicles exit by exocytosis. Voltage-gated calcium channels are opened. Extracellular calcium enters the axon terminal.

An action potential arrives at the axon terminal.

What conditions will increase the diffusion of molecules, such as neurotransmitters? An increase in the distance between the neurons. An increased viscosity of the fluid between neurons. An increase in number of postsynaptic receptors. An increase in the amount of neurotransmitter exocytized by the presynaptic axon.

An increase in the amount of neurotransmitter exocytized by the presynaptic axon.

How is an action potential propagated along an axon? Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon. An efflux of potassium from the current action potential depolarizes the adjacent area. An influx of sodium ions from the current action potential depolarizes the adjacent area

An influx of sodium ions from the current action potential depolarizes the adjacent area

How is an action potential propagated along an axon?

An influx of sodium ions from the current action potential depolarizes the adjacent area.

________ neurons are small and have no anatomical features that distinguish dendrites from axons. Sensory Bipolar Unipolar Multipolar Anaxonic

Anaxonic

thirst center

Angiotensin II stimulates the ____ _____.

What are some places an axon terminal can connect?

Another nerve cell (dendrites) A muscle or gland

The gray matter of the spinal cord divides the white matter of the spinal cord into 3 regions on each side called the

Anterior, lateral & posterior funiculi

CSF is continuously reabsorbed into the blood through tiny, finger-like projections called

Arachnoid granulations

Thin weblike membrane that does not have blood vessels and is located btwn the dura and pia mater

Arachnoid mater

Removal of neurotransmitters occurs when they:

Are degraded by enzymes Are reabsorbed by astrocytes or the presynaptic terminals Diffuse from the synaptic cleft

Nerve fibers

Arm-like extensions from the soma There are two types: axons (carry impulses away from the soma) and dendrites (carry impulses toward the soma) Bundles of fibers are called tracts in the CNS and nerves in the PNS

The process of linking new facts with old facts already stored in the memory bank is called ________. long-term memory automatic memory Association rehearsal

Association

Unconscious activity is what division of the PNS

Autonomic NS

Supply's muscles & skin of the anterior, lateral & posterior regions of the arm

Axillary nerves

List and describe different types of synapses

Axodendritic—between the axon of one neuron and the dendrite of another Axosomatic—between the axon of one neuron and the soma of another Less common types: - Axoaxonic (axon to axon) - Dendrodendritic (dendrite to dendrite) - Dendrosomatic (dendrite to soma)

axodendritic synapse

Axon terminal of presynaptic neuron terminates on dendrites or cell body of postsynaptic neuron (e.g. many synapses of PNS).

An impulse from one nerve cell is communicated to another nerve cell via the ________. A) cell body B) synapse C) receptor D) effector

B

An inhibitory postsynaptic potential (IPSP) is associated with ________. A) a change in sodium ion permeability B) hyperpolarization C) opening of voltage-regulated channels D) lowering the threshold for an action potential to occur

B

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________. A) positively charged and contains less sodium B) negatively charged and contains less sodium C) negatively charged and contains more sodium D) positively charged and contains more sodium

B

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? A) mechanically gated channel B) voltage-gated channel C) leakage channel D) ligand-gated channel

B

An example of the brain affecting spinal reflexes is the replacement of the __________ by the __________. Babinski sign; plantar reflex plantar reflex; Babinski sign Babinski sign; flexor reflex flexor reflex; plantar reflex

Babinski sign; plantar reflex

Where is the Hypothalamus located?

Beneath the thalamus. It forms the floor of the 3rd ventricle.

catecholamines, indolamines

Biogenetic Amines are neurotransmitters that contain which two main groups?

Describe a Neuron Cell Body

Biosynthetic center of a neuron Spherical nucleus with nucleolus Well-developed Golgi apparatus Rough ER = Nissl bodies (chromatophilic substance) Network of neurofibrils (neurofilaments) Axon hillock—cone-shaped area from which axon arises

________ neurons are short, with a cell body between dendrite and axon, and occur in special sense organs. Multipolar Unipolar Motor Bipolar Anaxonic

Bipolar

What is the difference between a suclus and a fissure?

Both are grooves. Fissures are deep. Sulci are shallow.

Which of the following is true of adrenergic receptors?

Both epinephrine and norepinephrine are coupled to a G protein

axons of the cns

Both myelinated and unmyelinated fibers are present Myelin sheaths are formed by oligodendrocytes Nodes of Ranvier are widely spaced There is no neurilemma

The structures labeled "1" are dendrites. Their membranes contain numerous chemically-gated ion channels. The first statement is false but the second statement is true. Both statements are true. The first statement is true but the second statement is false. Both statements are false. Both statements are true and relate to synaptic transmission.

Both statements are true and relate to synaptic transmission.

What is another name for the synaptic knobs of axon terminals?

Boutons

Plexus of nerves to the muscles & skin of the upper limbs formed btwn C5-T1

Brachial plexus

Central Nervous System

Brain and spinal cord Integration and command center

Centers for control of the SANS & PANS are primarily located where

Brain stem

Connects the brain to the spinal cord & consists of the midbrain, pons & the medulla oblongata

Brainstem

The preganglionic fibers of the parasympathetic division arise from neurons in the

Brainstem & S2-4 region of the spinal cord

Describe the structure and function of Oligodendrocytes

Branched cells Processes wrap CNS nerve fibers [jelly roll], forming insulating myelin sheaths (once wrapped) Function: insulation

What is the difference between nerves and tracts?

Bundles of neuron processes are called tracts in the CNS and nerves in the PNS.

What are bundles of neural processes called in the CNS? In the PNS?

Bundles of processes are called: Tracts in the CNS Nerves in the PNS

A neuron that has as its primary function the job of connecting other neurons is called a(n) ________. A) efferent neuron B) afferent neuron C) association neuron D) glial cell

C

Collections of nerve cell bodies outside the central nervous system are called ________. A) nuclei B) nerves C) ganglia D) tracts

C

If a motor neuron in the body were stimulated by an electrode placed about midpoint along the length of the axon ________. A) the impulse would move to the axon terminal only B) muscle contraction would occur C) the impulse would spread bidirectionally D) the impulse would move to the axon terminal only, and the muscle contraction would occur

C

Schwann cells are functionally similar to ________. A) ependymal cells B) microglia C) oligodendrocytes D) astrocytes

C

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. A) ion B) cholinesterase C) neurotransmitter D) biogenic amine

C

The term central nervous system refers to the ________. A) peripheral and spinal nerves B) brain, spinal cord, and peripheral nerves C) brain and spinal cord D) spinal cord and spinal nerves

C

What does the central nervous system use to determine the strength of a stimulus? A) origin of the stimulus B) type of stimulus receptor C) frequency of action potentials D) size of action potentials

C

What is the role of acetylcholinesterase? A) act as a transmitting agent B) amplify or enhance the effect of ACh C) destroy ACh a brief period after its release by the axon endings D) stimulate the production of acetylcholine

C

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? A) cholinesterase B) norepinephrine C) acetylcholine D) gamma aminobutyric acid

C

Which of the following is not characteristic of neurons? A) They conduct impulses. B) They have extreme longevity. C) They are mitotic. D) They have an exceptionally high metabolic rate.

C

Which of the following is not true of graded potentials? A) They are short-lived. B) They can form on receptor endings. C) They increase amplitude as they move away from the stimulus point. D) They can be called postsynaptic potentials.

C

Which of the following is true about the movement of ions across excitable living membranes? A) Ions always move actively across membranes through leakage channels. B) Ions always move passively across membranes. C) Sodium gates in the membrane can open in response to electrical potential changes. D) Ions always move from an area of higher concentration to an area of lower concentration

C

Which fibers generate the smallest value for conduction velocity?

C Fibers

Which fibers generate the smallest value for conduction velocity?

C fibers

Central Nervous System

CNS

The neural tube of the embryonic brain gave rise to the

CNS

Functions as nutritive & protective..helps maintain a stable ionic concentration in the CNS..provides a pathway to the blood for waste

CSF

Ventricles are continuous with the central canal of the spinal cord and contain what fluid

CSF

What is the role of calcium in synaptic activity?

Calcium influx into the synaptic terminal causes vesicle fusion.

Based on your knowledge of action potentials in neurons, what can you conclude about how they occur in cardiac muscle fibers?

Cardiac muscle fibers depolarize more quickly and spend more time depolarized than neurons do.

Motor (efferent ) neurons

Carry impulse from the central system to the PMS

Sensory (afferent) neurons

Carry impulses from the sensory receptors to the CNS (found in Cutaneous Sense Organs)

ne, epinephrine, da

Catecholamines contains which three neurotransmitters?

Nerves that descend from the bottom of the spinal cord are called

Cauda equina

The filum terminale and the spinal nerves below the conus medullaris form a structure that resembles a horses' tail is called what

Cauda equina

3 basal ganglia's

Caudate nucleus, putamen & globus pallidus

What is a Perikaryon or Soma?

Cell Body of a Neuron

What are clusters of cell bodies called in the CNS? In the PNS?

Clusters of cell bodies are called: 1. Nuclei in the CNS (not to be confused with organelle) 2. Ganglia in the PNS

cauda equina

Collection of spinal nerves below the end of the spinal cord

Which statement about coma is true? Coma may be caused by widespread cerebral or brain stem trauma. Coma is neurologically identical to syncope. During coma, brain oxygen consumption resembles that of a waking state. Coma is a form of deep sleep.

Coma may be caused by widespread cerebral or brain stem trauma.

Combined Summation

Combined spatial and temporal summation

What causes membrane potential changes?

Concentrations of ions across the membrane change Permeability of membrane to ions changes

What is the general function of an axon?

Conducting region of a neuron Generates and transmits nerve impulses (action potentials) away from the cell body [efferent] Molecules and organelles are moved along axon by motor molecules both toward the axon terminal and toward the cell body

Conduction velocities of axons

Conduction velocities vary widely among neurons Rate of impulse propagation is determined by: Axon diameter - the larger the diameter, the faster the impulse Presence of a myelin sheath - myelination dramatically increases impulse speed Presence and frequency of nodes of Ranvier which result in saltatory conduction

conus medullaris

Cone-shaped ending of the spinal cord. in the lumbar area

cerebellum

Controls posture, balance and coordinates complex movements ( o )

Structure that is inferior to the lumbar enlargement where the spinal cord tapers off and becomes the nerves of the remaining lumbar and sacral levels is called what

Conus medullaris

2 pair of rounded knobs on the superior surface of the midbrain mark the location of 4 nuclei known collectively as

Corpora quadrigemina

Broad, flat bundles of axons that connect the hemispheres of the cerebrum

Corpus callosum

PNS include what two types of nerves

Cranial & spinal

When flexor muscles on the the affected side contract the flexor muscles of the limb in the other side are inhibited is called what type of reflex

Crossed extensor reflex

decussation

Crossing-over of some nerve tracts in the CNS; occurs with ascending & descending nerve tracts

Salatory conduction

Current passes through a myelinated axon only at the nodes of Ranvier Voltage-gated Na+ channels are concentrated at these nodes Action potentials are triggered only at the nodes and jump from one node to the next Much faster than conduction along unmyelinated axons

14) Which of the following is not a function of the autonomic nervous system? A) innervation of smooth muscle of the digestive tract B) innervation of cardiac muscle C) innervation of glands D) innervation of skeletal muscle

D

Immediately after an action potential has peaked, which cellular gates open? A) sodium B) chloride C) calcium D) potassium

D

Nerve cell adhesion molecules (N-CAMs) ________. A) release nerve growth factor B) are found on "pathfinder" neurons C) are crucial in the production of neurotransmitters D) are crucial for the development of neural connections

D

Select the correct statement regarding synapses. A) Cells with gap junctions use chemical synapses. B) The release of neurotransmitter molecules gives cells the property of being electrically coupled. C) Neurotransmitter receptors are located on the axons terminals of cells. D) The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.

D

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. A) resting period B) repolarization C) depolarization D) absolute refractory period

D

When a sensory neuron is excited by some form of energy, the resulting graded potential is called a(n) ________. A) postsynaptic potential B) excitatory potential C) action potential D) generator potential

D

Which of the following will occur when an excitatory postsynaptic potential (EPSP) is being generated on the dendritic membrane? A) Specific sodium gates will open. B) Specific potassium gates will open. C) Sodium gates will open first, then close as potassium gates open. D) A single type of channel will open, permitting simultaneous flow of sodium and potassium.

D

dopamine

DA AKA

Which of the following statements is a false or incorrect statement? Damage to the primary motor cortex results only in the loss of both voluntary muscle control and reflexes. Damage to the premotor cortex results in loss of motor skills programmed in that area but movement is still possible. Damage to the primary auditory cortex results in the inability to interpret pitch, loudness, and location. Damage to the primary visual cortex results in functional blindness.

Damage to the primary motor cortex results only in the loss of both voluntary muscle control and reflexes.

Way of mapping the sensory information of the different spinal nerves

Dermatomes

Two grooves that extend the length of the spinal cord, dividing it into R&L halves are the

Deep anterior median fissure & shallow posterior median sulcus

What are three ways to terminate a neurostransmitter effect?

Degradation by enzymes Reuptake by astrocytes or axon terminal Diffusion away from the synaptic cleft

What are the two kinds of processes found in a neuron?

