Physiology- Chapters 8, 9, 10, & 11.

pia mater

"delicate" inner layer covering the brain

dura mater

"tough mother" outermost covering of the brain

kinesins and dyneins

(2) contractile microtubules that are responsible for axonal transport

perikaryon

(other than soma) a name for the cell body of a neuron

leak potassium channels

(specific) ion channels that are open and allow K+ to move down its concentration gradient OUT OF THE CELL; primarily responsible for generating resting potential (this is the reason the inside of the cell is negative relative to the outside at rest)

interneurons

(within the CNS only) neurons that receive signal from sensory neurons, pass impulse to other interneurons, eventually to motor neurons

The autonomic nervous system is involved in which of the following actions?

- Fight or flight - Pupil dilation or constriction - Urination - Swallowing

Symptoms of diabetic neuropathy that involve the autonomic nervous system may include __________.

- Urinary incontinence - Erectile disfunction - Lack of awareness of hypoglycaemia - Urinary incontinence

Temporal Summation

1 neuron with 2 AP's fire close in time to trigger potential, arrive same place same time and add together

The nervous system consists of 2 parts

1) CNS (Central Nervous system)- The brain and the Spinal cord. 2) PNS (Peripheral Nervous System)- The nerves outside the CNS)

Synaptic Events

1. action potential depolarizes axon terminal 2. Ca2+ open and go in 3. Ca2+ triggers exocytosis of NT 4.NT diffuses across synapse 5. Post cell responds

__ paired cranial nerves serve the __ and __.

12; head; neck

Action Potential

2 Na+, 1 K+ gate stimulus depolarized and activation gate opens, Na enters, peak, K opens and leaves, repolarizes and back to original

How many molecules of ACh are necessary to completely activate the ACh receptor?

2.

Spatial Summation

3 EPSP neurons, arrive at same time to different locations and when added together make AP

__ pairs of __ nerves arise from the spinal cord and exit between __ to serve the __ body.

31; spinal; vertebrae; lower

support and protect neurons, provide nutrients and oxygen, insulate with myelin, and protect by destroying pathogens

4 functions of glial cells

Glial Cells

90%, support for neurons

The reticular formation is a network of neurons found along the brain stem. Many of the functions of the reticular formation are widespread as a result. Which of the following would occur if you were to disrupt the functions of the reticular formation?

A person would have a difficult time waking due to an inability to arouse the brain.

Most neurons have at least two processes extending from the soma, or cell body. Which type of neuron only has one process extending from the cell body?

A pseudounipolar neuron.

Define "refractory period."

A second stimulus will not produce an APot, like squeezing a trigger

What is the scheme of synaptic transmission?

AP in afferent opens gates for Ca in axon terminal and Ca enters; Ca triggers pre-made neurotransmitter (NT) to dock, fuse and release contents in synaptic cleft; NT binds to receptors on efferent cell membrane; binding of receptor opens or closes gates for specific ions; ion flow changes, initiating a GP; GP either causes depolarization or hyperpolarization; NT enzymatically broken down and shipped back to afferent axon terminal to be recycled

Heuristics problem: Any kind of stimulus can cause __ if sufficiently __, causing __ activation.

APs; strong;accidental

What is the trigger for ACh into the synaptic cleft of a neuromuscular junction?

Acetylcholinesterase opens vesicles allowing ACh to diffuse into the cleft.

Information coming into the central nervous system is transmitted along _______ neurons.

Afferent and sensory.

Which of the following choices best describes the path of sensory information from the receptor into the spinal cord?

Afferent neuron to dorsal root ganglion to dorsal horn.

Information arriving at the central nervous system is referred to as __________.

Afferent.

Sensory neurons are also called __________ neurons because they transmit information toward the central nervous system.

Afferent.

Which of the following is the type of adrenergic receptor found in most sympathetic target tissues?

Alpha 1.

What happens if a graded stimulus is of sufficient strength to reach threshold at the trigger zone?

An action potential occurs.

Describe the concept of resting membrane potential:

An electrical gradient that exists between the intracellular and extracellular fluids.

What best describes the resting membrane potential?

An electrical gradient that exists between the intracellular and extracellular fluids.

Interneurons __________.

Are located entirely within the CNS.

Which nervous system division has parasympathetic and sympathetic branches?

Autonomic division of the efferent nervous system.

The sympathetic and parasympathetic nervous systems are divisions of which system?

Autonomic nervous system.

The division of the efferent nervous system that controls smooth and cardiac muscles and many glands is the _______ division.

Autonomic.

Which of the following best describes the direction and function of efferent signals?

Away from the central nervous system, cause motor effects in gland or muscles.

What is myelin? What is its function?

Axons are covered in myelin (protein/lipid), Insulates and speeds signal. Prevents leakage of current. Myelinated = 150 m/sec Unmyelinated = 1 m/sec

What specific tissue makes up the corpus callosum?

Axons.

The two cells below are hypothetical cells with a concentration of 100 mOsm of K+ inside the cells and containing only leak channels for K+ within the membrane. Each cell is placed into a different solution containing different concentrations of K+ in the extracellular fluid. Which of the two cells below has a higher permeability to K+ and why? A) A and B would have the same amount of permeability. B) B, because it has more ion leak channels for K+ than A. C) A, because it has a greater concentration gradient that B. D) There is not enough information to tell.

B) B, because it has more ion leak channels for K+ than A.

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, A) ion channels in the plasma membrane of the sending neuron open. B) ion channels in the plasma membrane of the receiving neuron open. C) vesicles in the synaptic terminal fuse to the plasma membrane of the sending neuron. D) the receiving neuron becomes more negative inside. E) the receiving neuron becomes more positive inside.

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

Which of the following statements best describes the concept of permeability? A) the rate at which a molecule crosses the membrane B) the ability of a molecule to cross the cell membrane C) the surface area of a cell and its relationship to the diffusion of water D) whether or not a molecule moves across the cell via passive or active mechanisms

B) the ability of a molecule to cross the cell membrane

Which type(s) of taste molecules (tastants) block potassium channels leading to depolarization of the cell?

Bitter.

The neurotoxin called tetrodotoxin, or TTX, __________.

Blocks voltage-gated sodium channels.

The part of the brain anatomically most similar to the spinal cord is the?

Brain Stem.

Most of the cranial nerves originate in the?

Brain stem

Which of the following are components of the central nervous system? - Autonomic neurons - Brain - Somatic motor neurons - Spinal cord - Cranial nerves

Brain, Spinal cord.

Why is an action potential conducted in only one direction, from an axon hillock to an axon terminal? A) The number of voltage-gated ion channels increases along the length of the axon. B) The channels are progressively easier to open down the length of the axon. C) The membrane channels upstream are refractory and cannot open. D) Second messengers activate channels sequentially.

C) The membrane channels upstream are refractory and cannot open.

Which of the following statements best describes the resting membrane potential? A) a concentration gradient that exists between the intracellular and extracellular fluids B) the differences that exist between excitable cells and nonexcitable cells C) an electrical gradient that exists between the intracellular and extracellular fluids D) an osmotic pressure difference that exists between the intracellular and extracellular fluids

C) an electrical gradient that exists between the intracellular and extracellular fluids

Put the following structures involved in the neural pathway for sound in the correct order, starting from the inner ear: a. cochlear nucleus b. afferent neuron c. hair cell d. auditory cortex e. medial geniculate body

C, B, A, E, D.

Are nuclei in the CNS or PNS?

CNS

Are tracts in the CNS or PNS?

CNS

Is the brain part of the ANS or CNS?

CNS

The sensory neurons of the ANS carry info to the __.

CNS

Two divisions on the Nervous System

CNS & PNS

includes the brain and spinal cord

CNS (central)

What ions trigger pre-made vesicles of NT to dock, fuse and release contents into the synaptic cleft?

Ca

In contrast to almost all other cell types in the body, neurons __________.

Can change their membrane potential and the permeability of their plasma membranes.

Which substances can cross the blood-brain barrier by simple diffusion?

Carbon dioxide, ethanol, and estrogen.

Which of the following is/are targets of the efferent nervous system?

Cardiac muscle, glands, smooth muscle, skeletal muscle.

The ________ is a salty fluid continuously secreted into hollow cavities known as ________. This fluid is secreted into these cavities by the _______, a specialized tissue consisting of capillaries and transport epithelium.

Cerebrospinal fluid, ventricles, choroid plexus.

From superior to inferior, which of the following lists is the correct anatomical arrangement of the components of the central nervous system?

Cerebrum, diencephalon, midbrain, pons, medulla oblongata.

What starts an action potential?

Chemicals (Neurotransmitters, acids, bases) Mechanical or electrical stimulation Stimulation opens Na+ channels, so Na+ rushes in, depolarizes membrane, which opens more voltage sensitive Na+ channels. Initiated at the axon hillock (most voltage gated) In sensory neurons—in sensory nerve endings

What type of receptor would be sensitive to changes in the oxygen concentration or pH of the blood?

Chemoreceptors.

The Nervous System is:

Complex, billions of neurons and brain cells. The brain, cranial nerves, spinal cord, spinal nerves, ganglia, enteric plexuses in gut and sensory receptors.

What type of conduction takes place in unmyelinated axons?

Continuous conduction.

Which structure allows communication between the two hemispheres of the brain?

Corpus callosum.

Put the following structures in the correct order, as visual information moves from the retina to the brain: a) optic chiasm b) visual cortex c) optic radiations d) ganglion cells e) optic nerve f) lateral geniculate body

D, E, A, F, C, B.

The part of the neuron that receives most of the incoming signals is the?

Dendrite.

The gray matter of the central nervous system contains mainly ________ and is located ___________ of the spinal cord.

Dendrites, axon terminals, and cell bodies of neurons; in the central portion.

What do the terms "depolarization," "repolarization," and "hyperpolarization" mean?

Depolarization = a potential less negative than the resting potential (more positive = +35) Repolarization = goes back towards original polarized state (+35 to -70) Hyperpolarization = a potential more negative than at rest (underswing -70 to 90 mv)

What would happen to the membrane potential if a cell suddenly becomes more permeable to Na+?

Depolarize.

__________ light from objects reaching our retinas is perceived.

Emitted, reflected, and refracted.

What is the collection of neurons in the walls of the digestive system called?

Enteric nervous system.

The membrane potential at which the electrochemical force on an ion = 0 is called the __________ potential for that ion.

Equilibrium.

EPSP

Excitatory Postsynaptic Potential -adds+ charges, depolarizes, need more than one to get AP

Neurotransmitters are usually released into synapses by?

Exocytosis.

What causes the depolarization? What channels are open/closed? What ions are moving in or out of the cell?

Fast Na gates = open Slow gated Na = starting to slowly close Slow gated K channels = closed, received signal to open membrane permeable to Na and rushes IN down concentration gradient.

The basal ganglia (nuclei) play an important role in controlling movement. They are located in the ___________.

Forebrain.

A high-pitched sound is also a high-__________ sound.

Frequency.

The binding of acetylcholine to muscarinic receptors causes __________.

G protein activation.

The neurocrine that acts as the main inhibitory neurotransmitter in the brain is __________.