Dendrites and axons

na+

Density of voltage-gated ____ channels is greater at the trigger zone during summation.

Largest & most important deep nuclei within he cerebellum is the

Dentate nucleus

Develops from the posterior forebrain & is located btwn the cerebral hemispheres & superior to the brainstem.. Surrounds the 3rd ventricle & is largely composed of gray matter

Diencephalon

Optic tracts, optic chiasma, infundibulum, posterior pituitary gland, mammillary bodies & pineal gland are located within the

Diencephalon

Posterior portion of the prosencephalon

Diencephalon

reflex arc

Direct route from a stimulated sensory neuron, to an interneuron, to a motor neuron, (only a couple of neurons are involved)

Neurotransmitter Receptor Mechanisms

Direct: neurotransmitters that open ion channels Promote rapid responses Examples: ACh and amino acids Indirect: neurotransmitters that act through second messengers Promote long-lasting effects Examples: biogenic amines, peptides, and dissolved gases

Types of Circuits in Neuronal Pools

Divergent - one incoming fiber stimulates ever increasing number of fibers, often amplifying circuits Convergent - opposite of divergent circuits, resulting in either strong stimulation or inhibition Reverberating - chain of neurons containing collateral synapses with previous neurons in the chain Parallel after-discharge - incoming neurons stimulate several neurons in parallel arrays

yes

Does the action potential have a refractory period?

yes

Does the action potential propagate?

no

Does the graded potential have a refractory period?

no

Does the graded potential propagate?

Neurotransmitter used by the basal ganglia's

Dopamine

Nerve fibers enter & exit the spinal cord via 3 roots

Dorsal(sensory), dorsal ganglion(cell bodies) & ventral(motor)

some, reset

During hyperpolarization, ___ K+ channels remain open and Na+ channels ____.

Falx cerebelli, falx cerebri & tentorium cerebelli are the three partitions of what layer of meninges

Dura mater

Forms strong tubular sheath to protect the spinal cord and ends at the 2 sacral vertebra..it is separated from the vertebrae by epidural space

Dura mater

Forms the internal periosteum of the skull..splits into 2 layers forming channels called dural & venous sinuses

Dura mater

Outermost layer of meninges composed of tough, white, dense connective tissue and contains many blood vessels

Dura mater

3 layers of meninges

Dura, arachnoid & pia mater

falx cerebri

Dural Septa separating the cerebral hemispheres

crosses over

During an electrical synapse there is a continuous flow among the membrane of electrical stimulus. This ____ ____ to the other cell.

hyperpolarizing

During an inhibitory effect the neurotransmitter released by presynaptic cell binds to the postsynaptic cell receptors and has a _________ effect.

neuron

During both presynaptic facilitation and presynaptic inhibition another ______ steps in and helps regulate the activity of the presynaptic cell.

gap , propagates

ELECTRICAL SYNAPSE STEP FIVE: An ionic current flows through a ___ junction and stimulates the production of an action potential in the adjacent cardiac muscle cell. Thus, the action potential _____ to the adjacent cell.

action potential, propagates

ELECTRICAL SYNAPSE STEP FOUR: An ionic current stimulates the production of another _____ _____. Thus, the aciton potential ______ along the plasma membrane.

electrical

ELECTRICAL SYNAPSE STEP ONE: ______ Synapses connect cardio muscle cells.

ionic

ELECTRICAL SYNAPSE STEP THREE: An action potential in the plasma membrane generates _____ currents that flow to adjacent parts of the plasma membrane and through the gap junctions.

gap, connexons

ELECTRICAL SYNAPSE STEP TWO: An electrical synapse has ___ junctions in which the membranes of two cells are separated by a gap but are connected by proteins called ______.

The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron? IPSPs EPSPs neither IPSPs nor EPSPs both IPSPs and EPSPs

EPSPs

EPSPs are ___________. graded EPSPs have all of these characteristics. excitatory postsynaptic

EPSPs have all of these characteristics.

Structure of an axon

Each neuron has a single slender axon of uniform diameter arising from the axon hillock. Axons may occasionally branch along their length prior to reaching the axonal terminus. These 90 degree branches, if present, are called axon collaterals. Axonal terminal - the profusely branched terminus of an axon.

Which of the following is NOT true of efferent neurons?

Efferent neurons are bipolar

Which of the following interactions between electrical and chemical gradients does not lead to the establishment of a neuron's resting potential? Potassium ions are repulsed by positive charges outside the cell. Chemical forces tend to drive potassium ions out of the cell. Potassium ions are attracted to the negative charges inside the cell. Electrical forces push sodium ions out of the cell. Chemical and electrical forces both favor sodium ions entering the cell.

Electrical forces push sodium ions out of the cell.

Nerve Impulses are:

Electrical impulses carried along the length of axons Always the same regardless of stimulus The underlying functional feature of the nervous system

Surrounds the fibers of the peripheral nerves

Endoneurium

________ line the brain ventricles and spinal canal. Oligodendrocytes Astrocytes Microglia Satellite cells Ependymal cells

Ependymal cells

adrenaline

Epinephrine AKA

Dense, fibrous, outermost layer of CT in peripheral nerves

Epineurium

Somatic=

Everything else

Operation of voltage gated channels

Example: Na+ channel Closed when the intracellular environment is negative Open when the intracellular environment is positive Voltage-gated K+ channels function the same way

Operation of a Chemically Gated Channel

Example: Na+-K+ chemically gated channel Closed when a neurotransmitter is not bound to the extracellular receptor Open when a neurotransmitter is attached to the receptor

epsp

Excitatory Postsynaptic Potentials AKA

Cranial nerves VII..facial expression..tear/salivary glands..2/3 of tongue..mixed

Facial

The cerebellum consists of 2 lateral hemispheres separated by a layer of dura mater called the

Fall cereblli

Because many of the same cardiac cells are innervated by both parasympathetic and sympathetic fibers, the influence of the two divisions on the heart is synergistic. T/F

False

Synaptic cleft

Fluid-filled space separating the presynaptic and postsynaptic neurons Prevents nerve impulses from directly passing from one neuron to the next Transmission across the synaptic cleft: Is a chemical event (as opposed to an electrical one) Ensures one-way communication between neurons

ligand

For a chemical synapse, postsynaptic membrane receptors are usually regulated by ______ gated ion channels.

temporal

For graded potentials: Summation occuring from the graded potential that results when 2 or more APs arrive at a single synapse in rapid succession.

spatial

For graded potentials: Summation occuring when 2 or more APs arrive simultaneously at 2 or more presynaptic terminals that synapse with a single neuron.

The spinal cord originates where the nervous tissue leaves the cranial cavity a the level of the what

Foramen magnum

Myelin Sheath and Neurilemma: Formation

Formed by Schwann cells in the PNS only around axons A Schwann cell forms the Myelin Sheath: Envelopes an axon in a trough Encloses the axon with its plasma membrane Forms concentric inner layers of membrane locked together with special membrane proteins that make up the myelin sheath Neurilemma is the remaining nucleus and cytoplasm of a Schwann cell occupying the outer layer.

How are Myelin Sheaths in the CNS different from those in the PNS?

Formed by processes of oligodendrocytes, not the whole cells Nodes of Ranvier are present No neurilemma Thinnest fibers are unmyelinated

Visceral pain, nausea, information about stretch, pressure (bariorecption), chemical stimuli (chemoreception)

GVA

The 5 lobes of the cerebral hemisphere are the

Frontal lobe, parietal lobe, temporal lobe, occipital lobe & the insula

Controls & coordinates skeletal muscles & helps maintain posture

Functions of the cerebellum

Interpreting sensory info, initiating voluntary muscle activity, storing memory, retrieving memory & helps to determine intelligence & personality

Functions of the cerebrum

Motor impulses for voluntary movements

Functions of the corticospinal tracts

Sensations of touch, pressure & body movement

Functions of the fasciculus

Association areas carry on higher intellectual processes for concentrating, planning, complex problem solving & judging the consequences of behavior..motor areas control movements of voluntary skeletal muscles

Functions of the frontal lobes

Sensory areas are responsible for vision..association areas combine visual images with other sensory experiences

Functions of the occipital lobes

Sensory areas provide sensations of temperature, touch, pressure & pain involving the skin..association areas function in understanding speech & in using words to express thoughts & feelings

Functions of the parietal lobes

Control muscle tone & sweat gland activity

Functions of the reticulospinal tracts

Posture control & muscle coordination

Functions of the rubrospinal tracts

Muscle sensory information & coordination of muscles

Functions of the spinocerebellar tracts

Sensations of pain, temperature, touch & pressure

Functions of the spinothalmic tracts

Sensory areas are responsible for hearing..association areas interpret sensory experiences & remember visual scenes, music & other complex sensory patterns

Functions of the temporal lobes

Which of the following is true of G protein activation?

G protein activation occurs in response to all neurotransmitters within the peripheral nervous system except for nicotinic receptors

inhibitory

GABA is _____ in the CNS.

Consciously perceived sensory information

GSA

DO NOT originate in smooth muscle, cardiac muscle, or endocrine glands

GSA

Localized sensations

GSA

Pain, vibration, pressure, temperature, stretch, proprioceptive information back to CNS

GSA

Sensory neurons with cell bodies loacted in dorsal/posterior root ganglion

GSA

Sensory receptors located in skin, skeletal muscle, bone/ligament/tendons, special sense organs

GSA

Special senses like sight, smell, balance, taste, smell

GSA

Carry efferent outflow to skeletal muscle fibers and make the muscles contract

GSE

Motor nuerons with cell bodies located in ventral/anterior horn of spinal cord or anterior regions of brainstem

GSE

Somatic Motor Neurons

GSE

Voluntary Motor system

GSE

Visceral sensory neurons

GVA

Collections of nerve cell bodies outside the central nervous system are called ________.

Ganglia

Nodes of Ranvier

Gaps in the myelin sheath between adjacent Schwann cells They are the sites where axon collaterals can emerge They function to speed up transmission of nerve impulses

Function of an axon

Generate and transmit action potentials away from the soma Secrete neurotransmitters from the axonal terminals All substances needed for axonal activity must be transported down the axon by vesicular trafficking (involves molecular motors and microtubules) Movement along axons occurs in two ways Anterograde — toward axonal terminal Retrograde — away from axonal terminal

Potentials that are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized are called ________ potentials.

Graded

What are the two types of membrane potential changes that act as signals:

Graded potentials: incoming short-distance signals (depolarizations or hyperpolarizations) Action potentials: long-distance signals of axons (occurs in muscle cells and axons of neurons)

The horizontal bar of gray matter that is in the middle of the spinal cord that connects the wings of the gray matter on the R&L sides is called the

Gray commissure

Pat axons leaving the paravertebral ganglia pass through branches called

Gray rami

Neurotransmitters: Biogenic Amines

Include: Catecholamines - dopamine, norepinephrine (NE), and epinephrine Indolamines - serotonin and histamine Broadly distributed in the brain Play roles in emotional behaviors and our biological clock

Astrocytes

Highly branched glial cells Most abundant CNS glia They cling to neurons and their synaptic endings, and cover capillaries Astrocytes Functionally, they: Support and brace neurons Anchor neurons to their nutrient supplies Guide migration of young neurons Control the chemical environment New evidence suggests they may effect integration

myelin sheath

Impulses travel faster when fibers have a _____

myelinated

In a ____ axon, this keeps current in axons.

dendrite ends

In a bare plasma membrane, one with out voltage gated channels, voltage decays because current leaks across the membrane, and seaps through the ____ ___ as an example.

continuous conduction

In an unmyelinated axon, in which the voltage gated Na+ and K+ channels regenerate action potentials at each point along the axon, so voltage does not decay. Conduction is SLOWER because movements of ions and of the gates of channel proteins take tie and must occur before voltage regeneration occurs.

What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?

In facilitated diffusion, molecules only move with the aid of a protein in the membrane.

Dendrites

In motor neurons they are short, tapering, and diffusely branched processes but do take other forms in other neurons. They are the main receptive, or input, regions of the neuron. Electrical signals travel as graded potentials (not action potentials) toward the soma over dendritic fibers.

Which of the following is a difference between primary and secondary active transport?

In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated.

continuous, saltatory

In terms of nerve impulse conduction, unmyelinated is to ____________ as myelinated is to ____________. A) oligodendrocytes; neurolemmocytes B) neurolemmocytes; oligodendrocytes C) continuous; saltatory D) saltatory; continuous

Neurotransmitters: Amino Acids

Include: GABA - Gamma ()-aminobutyric acid Glycine Aspartate Glutamate Found only in the CNS

Neurotransmitters: Peptides

Include: Substance P - mediator of pain signals Beta endorphin, dynorphin, and enkephalins Act as natural opiates; reduce pain perception Bind to the same receptors as opiates and morphine Gut-brain peptides - somatostatin, and cholecystokinin

What changes occur to voltage-gated Na+ and K+ channels at the peak of depolarization?

Inactivation gates of voltage-gated Na+ channels close, while activation gates of voltage-gated K+ channels open.

serotonin, histamine

Indolamines contain which two main neurotransmitters?

Lower masses of the corpora quadrigemina which contain the centers for certain auditory reflexes

Inferior colliculi

ipsp

Inhibitory Postsynaptic Potentials AKA

inhibitory postsynaptic potential

Inhibitory effect on downstream cell AKA

What component of the reflex arc determines the response to a stimulus?

Integration Center

What is the electrical "resting" state of a neuron?

Inside the cell is more negative; outside the cell is more positive.

Central branches of the thoracic spinal nerves do not enter a plexus, instead, they extend into spaces btwn the ribs as

Intercostal nerves

________ are the most numerous type of neuron in the CNS. Bipolar neurons Motor neurons Unipolar neurons Sensory neurons Interneurons

Interneurons

visual area

Interprets activity in visual cortex, found in occipital lobe (green)

What are Basal Ganglia and where are they found?

Islands of gray matter found deep inside the white matter of each cerebral hemisphere.

Which of these are not properties of the stretch reflex? It is activated by muscle elongation. Its receptor is muscle spindle. It is a disynaptic reflex. It regulates muscle length.

It is a disynaptic reflex.

threshold

It is called a stimulatory effect because the event brings the postsynaptic cell closer to _____.

What ion causes repolarization of the neuron during an action potential?

K+ (potassium)

During the hyperpolarization phase of the action potential, when the membrane potential is more negative than the resting membrane potential, what happens to voltage-gated ion channels?

K+ channels close. Na+ channels go from an inactivated state to a closed state.

Which of the following is the clearest example of a neuronal membrane's selective permeability?

K+ ions can diffuse across the membrane more easily than Na+ ions.

During an action potential, hyperpolarization beyond (more negative to) the resting membrane potential is primarily due to __________.

K+ ions diffusing through voltage-gated channels

The repolarization phase of the action potential, where voltage becomes more negative after the +30mV peak, is caused primarily by __________.

K+ ions leaving the cell through voltage-gated channels

The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.

K+; Na+

pituitary gland

Known as the "Master Gland" it controls the hormone production of other glands; located at the base of the brain ( m )

In an adult, the conus medullaris is found at about L1. C1. L5. T10. T6.

L1.

What is Aphasia?

Language defects

cerebral peduncles *** not on test #12

Large fiber bundles located on the anterior surface of the midbrain. *** not on test #12

The 3 major descending tracts which conduct motor impulses from the brain are

Lateral & anterior corticospinal tracts, lateral anterior & medial reticulospinal tracts, rubrospinal tracts

Location of the corticospinal tracts, spinothalmic tracts & reticulospinal tracts

Lateral & anterior funiculi

Location of the spinocerebellar tracts & rubrospinal tracts

Lateral funiculi

Sometimes a protrusion of gray matter exists and is called the

Lateral horn

In the sympathetic division the preganglionic fibers originate from neurons in the

Lateral horn of the spinal cord

Spaces and brain regions produced by the telencephalon

Lateral ventricles; cerebrum & basal nuclei

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?

Leak channels

Controls emotional experience & expression & can modify the way a person acts

Limbic system

Frontal & temporal bones connect with the thalamus, hypothalamus, basal nuclei & other deep nuclei to form the

Limbic system

Silvia divides each hemisphere into

Lobes

Thickening of the spinal cord in the lower back region that supplies nerves to the lower limbs is called what

Lumbar enlargement

Plexus of nerves to supply the lower abdomen, pelvis & lower ribs formed btwn T12-S5

Lumbosacral plexus

Supply's muscles of the forearms & muscles & skin of the hands

Median nerves

An enlarged continuation of the spinal cord which extends from the level of the foramen magnum to the pons

Medulla oblongata

Composed of tracts for information btwn the brain & the spinal cord

Medulla oblongata

The cardiac center, which increases/decreases heart rate, the vasomotor center, which contract the walls of blood vessels & the respiratory center, which maintains the basic rhythm of breathing are all located within the

Medulla oblongata

What are spinal nerves and how many does a human have?

Mixed nerves originating from spinal cord. 31 spinal nerves.

Which of the following is NOT true of association neurons?

Most association neurons are confined within the peripheral nervous system (PNS).

Which of the following is NOT true of association neurons? Association neurons account for over 99% of the neurons in the body. Most association neurons are confined within the peripheral nervous system (PNS). Association neurons are also known as interneurons. Most association neurons are multipolar.

Most association neurons are confined within the peripheral nervous system (PNS).

How are Autonomic Activities controlled?

Mostly under influence of brain and spinal cord. - Vital centers in Medulla react to stimuli from viscera. Send out motor impulses on autonomic nerves. - Hypothalamus regulates various homeostatic processes by influencing autonomic pathways. - Limbic system and cerebral cortex use autonomic pathways to regulate emotional expression and behavior.

Descending tracts that conduct efferent impulses from the brain are also called

Motor

Efferent=

Motor

Neuron Classification Structural

Multipolar — three or more processes Bipolar — two processes (axon and dendrite) Unipolar — single, short process

Structural classification of neurons

Multipolar: most neurons in CNS Bipolar: sensory in retina of the eye and nose Unipolar: single process that divides into two branches. Part that extends to the periphery has dendrite-like sensory receptors

Acetylcholine can combine with 2 types of cholinergic receptors called

Muscarinic & nicotinic receptors

Supply's muscles of the arm on the anterior side & the skin of the forearms

Musculocutaneous nerves

Posterior portion of the rhombencephalon

Myelencephalon

Describe Multiple Sclerosis

Myelin sheaths around axons wear away and axons are scleroted Signal is slowed or even stopped Pg. 405 in textbook

In which type of axon will velocity of action potential conduction be the fastest?

Myelinated axons with the largest diameter

reuptake

NEUROTRANSMITTER TERMINATION: ______ by astrocytes or the presynaptic terminal, where the neurotransmitter is stored or destroyed by enzymes, as with norepinephrine.

degradation

NEUROTRANSMITTER TERMINATION: _______ by enzymes associated with the postsynaptic membrane or present in the synapse, as with acetycholine.

The diffusion of what ion, across the neuronal membrane, is responsible for the local currents that depolarize regions of the axon to threshold? `

Na+

Which of the following is most likely to move through the cell membrane by facilitated diffusion?

Na+

The concentrations of which two ions are highest outside the cell.

Na+ and Cl-

During the action potential of a neuron, which ion is primarily crossing the membrane during the depolarization phase, and in which direction is the ion moving?

Na+ is entering the cell.

The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped?

Na+ is pumped out of the cell and K+ is pumped into the cell.

What ion is responsible for the depolarization of the neuron during an action potential?

Na+ sodium

What prevents the Na+ and K+ gradients from dissipating?

Na+-K+ ATPase

These ion concentrations are a result of two processes

Na/k pump and membrane permeability

Motor (efferent) division

Nerve fibers that carry impulses away from the central nervous system

Sensory afferent division

Nerve fibers that carry information to the central nervous system

Synaptic cleft information transfer

Nerve impulses reach the axonal terminal and open Ca2+ channels Neurotransmitter is released into the synaptic cleft via exocytosis Neurotransmitter crosses the cleft and binds to receptors Ion channels open, causing an excitatory or inhibitory effect Synaptic Cleft: Information Transfer Termination of Neurotransmitter Effects Neurotransmitter bound to a postsynaptic neuron: Produces a continuous postsynaptic effect Blocks reception of additional "messages" Must be removed from its receptor

What are Choroid Plexuses?

Networks of capillaries that project from the Pia Mater into the Lateral (1st & 2nd) ventricles and into the roofs of the 3rd & 4th ventricles.

The two principal cell types of the nervous system are:

Neurons (10%) - excitable cells that transmit nerve impulses and perform integration Supporting cells (90%) - Called neuroglia or glial cells these cells surround and wrap neurons to perform tasks necessary for neuronal functioning.

Describe ELECTRICAL synapses

Neurons are electrically coupled (joined by gap junctions) Communication is very rapid, and may be unidirectional or bidirectional Are important in: - Embryonic nervous tissue - Some brain regions, eyes [Less common than chemical synapses]

Which of the following is NOT a characteristic of neurons?

Neurons are relatively small, simple-structured cells.

chemical synapse

Neurotransmission is mediated via release of chemical messengers from presynaptic cell that cross synaptic cleft and bind receptors on postsynaptic cell.

Clusters of RER and free ribosomes in neurons are called perikaryon. neurofibrils. microglia. Nissl bodies. neurofilaments.

Nissl bodies.

Electicical Synapses

No Neurotransmitters Are less common than chemical synapses Correspond to gap junctions found in other cell types Are important in the CNS in: Arousal from sleep Mental attention Emotions and memory Ion and water homeostasis

All-or-none principle

No matter how strong the stimulus, as long as it is greater than threshold, then action potential will occur.

A gap between Schwann cells in the peripheral system is called a(n) ________.

Node of Ranvier

What are the Myelin sheath gaps between adjacent Schwann cells called?

Nodes of Ranvier [These are sites where axon collaterals can emerge]

Postganglionic neurons in the sympathetic division release what

Norepinephrine & epinephrine

What is the difference between the clusters of cell bodies called nuclei and those known as ganglia?

Nuclei exist in the CNS, ganglia in the PNS.

Supply's the adductor muscles of the thighs

Obturator nerves

Cranial nerves III..eye movements..primarily motor

Occulomotor

Cranial nerves I..sense of smell..sensory

Olfactory

The 12 pairs of cranial nerves..(oh oh oh to touch and feel very good velvet ah ha..I II III IV V VI VII VIII IX X XI XII)

Olfactory, optic, occulomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory & hypoglossal

insensitive

Once activation gate is opened; A timer starts and when it is up, the ____ gate closes.

same

Once the insensitive channel is shut; it will always reset after the __ amount of time.

What characterizes repolarization, the second phase of the action potential?

Once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV.

Describe the structure of an Axon

One axon per cell arising from the axon hillock Long axons (nerve fibers) Occasional branches (axon collaterals) Numerous terminal branches (telodendria) Knoblike axon terminals (synaptic knobs or boutons)

What effect did decreasing the extracellular sodium have on the resting membrane potential?

Only a small change occurred, because the resting neuron is not very permeable to sodium.

Cranial nerves II..sense of vision..sensory

Optic

Visceral=

Organs

Nerves that branch out from the CNS are what

PNS

Peripheral nervous system

PNS

In a spinal reflex, information flows from __________ to __________ to __________. PNS; PNS; CNS CNS; CNS; PNS PNS; CNS; PNS CNS; PNS; CNS

PNS; CNS; PNS

Peripheal Nervous System

Paired spinal and cranial nerves Carries messages to and from the spinal cord and brain): Two Functional Divisions Sensory (afferent) division Sensory fibers - carry impulses from sensory receptors in the body to the CNS Motor (efferent) division Motor fibers - Transmits impulses from the CNS to effector organs

Restful state is what division of the autonomic NS

Parasympathetic

The ganglia that lie just beneath the parietal pleura in the thorax & beneath the parietal peritoneum in the abdomen are called

Paravertebral ganglia

Brain, Spinal Cord

Parts of the CNS

Nerves outside the brain and spinal cord

Parts of the PNS

An example of a reflex behavior is the..simple monosynaptic reflex

Patellar tendon reflex

Binds peripheral nerves into smaller bundles called fascicles

Perineurium

C3-5 pass into this nerve which conducts motor impulses to the muscle fibers of the diaphragm

Phrenic nerves

Thin layer that contains many nerves as well as blood vessels that nourish the underlying cells of the brain & spinal cord

Pia mater

Define PREsynaptic neuron

Presynaptic neuron: conducts impulses toward the synapse

Absolute Refractory period

Prevents the neuron from generating a nerve impulse Ensures that each action potential is separate Enforces one-way transmission of nerve impulses

Supply's muscles of the arms on the posterior sides & the skin of the forearms & hands

Radial nerves

Describe the structure and function of Ependymal Cells

Range in shape from squamous to columnar; may be ciliated Line the central cavities of the brain and spinal column Separate the CNS interstitial fluid from the cerebrospinal fluid in the cavities (barrier)

Near the center of the midbrain this mass of gray matter plays a role in maintains posture

Red nucleus

What are the effects of beta blockers?

Reduce sympathetic stimulation and reduce heart rate and blood pressure.

Electrical Current and the Body

Reflects the flow of ions rather than electrons There is a potential across the plasma membrane of all cells called the resting membrane potential. This potential is created and maintained by the Na/K pumps.

The simplest form of a nerve pathway that occurs at the level of the spinal cord, has some sensory receptors is called a

Reflex arc

k+

Repolarization is caused by ___ flowing out of the cell.