Gamma-aminobutyric acid.

Outside the central nervous system, clusters of neuron cell bodies are called __________, and axons travel together in bundles called __________.

Ganglia; nerves.

The brain consumes about half of the _______ circulating in the body.

Glucose.

The two types of electrical signals transmitted through neurons are __________.

Graded potentials and action potentials.

Which of the following structures is/are associated with hearing?

Helicotrema.

Action potentials propagate down the axon __________.

Like a row of falling dominoes, by current flow through the intra- and extracellular fluid around sequential areas of axonal membrane, and by current flow through electronic conduction.

Demyelinated Disease

Multiple sclerosis: tired, bad vision and walking

What would the effect of ACh binding to its receptor on the postsynaptic muscle cell?

Na+ would flow into the cell and K+ would flow out of the cell.

Which type of receptors are found in the neuromuscular junction?

Nicotinic.

The somatic nervous system and the parasympathetic nervous sytem both release acetylcholine onto their target tissues. Do you predict that this would indicate that these two pathways carry out the same effects? Why or why not?

No, because the receptors found on the target tissue for each pathway are different.

The perception of scalding hot water on the skin may involve which types of receptors?

Nociceptors and cold receptors.

What is found in the cell body? What is the function of the cell body?

Nucleus, it keeps the cell alive

The myelin sheaths that surround axons in the CNS are formed by __________.

Oligodendrocytes.

Which glial cell produces myelin in the central nervous system?

Oligodendrocytes.

Neurons that innervate smooth muscle (such as the lining of blood vessels or the GI tract) belong to the __________ nervous system.

Peripheral and autonomic.

The innermost layer of meninges, resting directly on the nervous tissue, is called the _________.

Pia mater.

During the after-hyperpolarization phase of the action potential, __________.

Potassium channels are closing.

Which of the following would NOT cause the membrane potential to change from -70 mV to +30 mV? Potassium ions leaving the cell. Calcium ions entering the cell. Sodium ions entering the cell. Chloride ions leaving the cell.

Potassium ions leaving the cell.

The resting membrane potential of a cell is produced by ion movements through __________.

Potassium leak channels and sodium leak channels.

Modulation of Synaptic Activity

Prefacilitation (increase release) and Preinhibition (decrease release)

Which of the following cell types or structures can be found in both the sympathetic and the parasympathetic nervous system?

Preganglionic neurons and chain ganglia.

Which of these characteristics is the same in both the sympathetic and parasympathetic branches for the vast majority of neurons?

Preganglionic neurotransmitter.

What is a membrane potential? (What does the term mean?)

Resting Membrane Potential = difference in electrical charge between the inside of the neuron and the outside of the neuron

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.

Nervous System functions

Sensory- detect stimuli (internal, external) Intergrative- sensory info- analysis, storage, decisions. (Can be physical action) Motor- effector functions eg muscle, glands

Which of the following neurons or groups of neurons are NOT considered to be a part of the efferent pathway?

Sensory.

__________ neurons, from the afferent division of the PNS, receive information from the body and transmit that information to an integrating center in the __________.

Sensory; CNS.

The target tissue of somatic motor neurons is?

Skeletal muscle.

Somatic motor neurons control A)skeletal, cardiac, and smooth muscles. B)skeletal muscles. C)skeletal and cardiac muscles. D)smooth muscles, adipose tissue and glands.

Skeletal muscles.

Somatic motor neurons control:

Skeletal muscles.

Somatic motor neurons control?

Skeletal muscles.

Action potential conduction velocity is the slowest in __________.

Small unmyelinated axons.

The cells that we are capable of controlling consciously are the

Somatic Motor Neurons.

The cells that we are capable of controlling consciously are the _____ neurons.

Somatic motor (somatic efferent).

The cells that we are capable of controlling consciously are the _____ neurons. A)sympathetic B)somatic motor (somatic efferent) C)parasympathetic D)somatic sensory (somatic afferent)

Somatic motor (somatic efferent).

These neurons secrete the neurotransmitter acetylcholine onto their targets?

Somatic motor and parasympathetic motor.

Which of the following are components of the efferent nervous system?

Somatic motor neurons, parasympathetic neurons & sympathetic neurons.

The portion of the nervous system that directly controls skeletal muscles is the __________.

Somatic motor system.

A single neuron is stimulated at the central nervous system; this signal travels all the way to the target tissue, where the neurotransmitter acetylcholine is released onto the target tissue. The acetylcholine binds to a nicotinic receptor to induce skeletal muscle contraction. These steps describe the function of which branch of the efferent nervous system?

Somatic.

Graded potentials __________.

Spread through electronic conduction, can summate, and can be depolarizing or hyper polarizing.

Through which layer of the meninges does cerebrospinal fluid run?

Subarachnoid space.

During strenuous exercise, which of the following are likely to be more active?

Sympathetic nervous system and somatic nervous system.

The motor neurons primarily associated with the fight-or-flight responses are the _____ neurons.

Sympathetic.

The diameter of blood vessels varies under the control of _______ neurons, which cause the diameter to _______.

Sympathetic; either increase or decrease, depending upon the type of receptor present.

The small space between the sending neuron and the receiving neuron is the vesicle. synaptic cleft. synaptic terminal. neurotransmitter. calcium channel.

Synaptic cleft.

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

Synaptic cleft.

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

Synaptic cleft.

-5, -10

THE MAGNITUDE OF THE RESTING MEMBRANE POTENTIAL VARIES BETWEEN ____ to ____ mV FROM CELL TO CELL

GHK

The ______ equation is essentially an expanded version of the Nernst equation that takes into consideration the individual ion permeabilities

Describe the concept of permeability:

The ability of a molecule to cross the cell membrane

What are the two major components of the central nervous system?