Sensations, perceptions, memory, reasoning, motor commands, coordination of muscular activity & regulation of visceral activities are all what

Responsibilities of the brain

Parasympathetic

Resting functions, digestion and urinating

Filters incoming sensory information, activates the cerebral cortex to wakefulness & is connected to centers of the cerebrum, basal ganglia, hypothalamus & the cerebellum

Reticular formation

Scattered throughout the brainstem is a complex network of nerve fibers associated with tiny islands of gray matter known as the

Reticular formation

block reuptake

SSRI's such as prozac will ____ _____ of neurotransmitters at the cleft.

graded potentials

STEP FIVE OF THE SYNAPSE OF THE NERVOUS SYSTEM: Binding of neurotransmitter opens ion channels, resulting in ____ ______.

cleft, postsynaptic

STEP FOUR OF THE SYNAPSE OF THE NERVOUS SYSTEM: Neurotransmitter diffuses across the synaptic ____ and binds to specific receptors on the ________ membrane.

positive, action potential

STEP FOUR OF THE SYNAPSE: ACH binding causes the ligand gated sodium ion channels to open and sodium diffuses into the cell, making the membrane more _______. If the memmbrane reaches threshold, a ___ ____ will be produced.

axon terminal

STEP ONE OF THE SYNAPSE OF THE NERVOUS SYSTEM: Action potential arrives at _____ ______.

presynaptic terminal

STEP ONE OF THE SYNAPSE: Action potentials arriving at the ____ ____ cause voltage gated calcium ion channels to open.

reuptake, enzymatic, diffusion

STEP SIX OF THE SYNAPSE OF THE NERVOUS SYSTEM: Neurotransmitter effects are terminated by _____ through transport proteins, ______ degradation, or ____ away from the synapse.

calcium, exocytosis

STEP THREE OF THE SYNAPSE OF THE NERVOUS SYSTEM: _____ entry causes neurotransmitter-containing synaptic vesicles to release their contents by _______.

cleft, ligand, sodium

STEP THREE OF THE SYNAPSE; ACH molecules diffuse from the presynaptic terminal across the synaptic ___ and bind to their receptors in the ___ gated ____ ion channels.

voltage

STEP TWO OF THE SYNAPSE OF THE NERVOUS SYSTEM: _______-gated calcium channels open and calcium enters the axon terminal.

vesicles

STEP TWO OF THE SYNAPSE: Calcium ions diffuse into the cell and cause synaptic _____ to release ACH.

Oligodendrocytes

Schwann Cells, and Satellite Cells Oligodendrocytes - branched cells that wrap CNS nerve fibers and produce myelin sheaths

PNS neuroglia help to form myelin sheaths around larger nerve fibers in the PNS?

Schwann cells

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS?

Schwann cells

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? Schwann cells astrocytes satellite cells oligodendrocytes

Schwann cells

what is vital to regeneration of damaged peripheral nerve fibres

Schwann cells

What two types of cells make up myelin sheaths?

Schwann cells (neurolemmocytes) in the PNS Oligodendrocytes in the CNS

Which of the following is described correctly?

Schwann cells provide the myelination in the peripheral nervous system.

The neurilemma of axons in the peripheral nervous system is formed by satellite cells. astrocytes. microglia. oligodendrocytes. Schwann cells.

Schwann cells.

Largest & longest nerves in the body

Sciatic nerves

Describe the structure and function of Myelin Sheaths

Segmented protein-lipoid sheath around most long or large-diameter axons In the PNS, Schwann cells wrap many times around the axon (look like little sausage links) It functions to: - Protect and electrically insulate the axon - Increase speed of nerve impulse transmission

Afferent=

Sensory

Ascending tracts that conduct afferent information to the brain are also called

Sensory

PNS components

Sensory receptors, nerves, ganglion, plexus

What type of functions does the brain stem perform?

Sensory, motor, and reflex functions.

Functional classification of neurons

Sensory: action potentials toward CNS Motor: action potentials away from CNS Interneurons: within CNS from one neuron to another

tentorium cerebelli

Separates Cerebellum and Brainstem from the occipital lobes of Cerebrum

ssri

Seratonin selective receptor inhibitor AKA

Patterns of Neural Processing

Serial Processing Input travels along one pathway to a specific destination Works in an all-or-none manner Example: spinal reflexes Parallel Processing Input travels along several pathways Pathways are integrated in different CNS systems One stimulus promotes numerous responses Example: smell may remind one of associated experiences

Describe the structure and function of Dendrites

Short, tapering, and diffusely branched Receptive region of a neuron [afferent] - receive sensory input Convey electrical signals toward the cell body as graded potentials

Graded potentials

Short-lived, local changes in membrane potential Decrease in intensity with distance Magnitude varies directly with the strength of the stimulus Alone or summed they can result in the initiation of nerve impulses on axons Only travel over short distances Occur only on dendrites Involved in the process of integration

That part of the nervous system that is voluntary and conducts impulses from the CNS to the skeletal muscles is the ________ nervous system.

So-ma-tic

Which of the following is true about the movement of ions across excitable living membranes? Ions always move passively across membranes. Ions always move actively across membranes through leakage channels. Sodium gates in the membrane can open in response to electrical potential changes. Ions always move from an area of higher concentration to an area of lower concentration

Sodium gates in the membrane can open in response to electrical potential changes.

The sodium-potassium exchange pump transports potassium and sodium ions in which direction(s)?

Sodium ions are transported out of the cell. Potassium ions are transported into the cell.

The 2 divisions of the PNS are the

Somatic & autonomic NS

Conscious activity is what division of the PNS

Somatic NS

Motor or efferent division

Somatic nervous system Conscious control of skeletal muscles Autonomic nervous system (ANS) Regulates smooth muscle, cardiac muscle, and glands 2 Divisions - sympathetic and parasympathetic

Why does the threshold increase when the internal between the stimuli decreases?

Some sodium channels have been inactivated and cannot be reopened immediately

What happens just after an axon is depolarized to threshold? Some potassium channels open. All potassium channels open. All sodium channels open. Some sodium channels open.

Some sodium channels open.

Slender column of nervous tissue that is continuous with the brain and extends down through the vertebral canal

Spinal cord

excitatory postsynaptic potential

Stimulatory effect on downstream cell AKA

Cerebrospinal fluid (CSF) is located in the

Subarachnoid space

Shallow grooves are called

Sulcus

Dense mass within the diencephalon that bulges into the 3rd ventricle on each side..acts a a central relay to & from the cerebral cortex

Thalamus

varies, on or off

The AMPLITUDE of a graded potential ____ while it is either ______ for an action potential.

permeability

The Action Potential is caused by ____ changes in the plasma membrane.

varies, same

The DURATION of a graded potential ___, while it will remain the ____ for an action potential.

trigger zone, axon

The LOCATION of the action potential is made for long distances; meaning that usually a gate will be at the ____ ____ and travel down the ____.

cell body, dendrite

The LOCATION of the graded potential is very localized for small distances; meaning that it usually consistes of the ___ ___ using a gate to the ____.

Which of the following best describes the Na+ and K+ concentrations across a neuron's plasma membrane?

The Na+ concentration is higher outside the cell compared to inside. The K+ concentration is higher inside the cell compared to outside.

arginine

The Nitric Oxide group of neurotransmitters contain what specific neurotransmitter discussed?

Imagine that the cell membrane from the previous problem becomes more permeable to . Predict how this will affect the RMP.

The RMP will be more positive.

postsynaptic

The ____ neuron is located at a synapse between neurons; the neuron recieving the signal.

presynaptic

The _____ neuron is located at a synapse between neurons; the neuron sending the signal.

electrical

The _____ synapse has a role in embrionic development of the nervous system.

sodium potassium pump, ATP

The _______ restores the original configuration, which requires ____

Tetraethylammonium (TEA) blocks voltage-gated K+ channels such that K+ cannot pass even when the channels are open. However, TEA leaves K+ leakage channels largely unaffected. How would you expect the action potential to change if you treated a neuron with TEA? The action potential would fail. Once the voltage reached threshold, it would return to the resting membrane potential. The membrane would depolarize and repolarize as usual, but no hyperpolarization beyond (more negative to) the resting membrane potential would occur. The action potential would depolarize as usual, but the repolarization phase would take longer, causing the action potential to be more broad in time. The membrane would depolarize as usual but then stay at that depolarized voltage (about +30 mV).

The action potential would depolarize as usual, but the repolarization phase would take longer, causing the action potential to be more broad in time.

etraethylammonium (TEA) blocks voltage-gated K+ channels such that K+ cannot pass even when the channels are open. However, TEA leaves K+ leakage channels largely unaffected. How would you expect the action potential to change if you treated a neuron with TEA?

The action potential would depolarize as usual, but the repolarization phase would take longer, causing the action potential to be more broad in time.

Multiple Sclerosis Treatment

The advent of disease-modifying drugs including interferon beta-1a and -1b, Avonex, Betaseran, and Copazone: Hold symptoms at bay Reduce complications Reduce disability

Why does the action potential only move away from the cell body?

The areas that have had the action potential are refractory to a new action potential.

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons? Action potentials would lack a repolarization phase. None, because the chemically-gated sodium channels would still function. Neurons would depolarize more rapidly. The absolute refractory period would be shorter than normal. The axon would be unable to generate action potentials

The axon would be unable to generate action potentials

arbor vitae

The branching tree looking structure of white matter found in the cerebellum.

Describe chemical concentrations of K+ and Na+ inside and outside a neuron.

The cell membrane is much more permeable/leaky to K+ ions Na+ / K+ pumps help to maintain resting gradients

Which of the following is true of the cerebral hemispheres of the human brain? Nearly the entire surface of the cerebral hemispheres is marked by elevated ridges called sulci. Nearly the entire surface of the cerebral hemispheres is marked by shallow grooves called gyri. The cerebral hemispheres account for about 83% of total brain mass. The longitudinal fissure separates the cerebral hemispheres from the cerebellum.

The cerebral hemispheres account for about 83% of total brain mass.

decussation

The crossing over of nerve fibers of a pathway from one side of the CNS to the other.

Neurons

The functional cell of the nervous system Composed of a soma (body), axon, and dendrites (fibers) Long-lived, amitotic, and have a high metabolic rate Plasma membranes function in electrical signaling

The gray horns of the spinal cord contain __________. neuroglia neuron cell bodies (somas) unmyelinated axons The gray horns contain all of these elements.

The gray horns contain all of these elements.

enkephalins, endorphins, angiotensin 2

The group Neuropeptides contain what three neurotransmitters?

Why does regeneration of the action potential occur in one direction, rather than in two directions?

The inactivation gates of voltage-gated Na+ channels close in the node, or segment, that has just fired an action potential.

negative, action potential

The inhibitory effect will cause the postsynaptic cell to become more _____ on the inside, and will therefore be further from threshold and less likely to fire a _____ _____.

If the potassium permeability of a resting neuron increases above the resting permeability, what effect will this have on the transmembrane potential? The inside of the membrane will become more negative. There will be almost no effect on transmembrane potential. The membrane will become depolarized. The membrane will depolarize to threshold. The inside of the membrane will become more positive.

The inside of the membrane will become more negative.

On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?

The inside surface of the plasma membrane is much more negatively charged than the outside surface.

Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?

The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.

The Nervous System

The master controlling and communicating system of the body Functions Sensory input -information gathered from sensory receptors monitoring stimuli Integration - interpretation of sensory input by the central nervous system (brain and spinal cord) Motor output - activates effector organs

What describes depolarization?

The membrane becomes less polarized

At rest, why is the transmembrane potential of a neuron (-70 mV) closer to the potassium equilibrium potential (-90 mV) than it is to the sodium equilibrium potential (+66 mV)?

The membrane is much more permeable to potassium ions than to sodium ions.

What characterizes depolarization, the first phase of the action potential?

The membrane potential changes from a negative value to a positive value.

What event triggers the generation of an action potential?

The membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV.

polarized fewer

The plasma membrane at rest is ______, meaning there are _____ positive ions inside the cell than outside the cell

Why is the parasympathetic nervous system referred to as the craniosacral division of the autonomic nervous system?

The preganglionic neurons of the parasympathetic nervous system either originate in the brainstem or the sacral spinal cord.

The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors.

The presence of concentration gradients and leak channels

During action potential propagation in an unmyelinated axon, why doesn't the action potential suddenly "double back" and start propagating in the opposite direction?

The previous axonal segment is in the refractory period.

In an unmyelinated axon, why doesn't the action potential suddenly "double back" and start propagating in the opposite direction?

The previous axonal segment is refractory.

neurotransmission

The process by which a nerve impulse is transmitted from a neuron to another cell.

Which of the following statements about the action potential is false? During the depolarization phase, membrane potential becomes positive. Repolarization occurs as potassium ions leave the axon. In the after-hyperpolarization phase, membrane potential approaches the potassium equilibrium potential. During the repolarization phase, sodium channels close and potassium channels open. The rapid depolarization phase is caused by the entry of potassium ions.

The rapid depolarization phase is caused by the entry of potassium ions.

Which of the following statements about receptor potentials is FALSE? The receptor proteins respond to stimuli. The receptor potential is carried by neuroglia. They can trigger an action potential. Odor molecules can act as stimuli.

The receptor potential is carried by neuroglia.

Which of the following statements about receptor potentials is FALSE?

The receptor potential is carries by neuroglia

How does blocking retrograde axoplasmic transport in an axon affect the activity of a neuron? The soma becomes unable to export products to the synaptic terminals. The neuron becomes unable to produce neurotransmitters. The neuron becomes unable to produce action potentials. The soma becomes unable to respond to changes in the distal end of the axon. The neuron becomes unable to depolarize when stimulated.

The soma becomes unable to respond to changes in the distal end of the axon.

What is the primary difference between the somatic nervous system and the autonomic nervous system?

The somatic nervous system allows us to consciously control our skeletal muscles, and the autonomic nervous system controls activity that humans cannot consciously control, such as the pumping of the heart and the movement of food through the digestive tract.

The myelin on myelinated neurons can be degraded or destroyed in diseases such as multiple sclerosis-a process called demyelination. If a myelinated neuron was affected by demyelination, how would this affect action potentials in that neuron?

The speed of action potential propagation would be slower.

Select the correct statement regarding synapses.

The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.

Select the correct statement regarding synapses. The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another. Cells with gap junctions use chemical synapases. Neurotransmitter receptors are located on the axons terminals of cells. The release of neurotransmitter molecules gives cells the property of being electrically coupled.

The synaptic cleft prevents an impulse from being transmitted directly from one neuron to another.

fast, slow

The synaptic delay states that all though an action potential propagates _____ the neurotransmission at the synapse is ______.

synaptic delay

The time required for neurotransmitters to be released from presynaptic cell, diffusion across the cleft, and binding of neurotransmitters to postsynaptic cell receptors.

Which brain waves are not normal for awake adults but are common for children? Alpha Delta Theta Beta

Theta

Which of the following is not characteristic of neurons? They have an exceptionally high metabolic rate. They conduct impulses. They have extreme longevity. They are mitotic.

They are mitotic.

Which of the following is NOT true of an electrical synapse?

They are specialized for release and reception of chemical neurotransmitters.

Which of the following is NOT true of an electrical synapse? Communication through these synapses may be unidirectional or bidirectional. They are less common than chemical synapses. They are specialized for release and reception of chemical neurotransmitters. Transmission across these synapses is very rapid.

They are specialized for release and reception of chemical neurotransmitters.

cerebellar peduncles **** not on test #15

Three thick nerve fiber tracts that link the cerebellum with the brainstem. *** not on test #15

schizophrenia

Too much dopamine causes what multiple personality disorder?

The funiculi of the white matter contain bundles of myelinated nerve fibers that compose major nerve pathways called

Tracts

descending tract

Tracts in the white matter of spinal cord that carry impulses away from the brain to effectors of the body

Which statement best characterizes a K+ leak channel? Common trans-membrane channels are always open for any ion to move through in the presence of K+. Chemically gated K+ channels that open and close according to the binding of other molecules. Trans-membrane protein channels that are always open to allow K+ to cross the membrane without the additional input of energy. Trans-membrane channels that use energy to allow the movement of K+ across the membrane.

Trans-membrane protein channels that are always open to allow K+ to cross the membrane without the additional input of energy

Which statement best characterizes a leak channel?

Trans-membrane protein channels that are always open to allow to cross the membrane without the additional input of energy.

saltatory conduction

Transmission of an action potential along a myelinated fiber in which the nerve impulse appears to leap from node (of ranvier) to node.

Cranial nerves V..largest..3 branches: opthalmic, maxillary, mandibular..mixed

Trigeminal

Cranial nerves IV..primarily motor

Trochlear

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons.

True

A postsynaptic potential is a graded potential that is the result of a neurotransmitter released into the synapse between two neurons. T or F

True

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane.

True

A stimulus traveling toward a synapse appears to open calcium ion channels at the presynaptic end, which in turn promotes fusion of synaptic vesicles to the axonal membrane. T or F

True

Acetylcholine is the substance released by the axonal endings of the somatic efferent fibers and by the parasympathetic nerve fiber endings T/F

True

An action potential is a phenomenon that either happens completely or doesn't happen at all.

True

Autonomic reflex centers occur in the spinal cord, medulla, and midbrain T/F

True

Axon diameter and degree of myelination determine nerve impulse conduction velocity.

True

Axon diameter and degree of myelination determine nerve impulse conduction velocity. T or F

True

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system T/F

True

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system.

True

Cell bodies of sensory neurons may be located in ganglia lying outside the central nervous system. T or F

True

Dendrites and axons are both armlike processes that extend from cell bodies.

True

During depolarization, the inside of the neuron's membrane becomes less negative.

True

During depolarization, the inside of the neuron's membrane becomes less negative. T or F

True

Efferent nerve fibers may be described as motor nerve fibers T/F

True

Efferent nerve fibers may be described as motor nerve fibers.

True

Efferent nerve fibers may be described as motor nerve fibers. T or F

True

Enkephalins and endorphins are peptides that act like morphine.

True

Enkephalins and endorphins are peptides that act like morphine. T or F

True

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them.

True

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them. T or F

True

If bacteria invaded the CNS tissue, microglia would migrate to the areal to engulf and destroy them T/F

True

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.

True

Supply's muscles of the forearms & hands & the skin of the hands

Ulnar nerves

membrane potentials

Used to integrate, send, and receive information Types of signals - graded potentials and action potentials Changes are caused by three events Depolarization - the inside of the membrane becomes less negative Repolarization - the membrane returns to its resting membrane potential Hyperpolarization - the inside of the membrane becomes more negative than the resting potential

Cranial nerves X..longest nerve..some taste..heart & smooth muscles & glands of thorax/abdomen..mixed

Vagus

What nerve carries roughly 75% of all fibers in the parasympathetic division

Vagus

The 4 interconnected cavities that lie in the cerebral hemisphere and the brain stem are know as what

Ventricles

Structure that connects the cerebellar hemispheres at the midline is called the

Vermis

Cranial nerves VIII..balance & hearing..sensory

Vestibulocochlear

both of the above

What accounts for the gray color of gray matter? A) presence of Nissl bodies B) absence of myelin C) both of the above D) neither of the above

resting potential, depolarization, peak depolarization, repolarization, hyperpolarization

What are the five basic steps of generating an action potential?

neuron, muscle, gland

What are the three postsynaptic membrane receptors for a chemical synapse?

neuromuscular junction

What example of a neuron to effector chemical synapse did we discuss that plays a role in muscle excitation?

in parallel after discharge circuits, a single input leads to multiple individual outputs

Which statement is false regarding neural circuits? A) converging circuits provide multiple input to a single postsynaptic neuron B) diverging circuits spread information from one neuron or pool to several others C) in parallel-after-discharge circuits, a single input leads to multiple individual outputs D) in reverberating circuits, feedback repeatedly stimulates the circuit in a cyclic pattern

Multiple sclerosis (MS) is a disease that stops action potential propagation by destroying the myelin around (normally) myelinated axons. Which of the following best describes how MS stops action potential propagation?

Without myelin, the internode membrane resistance decreases, preventing local currents from reaching adjacent nodes.

Potassium, Sodium

_____ rushes out of the neuron after _____ rushes in, which repolarizes the membrane

fourth ventricle

a CSF filled cavity in the brainstem just anterior to the cerebellum ( 5 )

What is a seizure disorder?

a disorder characterized by abnormal, uncooordinated tetanic contracttions of varying groups of muscles. The result of sudden bursts of abnormal neuron activity.

Describe the shape of the thalamus:

a dumbbell-shaped mass of gray matter made up of many nuclei.

interventricular foramen

a foramen between the lateral ventricles & the third ventricle where CSF passes ( 2 )

What is dementia?

a general syndrome that includes loss of: memory, attention span, intellectual capacity, personality, and motor control.

Define the term Electroencephalogram:

a graphic record of the brain's action potentials used to evaluate nerve tissue function.

When the stimulus voltage is increased,

a greater-than-threshold depolarization results and sodium permeability into the cell increases to overcome the potassium exiting

glossopharyngeal nerve ( IX )

a mixed nerve; sensory: from pharynx, & TONGUE; motor: to salivary glands, & MUSCLES OF THE PHARYNX for SWALLOWING ( L )

trigeminal nerve ( V )

a mixed nerve; sensory: ophthalmic division for sensory from surface of & around the eye; maxillary division: sensory from upper teeth. motor: the muscles of mastication, throat, & in the floor of mouth ( H )

vagus nerve ( X )

a mixed nerve; sensory: pharynx, esophagus, & viscera. somatic motor: speech & swallowing. autonomic motor: viscera & heartbeat ( M )

oculomotor nerve ( III )

a motor nerve: it carries impulses to muscles that raise eyelids, move the eyes, focus lens, controls the iris ( F )

abducens nerve ( VI )

a motor nerve: it carries impulses to the rectus muscles that move the eye ( I )

What type of stimulus is required for an action potential to be generated? a) a threshold level depolarization b) a suprathreshold stimulus c) hyperpolarization d) multiple stimuli

a) a threshold level depolarization

What is the Pituitary gland?

a neuroendocrine gland formed from the hypothalamus.

A postsynaptic cell can be a neuron, a muscle cell, or a secretory cell. What is an example of a presynaptic cell?

a neuron

A postsynaptic cell can be a neuron, a muscle cell, or a secretory cell. What is an example of a presynaptic cell? a muscle cell a neuron a secretory cell a Schwann cell

a neuron

In which of the following would the delay between stimulus and response be greater? a monosynaptic reflex a polysynaptic reflex

a polysynaptic reflex

The membrane potential that occurs when neurotransmitters bind to their receptors is called

a postsynaptic potential

Multiple sclerosis

a progressive, autoimmune disease in which a protein component of the myelin sheath is attacked and the sheath is destroyed Symptoms- depend on location of nerve damage: vision, sensation, coordination, movement, speech, bladder control, and bowel control Women ages 20-40 Therapies but no cure

Which of the following describes a change from the resting membrane potential? a receptor potential an action potential a receptor potential, a synaptic potential or an action potential a synaptic potential

a receptor potential, a synaptic potential or an action potentia

Which of the following describes a change from the resting membrane potential?

a receptor potential, a synaptic potential, or an action potential

When the interval between the stimuli decreases,

a second action potential is generated until the interval reaches the absolute refractory period

vestibulocochlear nerve ( VIII )

a sensory nerve; sensory from hearing receptors, & equilibrium receptors of the ear ( K )

A weak, subthreshold stimulus will result in _______.

a small depolarization at the receiving end of the neuron

The velocity of the action potential is fastest in which of the following axons?

a small myelinated axon

What is the dorsal root ganglion?

a small region of grey matter, shaped like a bump, that is comprised of the cell bodies of the unipolar nerves in the dorsal nerve root.

What is formed by thee joining of the dorsal and ventral nerve roots?

a spinal nerve

Define consciousness:

a state of awareness of one's self, one's environment, and other beings.

Depolarization

a stimulus depolarizes the neuron's membrane

If the axolemma becomes more permeable to potassium ion: the inside of the membrane will have a positive charge the membrane will depolarize to threshold a stronger stimulus will be required to cause an action potential the membrane will depolarize to +30 mV sodium ions will enter the cell to replace the lost potassium ions

a stronger stimulus will be required to cause an action potential

arachnoid mater

a thin web-like membrane located between dura mater & pia mater ( 14 )

What type of stimulus is required for an action potential to be generated?

a threshold level stimulas

pineal gland

a tiny structure at the base of the brain that produces melatonin ( k )

What is a membrane potential?

a voltage or electrical charge across the plasma membrane

Which of the following is the conducting region of the neuron? a) Axon b) Dendrites c) Ganglia d) Neurofibrils

a) Axon

Which of the following is true of axons? a) Each neuron has a single axon. b) Each dendrite may have occasional branches along its length, which are called axons. c) Each axon may have occasional branches along its length, which are called dendrites. d) Each neuron has hundreds of axons.

a) Each neuron has a single axon.

Which of the following PNS neuroglia help to form myelin sheaths around larger nerve fibers in the PNS? a) Schwann cells b) Oligodendrocytes c) Astrocytes d) Satellite cells

a) Schwann cells

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? a) Schwann cells b) oligodendrocytes c) satellite cells d)astrocytes

a) Schwann cells

Which of the following allows us to consciously control our skeletal muscles? a) The somatic nervous system b) The sympathetic division of the autonomic nervous system c) The parasympathetic division of the autonomic nervous system d) The involuntary nervous system

a) The somatic nervous system

Which of the following neurotransmitters is released at the neuromuscular junction by motor neurons?

acetylcholine

Which of the choices below describes the ANS? a) motor fibers that conduct nerve impulses from the CNS to smooth muscle and glands b) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors form the special senses of vision, hearing, taste, and smell to the CNS c) sensory and motor neurons that supply the digestive tract d) motor fibers that conduct nerve impulses from he CNS to skeletal muscles

a) motor fibers that conduct nerve impulses from the CNS to smooth muscle and glands

The substance released at axon terminals to propagate a nervous impulse is called a(n) ________. a) neurotransmitter b) cholinesterase c) ion d) biogenic amine

a) neurotransmitter

Which of the following are gaps found along a myelin sheath? a) nodes of Ranvier b) axolemma c) terminal boutons d) outer collare of perinuclear cytoplasm

a) nodes of Ranvier

Which of the following is NOT a type of circuit? a) per-discharge circuits b) converging circuits c) reverberating circuits d) diverging circuits

a) per-discharge circuits

An impulse from one nerve cell is communicated to another nerve cell via the ________. a) synapse b) effector c) receptor d) cell body

a) synapse

Saltatory conduction is made possible by _______. a) the myelin sheath b) erratic transmission of nerve impulses c) diphasic impulses d) large nerve fibers

a) the myelin sheath

Irritability

ability to respond to stimuli

Conductivity

ability to transmit an impulse

why are myelin sheaths exceptionally good electrical insulators

absence of channel and carrier proteins

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________.

absolute refractory period

Astrocytes

abundant, star shapes cells that brace the neurons they form barrier between capillaries and neurons AND control chemical environment of the brain

how are neurons classified

according to number of processes extending from their cell body- multipolar, bipolar, unipolar

Cholinergic synapses release the neurotransmitter acetylcholine. adrenalin. serotonin. GABA. norepinephrine.

acetylcholine

In myasthenia gravis, antibodies attack __________ receptors at the neuromuscular junction of skeletal muscles.

acetylcholine

The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken down by an enzyme before being returned?

acetylcholine

The neurotransmitter used between preganglionic and postganglionic cells in the autonomic nervous system is __________.

acetylcholine

What is the neurotransmitter in the somatic nervous system?

acetylcholine

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?

acetylcholine

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? cholinesterase gamma aminobutyric acid acetylcholine norepinephrine

acetylcholine

motor

action potentials from CNS to receptors

sensory

action potentials from receptors to CNS

The obturator nerve is distributed to the skin over buttocks. skin over the perineum. extensors of the hip. adductors of the hip. biceps femoris.

adductors of the hip.