The brain and spinal cord.

Gross structure of the CNS

The brain consits of 3 major parts: 1) Cerebrum and diencephalon 2) Brainstem (midbrain, pon, medulla) 3) Cerebellum

Which part of the nervous system is the most different when comparing humans to other animals?

The cerebrum.

Which of these structures consists exclusively of white matter and connects the cerebral hemispheres?

The corpus callosum.

Ohm's law

The effect of voltage (V) and resistance (R) on current (I): I = V/R

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.

Brain ventricles develop from

The lumen of the neural tube.

What characterizes depolarization, the first phase of the action potential?

The membrane potential changes from a negative value to a positive value.

Which of the following is an example of antagonistic control?

The parasympathetic stimulation causes bronchoconstriction while sympathetic stimulation causes bronchodilation.

What part of the brain helps to provide regulation of breathing?

The pons.

What part of the brain provides a relay station between the cerebrum and the cerebellum?

The pons.

The amplitude of the peak of the action potential depends on __________.

The relative sizes of the electrochemical gradients for Na+ and K+ and the differences in Na+ and K+ permeability.

Action potentials are unidirectional. Why do they travel only from the cell body of a neuron to the terminal and never go backward?

The sodium channel inactivation gates close once an action potential passes.

When calcium ions enter the synaptic terminal,

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

How do these ions cross the membrane? In what direction do they go (at rest) and why?

They cross the membrane through pores down the concentration gradient at rest. They do this to fill out the concentration gradient and because charges that differ within and out of the cell.

The total amount of neurotransmitter released at the axon terminal is directly related to the __________.

Total number of action potentials.

The site of information integration in a neuron is the __________.

Trigger zone.

Motor fibers leave the spinal cord's gray matter via this?

Ventral root.

The term "fast axonal transport" refers to __________.

Vesicular transport of proteins and organelles down the axon.

The types of channels that can be found in excitable cells such as neurons include __________.

Voltage-gated, Ligand-gated, Leak.

One cranial nerve, Cranial __, the __ nerve, serves the __.

X; Vagus; viscera

Relative Refractory

XLG stimulus to get action, hyperpolarization

If the Na+/K+ ATPase were turned off, the membrane potential would eventually become equal to __________.

Zero mV.

Sodium, Potassium

_____ and _____ (ions) PLAY THE MOST IMPORTANT ROLES IN GENERATING THE RESTING MEMBRANE POTENTIAL

Activation of the parasympathetic nervous system produces __________.

accommodation.

What are particularly important NTs?

acetylcholine (ACh); norepinephrine (NorE)

Drugs to treat asthma attacks might include __________.

alpha agonists and beta agonists.

Absolute Refractory

another potential cant be generated repolarzation

temporal

area of cerebrum responsible for hearing; interpreting visual scenes, sensory experiences, music, patterns

occipital

area of cerebrum responsible for vision and recognition

parietal

area of cerebrum that processes senses, understanding speech, and using words to express feelings and thought

interneuron

association neurons that lie within brain and spinal chord; transmit impulses within brain and spinal chord

The type of glial cells that modulate and maintain synaptic activity is(are) __________.

astrocytes.

What is the resting membrane potential? (give a number)

between -65 and -70 mv

What is the single most important organ of sensation?

brain

Central nervous system

brain + spinal cord; contains all parts of interneurons

CNS

brain and spinal cord: receives input and sends output

The central nervous system (CNS) consists of the __________ and the __________.

brain; spinal cord.

varicosities

bulges along the length of some axons where neurotransmitters are released

Myelinated processes __ conduct APs.

can't

medulla oblongata

cardiac center, respiratory center, vasomotor center, swallowing, coughing, sneezing, hiccuping, vomiting

The autonomic nervous system innervates __________.

cardiac muscle, blood vessels, and adipose tissue.

What is the function of the axon?

carries information as an action potential (electrical signal, change in electrical potential). Information read at the origin of the axon.

efferent

carries motor commands from CNS (division of PNS)

thalamus

central relay station for sensory impulses (except smell); interpretation of pain, temperature, light, touch, and pressure

What part of the brain is especially important for sensation?

cerebral cortex

The lens focuses light on the photoreceptor cells by __________.

changing shape: rounding up or flattening out.

What are the six types of receptor cells?

chemo; mechano; noci; osmo; photo; thermo

The sympathetic nervous system can exert effects on specific organs via the __________.

collateral ganglia.

The sympathetic nervous system can exert effects on specific target organs via the __________.

collateral ganglia.

midbrain

controls movements of head/legs to visual stimuli or head/trunk to auditory stimuli

iris

controls the amount of light passing through pupil; colored part of eye

Within the retina __________.

convergence of synaptic input is greater at the periphery of the retina and ganglion cells can detect color and contrast (center versus surround).

cerebellum

coordinates (not initiates) voluntary motor action; coordination, posture; damage results in tremors, inaccurate movement, loss of muscle tone

The cerebellum receives input from the __________.

cortex, spinal cord, and the basal nuclei.

sensorineural deafness

damage to cochlea, auditory nerve, or auditory nerve pathways; can be caused by loud sounds, tumors in CNS, brain damage, or use of certain drugs (aka nerve deafness)

glaucoma

damage to the optic nerve usually caused by intraocular pressure

pupil

dark center of eye which lets light into eye

increase axon diameter

decreases cytoplasmic resistance

What is the stimulus for mechanoreceptors? General design? Examples?