The part of the peripheral nervous system that carries sensory information to the CNS is designated autonomic. efferent. afferent. somatic. motor.

afferent

The all-or-none principle states that all stimuli great enough to bring the membrane to threshold will produce identical action potentials. all stimuli will produce identical action potentials. only motor stimuli can activate action potentials. only sensory stimuli can activate action potentials. the greater the magnitude of the stimuli, the greater the magnitude of the action potential

all stimuli great enough to bring the membrane to threshold will produce identical action potentials.

For the receptor potential

amplitude can vary with the stimulus intensity, requires the appropriate stimulus and can be graded with a stimulus intensity

Which of the following correctly describes a graded potential?

amplitude of various sizes

A depolarizing synaptic potential is also known as _______.

an excitatory postsynaptic potential

plexus

an extensive network axons outside CNS

A stimulus that changes a postsynaptic neuron's membrane from resting potential to -85 mV is: a saltatory stimulus an excitatory stimulus an inhibitory stimulus a depolarizing stimulus a temporal stimulus

an inhibitory stimulus

Products from the soma of a neuron are transported to the synaptic terminals by ________ axoplasmic transport.

anterograde

what is movement toward the axon terminals called

anterograde movement

The subarachnoid space lies between what two layers of meninges? arachnoid and dura arachnoid and epidura arachnoid and pia dura and epidura

arachnoid and pia

All of the following are true of polysynaptic reflexes, except that they involve pools of interneurons. have reverberating circuits that prolong the reflexive motor response. are intersegmental in distribution. involve reciprocal innervation. are arranged according to dermatomes

are arranged according to dermatomes.

Nerve cell adhesion molecules (N-CAMs) ________.

are crucial for the development of neural connections

Nerve cell adhesion molecules (N-CAMs) ________. are crucial for the development of neural connections are crucial in the production of neurotransmitters release nerve growth factor are found on "pathfinder" neurons

are crucial for the development of neural connections

All of the following are true of muscle spindles, except that they consist of specialized fibers called intrafusal fibers. are innervated by gamma motor neurons. are the receptor for the stretch reflex. are found in tendons. are found within skeletal muscle.

are found in tendons.

IPSPs (inhibitory postsynaptic potentials) are local depolarizations. block the efflux of calcium ions. increase membrane permeability to sodium ions. are local hyperpolarizations. block the efflux of potassium ions.

are local hyperpolarizations.

Cl- inside cell

are repelled by proteins and exit through always open non gated channels

lumbar subarachnoid space

area of the subarachnoid space that contains the most CSF due to spinal cord growth

Neurons that have one axon and one dendrite, with the soma in between, are called bipolar. multipolar. anaxonic. unipolar. tripolar.

bipolar.

Which of the following functions does NOT increase during the fight-or-flight response?

blood flow to gastrointestinal organs

How could a CVA cause Hemiplegia?

by temporarily disabling or by killing all the motor neurons on one side of the brain, primarily the precentral gyrus. - this would cause all muscles on one side of the body to become paralyzed.

What type of stimulus is required for an action potential to be generated? a) multiple stimuli b) a single stimulus generated by the neuron that is to produce the action potential c) a threshold level stimulus d) a single stimulus followed immediately by a second stimulus

c) a threshold level stimulus

What is the effect of norepinephrine on the heart? a) a decrease in heart rate b) a decrease in stroke volume c) an increase in heart rate d) Norepinephrine does not affect the heart

c) an increase in heart rate

Which part of the neuron is responsible for generating a nerve impulse? a) dendrite b) Nissl substance c) axon d) soma

c) axon

Which of the following is responsible for the overall integration of the autonomic nervous system (ANS)? a) brain stem b) cerebral cortex c) hypothalamus d) spinal cord

c) hypothalamus

Schwann cells are functionally similar to ________. a) astrocytes b) microglia c) oligodendrocytes d) ependymal cells

c) oligodendrocytes

Which of the following types of glail cells produces myelin sheaths that insulate axons, or nerve fibers, in the central nervous system (CNS)? a) ependymal cells b) microglia c) oligodendrocytes d) astrocytes

c) oligodendrocytes

Immediately after an action potential has peaked, which cellular gates open? a) calcium b) chloride c) potassium d) sodium

c) potassium

For which of the following activities is the parasympathetic nervous system generally responsible? a) vigorous physical activity b) fight-or-flight responses c) resting and digesting d) sweating and dilating pupils

c) resting and digesting

Which of the following is NOT an autonomic nervous system (ANS) effector? a) glands b) cardiac muscle c) skeletal muscle d) smooth muscle

c) skeletal muscle

Which ion channel opens in response to a change in membrane potential and participates in the generation and conduction of action potentials? a) mechanically gated channel b) ligand-gated channel c) voltage-gated channel d) leakage channel

c) voltage-gated channel

Which ion triggers synaptic vesicles to discharge neurotransmitter into the synaptic cleft? potassium calcium magnesium sodium

calcium

Presynaptic facilitation by serotonin is caused by blockage of calcium channels in the presynaptic membrane. increased extracellular concentration of sodium ion. calcium channels in the presynaptic membrane remaining open longer. increased extracellular concentration of potassium ion. temporal summation.

calcium channels in the presynaptic membrane remaining open longer.

graded potentials

can summate and spread in decremental fashion

All of the following are true of neural reflexes, except that they involve at least two neurons. are automatic motor responses. are the simplest form of behavior. cannot be modified by the brain. help preserve homeostasis.

cannot be modified by the brain.

Nissl substance

chromatophilic substance = rough E.R: primary site of protein synthesis

If extracellular concentration of Ca2+ increases- gates ____ and membrane repolarizes or becomes _______.

close, hyperpolarized

what are nuclei

clusters of cell bodies in the CNS

what are ganglia

clusters of cell bodies in the PNS

Nuclei

clusters of cell bodies within the central nervous system

Branches that may occur along an axon are called hillocks. synapses. collaterals. telodendria. synaptic terminals.

collaterals.

nerve

collection of axons in PNS

ganglion

collection of neuron cell bodies outside PNS

Ganglia

collections of cell bodies outside the central nervous system

In the spinal cord, white matter is separated into ascending and descending tracts organized as ganglia. nuclei. columns. nerves. horns.

columns

how do astrocytes signal each other

creating slow paced intracellular calcium pulses, releasing extracellular messengers

The ________ reflex complements the flexor reflex by activating contralateral muscles. crossed extensor flexor tendon stretch reciprocal

crossed extensor

The __________ reflex involves activating muscles contralateral to the receptor. crossed extensor stretch tendon flexor

crossed extensor

post-central gyrus

cutaneous sensory area pressure, pain, temperature, and position and movement sensation are received and interpreted.

Which of the following does not describe the ANS? a) general visceral motor system b) a system of motor neurons that innervates smooth and cardiac muscle and glands c) involuntary nervous system d) a system of motor neurons that innervates all muscle cells

d) a system of motor neurons that innervates all muscle cells

The two divisions of the autonomic nervous system (ANS) normally have a(n)_______ relationship. a)disruptive b) synergistic c) mutualistic d) antagonistic

d) antagonistic

An inhibitory postsynaptic potential (IPSP) is associated with ________. a) lowering the threshold for an action potential to occur b) a change in sodium ion permeability c) opening of voltage-regulated channels d) hyperpolarization

d) hyperpolarization

Which of the following is not a function of the autonomic nervous system? a) innervation of cardiac muscle b) innervation of glands c) innervation of smooth muscle of the digestive tract d) innervation of skeletal muscle

d) innervation of skeletal muscle

Which of the choices below describes the ANS? a) sensory and motor neurons that supply the digestive tract b) sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS c) motor fibers that conduct nerve impulses from the CNS to skeletal muscles d) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

d) motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________. a) positively charged and contains more sodium b) positively charged and contains less sodium c) negatively charged and contains more sodium d) negatively charged and contains less sodium

d) negatively charged and contains less sodium

Which of the following circuit types is involved in the control of rhythmic activities such as the sleep-wake cycle, breathing , and certain motor activities (such as arm swinging when walking)? a) converging circuits b) diverging circuits c) parallel after-discharge circuits d) reverberating circuits

d) reverberating circuits

Increasing the amount of myelination

decreases the time between action potentials

ncreasing the amount of myelination _______.

decreases the time between action potentials

Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon?

degree of myelination of the axon

what do astrocytes look like

delicate branching sea anemones 'star cells' s

where is the main receptive or input region

dendrite

Which of the following are the main receptive or input regions found in neurons?

dendrites

what are the two types of neuron processes and how do they differ

dendrites, axons. differ in structure and function of plasma membranes

white matter

dense collections of myelinated fibers

how are cells in the CNS packed

densely packed, tightly intertwined

Calcium and magnesium are both

divalent cations

Calcium and magnesium are both _______.

divalent cations

Which of the following circuit types is exemplified by impulses that travel from a single neuron of the brain, activate one hundred or more motor neurons in the spinal cord, and excite thousands of skeletal muscle fibers?

diverging circuits

The __________ gray horns contain sensory nuclei. intermediate ventral dorsal lateral

dorsal

The ________ of each spinal nerve innervates the skin and muscles of the back. gray ramus communicantes ventral ramus dermatome dorsal ramus white ramus communicantes

dorsal ramus

The tough, fibrous, outermost covering of the spinal cord is the periosteum. arachnoid. epidural block. pia mater. dura mater.

dura mater.

The connective tissue layer that covers Schwann cells is the __________. endomysium endoneurium epineurium perineurium

endoneurium

The layer of connective tissue that surrounds individual axons within a peripheral nerve is termed the subneurium. metaneurium. endoneurium. aponeurium. perineurium.

endoneurium

Which of the following neurotransmitters inhibits pain and is mimicked by morphine, heroin, and methadone?

endorphin

Which neurotransmitter(s) is/are the body's natural pain killer?

endorphins

To reach threshold, the amount of sodium _______.

entering the cell must overcome the potassium exiting

Caveolae are closely associated with all of the following except ________.

enzymes involved in cell metabolism

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called?

ependymal cells

What are ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid called? Schwann cells astrocytes oligodendrocytes ependymal cells

ependymal cells

What cells line the ventricles of the brain? astrocytes epithelial cells neurons ependymal cells

ependymal cells

Which of the following types of glial cells line the central cavities of the brain and spinal cord, where they help to circulate the cerebrospinal fluid?

ependymal cells

what is the role of astrocytes

exchange between capillaries and neurons, determine capillary permeability, guiding migration of young neurons, synapse formation, control chemical environment around neuron, mop up leaked K ions and recapture released neurotransmitters

Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron?

excitatory postsynaptic potential

Which membrane potential occurs because of the influx of Na+ through chemically gated channels in the receptive region of a neuron? inhibitory postsynaptic potential inhibitory action potential excitatory postsynaptic potential action potential

excitatory postsynaptic potential

what do the neurotransmitters do

excite or inhibit neurons (or effector cells) witch which the axon is in close contact

Which of the following best describes the cerebrum? visceral command center decussation center executive suite motor command center

executive suite

A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____.

exocytosis

Neurotransmitter is released from presynaptic neurons through what mechanism?

exocytosis

Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________.

extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber

axon

extends from cell body to terminal endings

EPSPs (excitatory postsynaptic potentials) occur when more potassium ions than usual leak out of a cell. chloride ions enter a cell. extra sodium ions enter a cell. more calcium ions than usual leak out of a cell. hyperpolarizations occur.

extra sodium ions enter a cell.

crossed-extensor reflex **** not on test #3`

flexor muscles contract in response to stimulus, contralateral flexor muscles are inhibited, & contralateral extensor muscles contract to maintain balance *** not on test #3

Define Cerebrospinal Fluid:

fluid found in the cavities and canals of the brain and spinal cord.

Define Ventricles: How many are there?

fluid-filled spaces (4) within the brain.

Damage to ependymal cells would most likely affect the formation of cerebrospinal fluid. formation of ganglia. transport of neurotransmitters within axons. formation of myelin sheaths. repair of axons.

formation of cerebrospinal fluid.

In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by regenerating cell bodies for the neurons. clearing away cellular debris. producing more satellite cells that fuse to form new axons. forming a cellular cord that directs axonal regrowth. producing new axons.

forming a cellular cord that directs axonal regrowth.

where is the golgi apparatus in a neuron

forms arc or complete circle around nucleus

Schwann cells

forms the myelin sheath in the peripheral nervous system

globus pallidus

found deep within cerebrum, inhibit neurotransmitter dopamine

Bipolar neurons are commonly ________.

found in the retina of the eye

Bipolar neurons are commonly ________. motor neurons called neuroglial cells found in the retina of the eye found in ganglia

found in the retina of the eye

auditory area

found in the temporal lobes, contain the centers for hearing

Which of the following is the most important excitatory neurotransmitter in the brain that is important in learning and memory? glycine gamma aminobutyric acid glutamate noradrenaline serotonin

glutamate

________ potentials are short-lived, local changes in membrane potential that can be either depolarized or hyperpolarized

graded

spatial summation

graded potentials at two different dendrites

A typical spinal nerve has a __________ ramus consisting of unmyelinated axons that innervate smooth muscles. dorsal ventral gray whitw

gray

Axons crossing from one side of the spinal cord to the other within the gray matter are found in the gray commissures. lateral gray horns. posterior gray horns. anterior gray horns. white commissures.

gray commissures.

The postganglionic fibers that connect an autonomic ganglion in the thoracic or lumbar region with the spinal nerve and contain postganglionic fibers that innervate glands in the body wall or limbs are white rami communicantes. ventral ramus. gray rami communicantes. dorsal ramus. dermatomes.

gray rami communicantes

what is the functional classification of a neuron

groups neurons according to direction in which the nerve impulse travels relative to the CNS. sensory neurons, motor neurons, interneurons

Ridges of tissue on the surface of the cerebral hemispheres are called ________. ganglia fissures sulci gyri

gyri

long term memory *** not on test #9

it changes the structure or function of neurons in ways that enhance synaptic transmission by establishing certain patterns of synaptic connections *** not on test #9

why could the peripheral process of a unipolar neuron be classified as the axon

it generates and conducts an impulse, when large is heavily myelinated, has a uniform diameter and is indistinguishable microscopically from an axon

functions of the spinal cord

it transmits nerve impulses to and from the brain & is the center for reflexes

If a nerve cell receives many IPSPs at the same time, __________. the membrane potential will depolarize it will show temporal summation the nerve cell will approach threshold the nerve cell will be strongly excited

it will show temporal summation

If an increase in extracellular potassium hyper polarizes a neuron,

it would change the membrane potential to a more negative value

what does an axon depend on

its cell body to renew the necessary proteins and membrane components and on efficient transport mechanisms to distribute them. axons decay if cut or severely damaged

massa intermedia

joins the two lobes of the thalamus ( 12 )

Synapse

junction between nerves

in motor neurons the impulse is generated where

junction of the axon hillock and axon (trigger zone)

Where is the Pineal body located?

just above and behind the midbrain.

Where is the cerebellum located?

just below the posterior portion of the cerebrum.

what is structurally important about dendrites

large surface area for receiving signals from other neurons

Type A nerve fiber

large-diameter, myelinated. Conduct at 15-120 m/s. Motor neurons supplying skeletal and most sensory neurons

Neural tracts that convey life-saving information to the brain concerning burning pain would be ________. posterior spinothalamic anterior spinothalamic lateral spinothalamic reticulospinal

lateral spinothalamic

The frontal lobe is separated from the temporal lobe by the ________. lateral sulcus central sulcus cranial fossa longitudinal fissure

lateral sulcus

meninges

layers of CT that surround & protect the brain and spinal cord & form a complete enclosure & contain CSF

A viral disease that destroys the cells of the anterior gray horn will mainly interfere with crude touch and temperature sense. block autonomic regulation. affect visceral motor function. interfere with position sense. lead to skeletal muscle weakness or paralysis.

lead to skeletal muscle weakness or paralysis.

The channels that provide for the movement of potassium in the resting neuron are _______.

leakage

Which type of ion channel opens when a chemical binds to it?

leakage channels

Bill contracts a viral disease that destroys cells in the posterior gray horns in his spinal cord. As a result, which of the following would you expect? inability to breathe problems with moving his legs uncontrollable sweating of his feet loss of sensation in his torso problems with moving his arms

loss of sensation in his torso

what do lumbar nerves control and how many?

lower abdomen hips legs 5

The typical concentration of sodium is

lower than potassium intracellularly

The typical concentration of sodium is

lower than potassium intracellularly.

What is the major role of the Na+-K+ pump in maintaining the resting membrane potential?

maintaining the concentration gradients for Na+ and K+ across the cell membrane

Multipolar neurons

many extensions directly from the cell body includes all motor and inter-neurons

basal nuclei *** not on test #1

masses of grey matter called caudate nucleus, putamen, & globus pallidus deep within the cerebral hemispheres; they produce the neurotransmitter dopamine; controls certain muscular movements *** not on test #1

Graded potentials produce an effect that spreads actively across the membrane surface. are often all-or-none. may be either a depolarization or a hyperpolarization. cause repolarization. produce an effect that increases with distance from the point of stimulation.

may be either a depolarization or a hyperpolarization.

Which of the following describes a B fiber?

medium diameter, lightly myelinated

Which of the following is not involved in creating the resting potential of a neuron? membrane permeability for sodium ions greater than potassium ions membrane permeability for potassium ions greater than sodium ions diffusion of sodium ions into the cell diffusion of potassium ions out of the cell The interior of the plasma membrane has an excess of negative charges.

membrane permeability for sodium ions greater than potassium ions

Hyper polarization

membrane potential is more negative, move further from 0

Depolarization

membrane potential is more positive, closer to 0

septum pellucidum

membranous structure that separates the lateral ventricles of the cerebral hemispheres ( b )

Which of the following is not a function of the neuroglia? secretion of cerebrospinal fluid memory support phagocytosis maintenance of blood-brain barrier

memory

The blood-brain barrier is effective against ________. nutrients such as glucose metabolic waste such as urea alcohol anesthetics

metabolic waste such as urea

After a stroke, what type of glial cell accumulates within the affected brain region? oligodendrocytes ependymal cells Schwann cells satellite cells microglia

microglia

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?

microglia

Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons? ependymal cells oligodendrocytes microglia astrocytes

microglia

Small, wandering cells that engulf cell debris and pathogens in the CNS are called astrocytes. ependymal cells. satellite cells. microglia. oligodendrocytes.

microglia.

what is important in maintaining cell shape and integrity in a neuron

microtubules, neurofibrils

The middle primary brain vesicle, the mesencephalon, gives rise to which adult brain structure? cerebrum midbrain diencephalon medulla oblongata

midbrain

The brain stem consists of the ________. midbrain, medulla, and pons pons, medulla, cerebellum, and midbrain midbrain only cerebrum, pons, midbrain, and medulla

midbrain, medulla, and pons

If a person has a crush injury to the C3-C5 spinal segments, you would expect that he would have full range of motion in all extremities. would be in a coma. could walk without difficulty. might be unable to breathe on his own. would have difficulty chewing and moving the tongue.

might be unable to breathe on his own.

what do microglia do when they detect an injured neuron

migrate towards it and turn into macrophage that phagocytes' the the invading microorganisms or neuronal debris

what substances are moved in the retrograde direction

mostly organelles being returned to the cell body for degradation or recycling, also an important means of intracellular communication for advising the cell body of conditions at the axon terminals, for delivering to the cell body vesicles containing signal molecules

gray matter

mostly soma and short unmyelinated fibers

Which of the following types of neurons carry impulses away from the central nervous system (CNS)?

motor

Which of the following types of neurons carry impulses away from the central nervous system (CNS)? motor association sensory afferent

motor

Which of the choices below describes the ANS?

motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

Which of the choices below describes the ANS? motor fibers that conduct nerve impulses from the CNS to skeletal muscles sensory and motor neurons that supply the digestive tract sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

What is the function of the Vagus nerve?

motor impulses to heart & smooth muscles and glands in viscera.

What is the function of the Glosspharygeal nerve?

motor impulses to swallowing muscles & salivary glands.

Nerve cells (neurons) that control peripheral effectors are known as __________. motor neurons peripheral neurons axons afferent fibers

motor neurons

Which of the following best explains diffusion?

movement of molecules from an area of high concentration to an area of low concentration

Complete the following sentence. The operation of the ATPase pump __________.

moves 3 to the ECF and 2 to the cytoplasm

A distinction about the flexor reflex is that it __________. prevents a muscle from overstretching moves a limb away from a painful stimulus prevents a muscle from generating excessive tension is an example of a monosynaptic reflex

moves a limb away from a painful stimulus

The flexor reflex usually depends on cranial neurons. moves a limb away from a painful stimulus. is an example of a monosynaptic reflex. prevents a muscle from overstretching. prevents a muscle from generating damaging tension.

moves a limb away from a painful stimulus.

Which of the following diseases is directly related to demyelination?

multiple sclerosis

Most CNS neurons fall into which structural category? anaxonic unipolar bipolar multipolar

multipolar

Neural circuits occur in all of these patterns except __________. multipolar divergent convergent reverberating

multipolar

Which of the following is NOT a functional classification of neurons?

multipolar

Which of the following is NOT a functional classification of neurons? multipolar efferent sensory interneurons

multipolar

Neurons that have several dendrites and a single axon are called bipolar. unipolar. multipolar. anaxonic. tripolar.

multipolar.

Recognized neuronal circuit patterns include all of the following, except parallel processing. reverberating. convergent. divergent. multipolar.

multipolar.

The most abundant class of neuron in the central nervous system is pseudopolar. multipolar. bipolar. unipolar. anaxonic.

multipolar.

What does the somatic nervous system innervate?

muscle

Saltatory propagation occurs in _________ axons, in which action potentials _________. Select the best answer. myelinated; move from one node of Ranvier to another unmyelinated; move from one node of Ranvier to another unmyelinated; spread by depolarizing the adjacent region of the axon membrane myelinated; move continuously along the axon toward the axon hillock

myelinated; move from one node of Ranvier to another

what do cervical nerves control and how many?

neck shoulders arms hands 8

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________.

negatively charged and contains less sodium

In what way does the interior surface of a cell membrane of a resting (nonconducting) neuron differ from the external environment? The interior is ________. negatively charged and contains more sodium negatively charged and contains less sodium positively charged and contains more sodium positively charged and contains less sodium

negatively charged and contains less sodium

Each of the following is an example of a neuroeffector junction, except the junction between a neuron and a(n) smooth muscle cell. exocrine gland cell. skeletal muscle cell. nerve cell. endocrine gland cell.

nerve cell

Neurons

nerve cell specialized to transmit messages

The gray horns of the spinal cord contain mainly nerve cell bodies. funiculi. columns. nerve tracts. meninges.

nerve cell bodies.

what is any long axon called

nerve fibre

the 12 cranial nerves labeled

nerves labeled

what are exceptions to the amitotic rule

olfactory epithelium and hippocampal regions contain stem cells that can produce new neurons throughout life

In multiple sclerosis, the cells that are the target of an autoimmune attack are the _________. neurons muscle cells Schwann cells oligodendrocytes

oligodendrocytes

Schwann cells are functionally similar to ________.

oligodendrocytes

Schwann cells are functionally similar to ________. ependymal cells oligodendrocytes astrocytes microglia

oligodendrocytes

Which of the following types of glial cells produces the myelin sheaths that insulate axons, or nerve fibers, in the central nervous system (CNS)?

oligodendrocytes

Which of the following types of glial cells produces the myelin sheaths that insulate axons, or nerve fibers, in the central nervous system (CNS)? ependymal cells astrocytes microglia oligodendrocytes

oligodendrocytes

what cells form myelin sheaths in the CNS

oligodendrocytes

The myelin sheath that covers many CNS axons is formed by ependymal cells. astrocytes. microglia. satellite cells. oligodendrocytes.

oligodendrocytes.

contralateral *** not on test #5

on or relating to the opposite side (of the body) *** not on test #5

ipsilateral *** not on test #4

on or relating to the same side (of the body) *** not on test #4

how many axons does each neuron have

one but may have occasional branches

which part of the sensory neurons acts as an impulse receptor sites

only the most distal part

Gated ion channels

open and close because of some sort of stimulus, change permeability

Ligand-gated

open or close in response to ligand such as ACh binding to receptor protein

Voltage-gated

open or close in response to small voltage changes across the cell membrane

If extracellular Ca2+ concentration decreases- Na+ gates ____ and membrane ______

open, depolarizes

What are some examples of molecules and organelles moved along an axon toward its cell body?

organelles to be degraded, signal molecules, viruses, and bacterial toxins

Which of these is not one of the essential components of a reflex arc? output to upper motor neuron integration process in the CNS output to a peripheral effector receptor activation

output to upper motor neuron

When information is delivered within the CNS simultaneously by different parts of the neural pathway, the process is called ________ processing.

parallel

An individual accidentally transected the spinal cord between T1 and L1. This would result in ________. hemiplegia paraplegia spinal shock only quadriplegia

paraplegia

Which branch of the peripheral nervous system is most active during rest?

parasympathetic

caudate nucleus *** not on test #10

part of the basal ganglia, which controls voluntary behavior. *** not on test #10

Satellite cells

protect neuron cell bodies

what is the purpose of myelin

protects and electrically insulates fibres and it increases the speed of transmission of nerve impulses

function of blood-ganglia barrier

provide homeostasis of the fluid surrounding peripheral nerve cell bodies

Which of the following is not a function of astrocytes?

provide the defense for the CNS

Which of the following is not a function of astrocytes? control the chemical environment around neurons guide the migration of young neurons, synapse formation, and helping to determine capillary permeability provide the defense for the CNS support and brace neurons anchor neurons to blood vessels

provide the defense for the CNS

Neuroglia/Glia Cells

support cells of the CNS

Satellite cells and Schwann cells

supporting cells of the PNS

what are the 2 principle types of cells hat make up nervous tissue

supporting cells- neuroglia, neurons

Which of the following hypothalamic control centers would you predict is the LEAST important for survival? suprachiasmatic nucleus autonomic control center temperature control center thirst center

suprachiasmatic nucleus

Which brain nucleus is the body's "biological clock"? suprachiastmatic nucleus subthalamic nucleus dorsomedial nucleus lentiform nucleus

suprachiastmatic nucleus

what do schwann cells do

surround and form myelin sheaths around larger nerve fibres in PNS, functionally similar to oligodendrocytes

Schwann cells

surround fibers of the PNS and produce myelin sheaths. Vital to nerve regeneration

connective tissue sheathes

surround individual neurons, groups of neurons, and whole nerves

Satellite cells

surround neuron cell bodies in the PNS, function largely unknown

where are satellite cells located

surround neuron cell bodies located in PNS, same functions as astrocytes

Which general aspect of the autonomic nervous system increases cardiac output?

sympathetic

The __________ nervous system controls glandular secretion. sympathetic parasympathetic sympathetic and parasympathetic afferent

sympathetic and parasympathetic

what are the 2 subdivisions of the ANS

sympathetic division, parasympathetic division

Postganglionic fibers of the autonomic nervous system that innervate internal organs do not rejoin the spinal nerve but form sympathetic nerves. dorsal rami. gray rami. white rami. ventral rami.

sympathetic nerves.