deformation of cell membrane; ions leak when cell membrane is bent; hair cells, baroreceptors (blood pressure); proprioceptors (body position), touch and pressure receptors

afferent

delivers sensory information to CNS (division of PNS)

Where are the efferent (receiving) sides of synapses?

dendrites; cell bodies

retina

detects light and forms image for transmission to the brain; back of the eye; site of rods and cones

What 2 forces influence movement of ions across the plasma membrane?

diffusion and electrostatic pressure Diffusion (concentration gradient) - things move from high to low concentration, ions distribute evenly high to low. Electricity - Electrolytes - NaCl = Na+ + Cl- (ions = electrically charged particles)

colaterals

distal branches that come off of the axon

afferent and efferent

divisions of PNS

The ganglia of the ANS include the __ __ ganglia of the spinal cord and contain the __ __ of some __ neurons and allow for some __ of info.

dorsal root; cell bodies; sensory; sorting

retrograde

dyneins are responsible for (afferent) _________ movements--toward the cell body

Are motor processes afferent or efferent?

efferent

What cell has receptors the neurotransmitters bind to?

efferent

receiving, in terms of synapses

efferent

axons

efferent fibers--transmit impulse away from cell body

motor neuron

efferent neuron that carries nerve impulses out of brain and spinal chord

What does it mean that an action potential is "all or none"?

either you have one or don't, depolarizations of less than a difference if -15 mv wont lead to AP

With referred pain, activation of the sensory nerve is interpreted as coming from the receptors at the __ of the neural pathway, even if the AP actually started __ __ the pathway.

end; farther up

Where are the afferent (sending) sides of synapses?

ends of axons

A given NT can be __ at one synapse and __ at a different synapse.

excitable; inhibitory

Presynaptic Modulation

excitatory neuron fires and AP generated, gets released at 2 axons but IPSP stops 3rd

depolarization in synaptic transmission

excitatory post-synaptic potential

Each synapse is either __ or __; it doesn't __.

excitatory; inhibitory; switch

hyperopia

farsightedness

aqueous humor

fills the anterior cavity; helps keep shape, refracts light, maintains pressure; located between cornea and lens

vitreous humor

fills the posterior cavity; keeps retina firmly pressed against choroid

gyri

folds in the cerebrum

semicircular canals

functions in equilibrium

lumps of neuron cell bodies in the PNS; gray matter

ganglia

What are found in the PNS (ganglia, nerves, nuclei, tracts)?

ganglia; nerves

What are the two types of clumps of cell bodies?

ganglia; nuclei

nodes of Ranvier

gaps in myelin sheath

Are nuclei gray or white matter?

gray

slow, short, integration tasks; type of matter

gray

sulci

grooves in the cerebrum

nerves

groups of afferent and efferent nerve fibers (in the PNS)

nuclei

groups of nerve cell bodies (in the CNS)

ganglia

groups of nerve cell bodies (in the PNS)

Nodes of Ranvier

indentations within adjacent glial cells

hyperpolarization in synaptic transmission

inhibitory post-synaptic potential

oligodendrocytes

insulating cells that form myelin sheaths in the CNS

Schwann cells

insulating cells that form myelin sheaths in the PNS

Gray matter is primarily used for __ tasks: thinking, coordinating,etc.

integration

Most gray matter is in __ areas: __ and __.

integration; nuclei; ganglia

conductive deafness

interference with transmission of vibrations to inner ear; due to plugging of external auditory meatus or changes in eardrum or auditory ossicles (aka anatomical deafness)

The vestibular nuclei receive input from the __________.

joint position receptors, visual system, and somatosensory system.

anterograde

kinesins are responsible for (efferent) _________ movements--from cell body toward axon terminals

The specific neural pathways that transmit information pertaining to a specific sensory modality are called __________.

labeled lines.

In order from superior to inferior, the ventricular system consists of the __________.

lateral ventricles, third ventricle, fourth ventricle, central canal.

What is the stimulus for photoreceptors? General design? Examples?

light; pigments absorb light and break it down causing GP; rods and cones

action potentials

long distance signals

Why is the nerve cell negatively charged at rest? What 3 factors make it so? (the 3 P's) a. Pump = 3 Na out for every 2 K in b. Protein and Phosphates = negatively charged and trapped in cell c. Permeability = more K channels are open so more K leaks out than Na leaks in =====So we have a concentration difference

lots of K+ IN, Na+ OUT

In most cells, the concentration of ions contributing to the membrane potential are ______ in the intracellular fluid compared to the extracellelular fluid, with the exception of _______ ions.

lower; potassium.

Sympathetic preganglionic neurons emerge from the __________ portion of the spinal cord.

lumbar and thoracic.

diencephalon

made up of thalamus and hypothalamus

middle ear

made up of tympanic cavity and auditory ossicles

oligodendrocytes

maintain cellular organization within grey matter and provide a myelin sheath in white matter

sclera

maintains shape of eye and protects; makes up white of the eye; goes around entire eye

Convergence

many to single

The three layers of membrane that lie between the bones and tissues of the central nervous system are called the __________. The __________ is the thick layer.

meninges; dura mater.