The two branches of the autonomic nervous system are the __________ and __________.

sympathetic; parasympathetic

An impulse from one nerve cell is communicated to another nerve cell via the ________.

synapse

The site of intercellular communication between a neuron and another cell is the hillock. synaptic terminals. telodendria. synapse. collateral.

synapse.

Which of the following blocks voltage-gated sodium channels?

tetrodotoxin and lidocaine

During an epileptic seizure, the triggering of convulsions would not directly involve the uncontrolled activity of neurons located in the ______. pyramidal tracts primary motor cortex thalamus medulla oblongata

thalamus

Second-order neurons of both the specific and nonspecific ascending pathways terminate in the ________. medulla thalamus somatosensory cortex spinal cord

thalamus

Which part of the brain is considered the "gateway" to the cerebral cortex? thalamus hypothalamus mesencephalon pons

thalamus

Gap junctions

that allow graded current to flow between adjacent cells

Define Diencephalon:

the "between" brain; parts of the brain between cerebral hemispheres and the midbrain.

proprioception

the ability of the brain to know the positions of its body parts at all times

At a chemical synapse, the intensity of the stimulus is coded by

the amount of neurotransmitter released and the amount of calcium that enters the axon terminal

At a chemical synapse, the intensity of the stimulus is coded by _______.

the amount of neurotransmitter released and the amount of calcium that enters the axon terminal

When magnesium was added to the extracellular solution,

the amount of neurotransmitter released decreased

When magnesium was added to the extracellular solution, _______.

the amount of neurotransmitter released decreased

broca's area

the area in the frontal lobe, usually in one hemisphere, just anterior to the motor cortex that controls motor speech

the primary motor area

the area of the cerebral cortex that lies in the pre-central gyri & controls voluntary muscles

major parts of the brain are___

the brainstem, cerebellum, cerebrum, diencephalon are the___

lateral ventricles

the cavities within each cerebral hemisphere separated by the Septum Pellucidum ( 1 )

cervical nerve plexus C! / C4

the cervical nerves that lie & supply the muscles of the neck & skin

Sensory transduction is defined as

the conversion of a stimulus to a change in membrane potential

longitudinal fissure

the deep groove that separates the left & right hemispheres

Which criterion is used to functionally classify neurons?

the direction in which the nerve impulse travels relative to the central nervous system

Which criterion is used to functionally classify neurons? the number of processes extending from the cell body neuron whether the nerve fibers are myelinated or unmyelinated the direction in which the nerve impulse travels relative to the central nervous system whether the neurons are found within the CNS or the PNS

the direction in which the nerve impulse travels relative to the central nervous system

Cell bodies of the sensory neurons of the spinal nerves are located in ________. sympathetic ganglia the thalamus the dorsal root ganglia of the spinal cord the ventral root ganglia of the spinal cord

the dorsal root ganglia of the spinal cord

The subdural space lies between the arachnoid mater and the pia mater. the endosteum and the periosteum. the pia mater and the subarachnoid space. the dura mater and the arachnoid mater. the pia mater and the dura mater.

the dura mater and the arachnoid mater

Imagine you changed the concentration of K+ outside a neuron such that the resting membrane potential changed to -80 mV (from the normal resting value of -70 mV). What have you changed?

the electrical gradient for K+ and the concentration gradient for K+

dura mater

the outermost, toughest layer of the three meninges covering the brain and spinal cord ( 15 )

If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur, except the membrane will slowly lose its capacity to generate action potentials. the intracellular concentration of sodium ions will increase. the neuron will slowly depolarize. the inside of the membrane will have a resting potential that is more positive than normal. the intracellular concentration of potassium ions will ncrease.

the intracellular concentration of potassium ions will increase.

The time interval for conduction would be shortest with

the largest and most heavily myelinated axons

The time interval for conduction would be shortest with,

the largest and most heavily myelinated axons

cerebral cortex

the layer of gray matter that makes up the outermost portion of the cerebrum, making up 75% of all neuron in the nervous system

What are the cerebral hemispheres?

the left and right halves of the cerebrum.

cerebrospinal fluid

the liquid secreted by choroid plexus that circulates in spaces in the brain, in subarachnoid spaces of meninges, ventricles & central canal; Cushions, brings in nutrients, and helps maintain stable ion concentration in CNS

parietal lobe

the lobe of the brain that Interprets sensations such as pain, pressure, touch ,hot and cold. (green area)

A second nerve impulse cannot be generated until ________.

the membrane potential has been reestablished

A second nerve impulse cannot be generated until ________. the Na ions have been pumped back into the cell proteins have been resynthesized the membrane potential has been reestablished all sodium gates are closed

the membrane potential has been reestablished

Which stimulus was at or above threshold?

the moderate and strong stimuli

If the axon terminal of a motor neuron suddenly became permeable to calcium ion, neurotransmitter release will be blocked. the motor end plate will be hyperpolarized. the motor end plate will be depolarized. the neuron will become unable to stimulate the muscle cell. the neuron will fire an action potential.

the motor end plate will be depolarized.

Saltatory conduction is made possible by ________.

the myelin sheath

third ventricle

the narrow space at the midline of the brain beneath the corpus callosum & filled with CSF ( 3 )

brachial plexus nerves C5 / T1

the nerves that supply ulnar, radial, & axillary nerves

In a myelinated axon, how do the nodes of Ranvier differ from other segments of the same axon?

the nodes are more permeable to ions

Which criterion is used to structurally classify neurons?

the number of processes extending from their cell body

Acetylcholine binds to its receptor in the sarcolemma and triggers __________.

the opening of ligand-gated cation channels

The repolarization phase of an action potential results from __________.

the opening of voltage-gated K+ channels

A neuron that receives neurotransmitter from another neuron is called the postsynaptic neuron. an oligodendrocyte. an interneuron. the motor neuron. the presynaptic neuron.

the postsynaptic neuron.

If a signal from a sending neuron makes the receiving neuron more negative inside,

the receiving neuron is less likely to generate an action potential.

If a signal from a sending neuron makes the receiving neuron more negative inside, the receiving neuron is less likely to generate an action potential. the sending neuron becomes more negative inside. the sending neuron becomes more positive inside. the receiving neuron is more likely to generate an action potential. the receiving neuron immediately generates an action potential.

the receiving neuron is less likely to generate an action potential.

The frequency of action potentials is

the reciprocal of the interspike interval, and measured in Herz

what are Nissl bodies

the rough ER in a neuron

In this activity, the stimulus voltage used was

the same for all of the axons and suprathreshold for all of the axons

In this activity, the stimulus voltage used was _______.

the same for all of the axons and suprathreshold for all of the axons

sulci

the shallow grooves located on the cerebral cortex, between the gyri

In a neuron, sodium and potassium concentrations are maintained by the sodium-potassium exchange pump such that __________.

the sodium concentration is higher outside the cell than inside the cell and the potassium concentration is higher inside the cell than outside the cell.

Which of the following allows us to consciously control our skeletal muscles?

the somatic nervous system

Which of the following allows us to consciously control our skeletal muscles? the afferent division of the nervous system the somatic nervous system the sympathetic division of the autonomic nervous system the parasympathetic division of the autonomic nervous system

the somatic nervous system

subarachnoid space

the space between the pia mater & the arachnoid membrane filled with CSF. ( 13 )

During the relative refractory period

the stimulus must be above threshold to generate action potential

What is the electrochemical gradient of an ion?

the sum of the electrical and chemical gradients for that ion

What is the electrochemical gradient of an ion?

the sum of the electrical and concentration gradients for that ion

Sympathetic preganglionic cell bodies are located in the __________ and __________ regions of the spinal cord.

thoracic; lumbar

The minimum voltage that is required to generate an action potential is called the _______.

threshold voltage

The minimum voltage that is required to generate and action potential is called the

threshold voltage

integration

to process and interpret sensory input and decide if an action is needed

Which of the following is NOT a function of the myelin sheath?

to recapture and recycle released neurotransmitters

Potential difference

unequal distribution of charge exists between the immediate inside and immediate outside of the plasma membrane: -70 to -90 mV

In a(n) ________ neuron, the dendrites and axon are continuous or fused. unipolar interneuron anaxonic bipolar multipolar

unipolar

Neurons in which dendritic and axonal processes are continuous and the soma lies off to one side are called tripolar. multipolar. bipolar. unipolar. anaxonic.

unipolar.

Sensory neurons of the PNS are bipolar. unipolar. anaxonic. multipolar. tripolar.

unipolar.

Gray matter

unmyelinated axons, cell bodies, dendrites, neuroglia. Integrative functions

Gray matter

unmyelinated fibers (mainly cell bodies)

Spastic paralysis suggests involvement of the ________. spinal nerve roots lower motor neurons neuromotor junction upper motor neurons

upper motor neurons

frontal lobes of the brain

used for reasoning, emotions, judgement, and voluntary movements. (blue area)

what is in the soma/perikaryon

usual organelles

nerve fiber

usually refers to axons

The ________ innervates the ventrolateral body surface, structures in the body wall, and the limbs. ventral ramus white rami communicantes gray rami communicantes dorsal ramus dermatomes

ventral ramus

Nerve tracts or fasciculi make up the central canal. gray commissures. posterior gray horns. white columns. anterior gray horns.

white columns.

The preganglionic fibers that connect a spinal nerve with an autonomic ganglion in the thoracic and lumbar region of the spinal cord and carries visceral motor fibers that are myelinated form the dermatomes. ventral ramus. gray rami communicantes. dorsal ramus. white rami communicantes.

white rami communicantes.

what is a myelin sheath

whitish fatty segmented sheath that covers nerve fibres long or large in diametre

neuron

whole nerve cell

Most CNS neurons lack centrioles. This observation explains the ability of neurons to generate an action potential. the ability of neurons to communicate with each other. the ability of neurons to produce a resting potential. why CNS neurons grow such long axons. why CNS neurons cannot divide to regenerate damaged tissue.

why CNS neurons cannot divide to regenerate damaged tissue.

Which of the following is not true about a positive Babinski reflex? flaring of the toes when the sole is stroked a sign of injury to descending spinal tracts normal in newborns why you close your eyes when you sneeze abnormal in adults

why you close your eyes when you sneeze

If an increase in extracellular potassium depolarizes a neuron, which of the following would be correct?

would change the membrane potential to a less negative value.

what do oligodendrocytes do

wrap processes tightly around fibres producing insulating coverings called myeline sheaths

is the functional and anatomical organization of sensory processing networks hierarchical?

yes, the lower the neuron on the spine, the lower the order, the head has a 3rd order neuron where as the sacral region has a 1st order neuron

How are spinal nerves named? Give an example:

~ According to level where they arise. - Ex: C5 - arises from cord beneath 5th cervical vertebra.

Where is the cerebrum's primary somatic motor area? What is controlled from this area?

~ Precentral Gyrus - mechanisms controlling voluntary movement

What can produce a synaptic change and what does that change facilitate?

~ Repeated impulses over a neuronal circuit. - The change facilitaes (in theory): 1) an increase in the number of presynaptic axon terminals or 2) an increase in the number of receptor proteins in the postsynaptic neuron's membrane.

What are 2 types of memory and what is the difference between the two?

~ Short term and long term memory. - Short term memory involves the storage of information for a few seconds to a few minutes. - Long term memory involves the storage of information for days to years.

What is cerebral palsy and what are some of its causes?

~ permanant, non-progressive damage to motor control areas of the brain. - Possible causes: prenatal infecctions; mechanical trauma to the head beforem during, or after birth; reduced oxygen supply.