How do you demonstrate the strength of stimulus given that APs don't change size?

more APs

frontal

motor area of cerebrum responsible for limps, speech, movement of eyes and eyelids, problem solving

efferent neurons

motor neurons--carry signals from CNS to effector molecules in the PNS

current

movement of electrical charge (measured in amps)

ciliary bodies

muscles which control the size of the iris and pupil

White matter is nervous tissue made up of processes that are protected by __.

myelin

lipid; found in high amounts in the support cells that wrap themselves around the processes

myelin

myopia

nearsightedness

bundles of processes running together in the PNS; white matter

nerves

What are myelinated often (ganglia, nerves, nuclei, tracts)?

nerves; tracts

What are the two types of axons and dendrites?

nerves; tracts

Gray matter is nervous tissue made up of __ __ __ and __ processes (axons and dendrites) that conduct __ over __ distances.

neuron cell bodies; uninsulated; slowly; short

Some receptor cells are themselves __. In these, the GP causes an __ which travels along the __ toward the __.

neurons; AP; dendrite; CNS

Because afferent and efferent cells do not touch at the synapse, __ released from the afferent cell diffuse across the __ __, bind to __ on the efferent cell membrane, causing the response.

neurotransmitters; synaptic cleft; receptors

Are neurons likely to be replaced in adults?

no

Are receptor cells excitable?

no

Can neurons do mitosis?

no

Can synapses switch between excitatory and inhibitory?

no

Can synapses use more than one NT?

no

Do cell membranes of afferent and efferent cells touch at the synapse?

no

What causes the repolarization? What channels are open/closed? What ions are moving in or out of the cell?

no more Na in inactivation gate, so less + charges, reverts to less negative state, K+ ions are moving out the cell Fast Na channel = open Slow Na channel= closed Slow K channel = opens

__ are designed to report on painful stimuli but any other kind of receptor can also can also produce a sensation of pain as well because __ activation of other kinds of receptors is interpreted to mean __ and __.

nociceptors; strong; strong stimulus; pain (i.e., looking at the sun, bright light and pain)

small gaps that separate myelinated regions of processes

nodes of Ranvier

What is the stimulus of osmoreceptors? General design? Examples?

osmolarity of body fluids; not known; osmoreceptors

pinna

outer, funnel-like structure; collects sound waves traveling through the air (also known as the auricle)

Muscarinic receptors are located on __________.

parasympathetic target organs.

body

part of the nerve that contains a large nucleus with a prominent nucleolus

axon

part of the nerve that is a long cytoplasmic process capable of propagating an electrical impulse

in this kind of perception the same stimulus may be perceived differently depending on how long it has been going on and what stimuli were like in recent history

phasic

when a stimulus is maintained at a constant strength, but the perception of it decreases over time

phasic

What is the stimulus for chemoreceptors? General design? Examples?

presence of particular chemical; chemical-gated ion channels; receptors for smell, taste, blood values (pH, glucose, etc.)

axonal transport

process in which materials and organelles are moved along the length of the axons

where neurons reach out extensions to contact other cells

processes

axon hillock

proximal portion of axon where impulse is triggered

sodium potassium ATP-ase pump

pump that maintains the overall constant concentration levels of Na+ and K+ inside and outside of the cell

White matter is used for __ signal transmission over __ distances.

rapid; long

Phasic reception tells more about how the stimulus has __ __. Tonic reception tells more about the __ of the stimulus.

recently changed; strength

The sense organs of the ANS contain __ cells and are designed to allow those cells to collect __ info in a form that allows the __ to extract the maximum amount of info.

receptor; sensory; brain

Senses can be phasic because of the __ or __.

receptors; interpretation.

Some sense are phasic because the __ themselves are phasic while some are phasic by __, meaning the receptor is still reporting __ to the brain but the brain deems the info not __ of notice and so higher levels of consciousness __ fed that info.

receptors; interpretation; correctly; worthy; are not

activation of the sensory nerve is interpreted as coming from the receptors at the end of the neural pathway, even if AP actually started farther up the pathway

referred pain (funny bone)

hypothalamus

regulates body temperature, water balance, hunger, body weight, movements and glandular secretions of stomach and intestines, hormones that stimulate pituitary, sleep and wakefulness, emotions, memory

Conduction Velocity Depends on?

resistance to movement and membrane resistance

Chemoreceptors __________.

respond to chemical ligands that bind to a cell membrane receptor.

The sensory receptor cells of the ANS are designed to __ to a particular __.

respond; stimulus

Postsynaptic Modulation

responsiveness changed because inhibitory controls the signal and + and - cancels out so no AP

The semicircular canals detect __________ of the head:

rotational movements and rotational acceleration.

PNS Neurons

schwann, satellite ONE AXON

this structure of the ANS contains receptor cells and is designed to allow those receptor cells to collect sensory information in a form that allows the brain to extract the maximum amount of information

sense organs

Most nerves carry...processes.

sensory (afferent) and motor (efferent)

PNS

sensory and motor neurons: afferent and efferent

this structure of the ANS carriers info to the CNS

sensory neurons

synaptic cleft

separates pre- and post-synaptic membranes

graded potentials

signals that work over very short distances

Most neurons are __ receiving inputs from hundreds or thousands of synapses, some excitatory and some inhibitory; the net effect of all synapses determines the __ of the neuron.

simultaneously; firing

Divergence

single to many

synapse

site where neuron communicates with another cell

The __________ is the part of the brain that recognizes where ascending somatosensory tracts originate.

somatosensory cortex.

From dorsal to ventral, the anatomical organization of the gray matter in the spinal cord is __________.

somatosensory function is most dorsal, motor function is most ventral, and autonomic function is located between them.

neuron

structural unit of the nervous system; cells specialized for long distance transmission of electric signals

Autonomic

sympathetic, parasympathetic, enteric

connection points where neurons communicate with each other or the effectors

synapses

regions where neurons communicate with other cells

synapses

Synapses between postganglionic neurons and effector organs are different from other synapses in that __________.

there are no distinct postsynaptic sites on the effector organs and transmitter is released from several areas on the postganglionic axon.

The direction of a sound is determined by comparing the ___________ on each side of the brain.

timing of the input sound signal.

when a stimulus of constant strength continues to be felt at a constant intensity

tonic

external auditory meatus

tube that leads inward through the temporal bone

neural

tunic made of the retina

fibrous

tunic made up of the cornea and sclera

vascular

tunic made up of the iris, pupil, lens, and ciliary bodies

If the endolymph inside your anterior semicircular/superior canals were moving, you would have the sensation that your head is moving __________.

up and down (as in nodding yes).

Which of the following cranial nerves would be classified as a mixed nerve (i.e., has both efferent and afferent functions)?

vagus.

lens

very hard, clear part of eye behind pupil which focuses the light

Are action potentials always the same size?

yes

Can processes potentially regrow?

yes

Divisions of the Nervous system

(CNS) contained within the spinal Surround by meninges Brain and Spinal cord

Divisions of the Nervous system part 2

(PNS) Lies outside bony structure 12 cranial nerves and 31 pairs of spinal nerves *Cervital, Thoracic, Lumbar*

Which organs is/are controlled by both the sympathetic and parasympathetic branches of the autonomic nervous system?

- Lungs - Heart - Pancreas - Urinary bladder

What is the definition of an ionotropic receptor? A) Receptors that are generally made up of clusters of sodium or potassium ions. B) A receptor that alters ion flow when it binds with its ligand. C) A receptor that can bind ions as ligands. D) A receptor that acts through a G-protein to activate a second messenger when bound to its ligand.

A receptor that alters ion flow when it binds with its ligand.

What is a varicosity in the autonomic nervous system?

A series of swollen ends that act as synapses.

Put the following events of the action potential in the correct order, starting with depolarization: a. Na+ permeability > K+ permeability b. K+ permeability > Na+ permeability c. Vm approaches EK+ d. Vm approaches ENa+ (Vm = membrane potential; EK+ = equilibrium potential for potassium; ENa+ = equilibrium potential for sodium)

A, D, B, C.

Which cranial nerve would be damaged if a patient exhibited Bell's Palsy, a form of facial paralysis? A. CN VII (Facial) B. CN X (Vagus) C. CN V (Trigeminal) D. CN VI (Abducens)

A. CN VII (Facial)

Cranial nerves that control eye movements include the __________.

Abducens, oculomotor, and trochlear.

What is the difference between the absolute and the relative refractory periods?

Absolute Refractory Period A stimulus will NOT produce an Apot (Na+ gates are not in resting configuration) = Cell must repol to approximately -55 mV before another apot can occur. Relative Refractory Period Cell is hyperpolarized, so it is harder for a stimulus to produce an Apot (K+ gates are still open, Na+ closed - need higher stimulus to reach threshold)

Neurons in the parasympathetic pathway use which of the following neurotransmitters?

Acetylcholine.

Which of the following is a modified sympathetic ganglion?

Adrenal medulla.

If you stimulate a sensory neuron for 2 seconds with a light touch, and then again for 10 seconds with the same intensity touch, what would you expect to observe from the sensory neuron?

An increase in the duration of the action potentials delivered

Why does the action potential only travel in one direction down the axon?

Apot doesn't travel along the mem, each Apot triggers a new one down the line. The influx of Na+ make the inside of the cell positive. This affects neighboring cells and opens Na+ gates. Due to refractory period. Na+ channels are CLOSED after an APot, K+ channels are open.

Cerebrospinal fluid circulates through the central nervous system. It leaves the CNS and enters the bloodstream via which structure?

Arachnoid villus.

Schwann cells __________.

Are located in the peripheral nervous system and are a type of glial cell.

What forces cause the movement of these ions?

At rest diffusion causes this movement of ions

A stronger stimulus to a neuron results in ________. A) larger voltage changes in the graded potentials, but no changes in action potentials B) larger voltage changes in graded potentials and greater frequency of action potentials produced in response C) greater frequency of graded potentials and larger voltage changes in the action potentials produced in response D) larger voltage changes in both graded and action potentials

B) larger voltage changes in graded potentials and greater frequency of action potentials produced in response

Which of the following are components of the central nervous sytsem?

Brain, spinal cord.

The reticular formation is a network of neurons found along the brainstem. Many of the functions of the reticular formation are widespread as a result. Which of the following would occur if you were to disrupt the functions of the reticular formation? Choose the best answer. A. A person would have exaggerated behavioral drives. B. A person would no longer be able to release melatonin. C. A person would have a difficult time waking due to an inability to arouse the brain. D. A person would not be able to breathe due to an inability to control respiration

C. A person would have a difficult time waking due to an inability to arouse the brain

What are the functions of the axon hillock and the axon terminal?

Carries information as an action potential - a self-regenerating electrical signal wave that propagates from the point of initiation at the cell body (axon hillock) to the axon terminal where it releases chemicals

The ventral horn of the spinal cord contains __________.

Cell bodies of efferent neurons.

The brain region that is identifiable by its folds and grooves is the?

Cerebellum and Cerebrum.

Muscarine, a chemical produced by certain mushrooms, binds to muscarinic receptors mimicking the effect of acetylcholine. How do you think administering this chemical would change body function? The drug would ______

Change the functionality of the heart, the functionality of the smooth muscle within the digestive system and change the functionality of certain exocrine and endocrine glands.

Cerbrospinal fluid is produced by the?

Choroid plexus.

What is responsible for selectively transporting substances into the ventricles from the bloodstream?

Choroid plexus.

When a cell's membrane potential becomes less negative or even positive, the cell is said to be ____________.

Depolarized.

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.

Sometimes the effects of sympathetic stimulation can be contradictory in the same types of tissue. What mechanism explains these opposite effects?

Different receptors for the same neurotransmitter.

Refractory periods contribute to which of the following properties of action potentials?

Directionality, all or none, and coding of stimulus strength by frequency

Cell bodies of sensory neurons are located in?

Dorsal root ganglia.

The cell body (soma) of a somatic sensory neuron is located in the ____________.

Dorsal root ganglion.

If a signal from a sending neuron makes the receiving neuron more negative inside, A) the receiving neuron immediately generates an action potential. B) the sending neuron becomes more negative inside. C) the receiving neuron is more likely to generate an action potential. D) the sending neuron becomes more positive inside. E) the receiving neuron is less likely to generate an action potential.

E) the receiving neuron is less likely to generate an action potential.

When calcium ions enter the synaptic terminal, A) the inside of the receiving neuron becomes more negative. B) neurotransmitter molecules are quickly removed from the synaptic cleft. C) they cause an action potential in the sending neuron. D) the inside of the receiving neuron becomes more positive. E) they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

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

What factors increase the velocity of propagation down an axon? Why?

Fast = postural reflexes = 1000 m/sec Slow = serves GI tract, B V Fiber Diameter Impulse traveling down axon likes water going down leaky hose. Larger diameter = faster conduction. Myelin (300 layers of membrane, carries imp information Increases apot conduction velocity, helps prevent flow of ions through membrane saltitory conduction = AP hops from node to node (voltage gated Na channels in nodes of ranvier)

What causes the hyperpolarization? What channels are open/closed? What ions are moving in or out of the cell?

Fast Na channel = some are repolarizing, some are at rest but nothing is going thru Slow Na channel = closed Slow K channel = still open starting to close because K channels are still opened K continues to move out so the inside becomes even more negative than at rest

Which brain lobe contains the main areas controlling skeletal muscle movement?

Frontal.

What is the function of the dendrites?

Function = receive information - main receptive surface of neuron - high surface area - connect to hundreds to thousands of connections

Nerve and muscle cells are classified as excitable tissues because they __________.

Generate electrical signals and propagate electrical signals.

Which of the following conditions occurs within photoreceptors in the dark?

High cGMP levels.

Most neurons contain a large number of mitochondria. Which characteristic of neurons does this reflect?

High level of aerobic metabolism.

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.

How will a neuron convey information about a sensory signal that has increased in intensity?

Increase the frequency of the action potentials delivered.

Which of the following is likely to occur when someone stands up quickly?

Increased release of norepinephrine and increased activity at adrenergic receptors.

Efferent

Info from the CNS Somatic (skeletal) Autonomic (smooth, cardiac)

Afferent

Information to the CNS

The dorsal columns consist of ascending tracts. This means that they convey _____________.

Information to the brain.

IPSP

Inhibitory Postsynaptic Potential -adds - charges. hyperpolarizes, cancels out ESPS

Where do most action potentials originate?

Initial segment.

During an action potential, activation of voltage-gated sodium and potassium channels occurs at different rates. What is the difference on ion flow across an axon membrane?

Initially, Na+ flows into the cell followed by K+ flowing out of the cell.

Nerve cells in the central nervous system are primarily a)sensory neurons. b)glia. c)interneurons. d)motor neurons.

Interneurons.

Nerve cells in the central nervous system are primarily:

Interneurons.

Nerve cells in the central nervous system are primarily?

Interneurons.

The neurons of the central nervous system are also known as?

Interneurons.

Why does rubbing your skin after receiving a painful stimulus often result in a feeling as though the pain has been lessened?

It is hypothesized that inhibitory interneurons are activated by the collaterals of an activated neuron associated with a mechanoreceptor from the skin. The gate-control theory of pain modulation may account for this phenomenon.

Why is the parasympathetic nervous system also called the cranio-sacral division?

Its nerves arise in the head and sacrum.

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?

Leak channels.

What is an appropriate classification for the ACh receptor found in the neuromuscular junction?

Ligand-gated, nonspecific, cation channel

The part of the brain known as the center of emotion is the ________.

Limbic system.

The part of the brain known as the center of emotion is the?

Limbic system.

__________ carry information about movement, location, and depth perception; __________ transmit signals that pertain to color, form, and texture of objects in the visual field.

M cells; P cells.

What is a disease in which myelin is lost?

MS - autoimmune - glial cells destroy cells that make myelin

brain and spinal chord

Makes up the central nervous system

What part of the brain controls the involuntary functions of the body? (breathing, vomiting, heart rate)

Medulla oblongata.

Which area of the brain controls basic functions as breathing, swallowing, and vomiting?

Medulla oblongata.

What part of the brain will play a role in eye movement?

Midbrain.

Which of the following increases acuity?

More receptive fields, overlapping receptive fields, and lateral inhibition.

To which ion is the membrane most permeable?

Most permeable to K+ because there are more K channels

Fast axonal transport refers to __________ down the length of the axon away from the cell body (soma).

Movement of proteins packaged in vesicles.

Which of the following is not a function of glial cells?

Movement.

What type of drug would decrease heart rate?

Muscarinic agonist.

In which type of axon will velocity of action potential conduction be the fastest?

Myelinated axons with the largest diameter.

Gutamate is a _______ ; its receptor is _______

NT ; AAMPA & NMDA

Chemical Synapse

NT released cell to cell, excitatory & inhibitory, one way communicationg

If the stimulus reaching a receptor is intense, the receptor will release a lot of __, making the GP __, causing the neuron to fire a burst of __.

NT; long; AP

The positive feedback loop during the depolarization phase of the action potential is "turned off" during repolarization because __________.

Na+ channels inactivate and K+ channels open.

What is an action potential?

Nerve and muscle cells are excitable cells - they can use the membrane potential to fire (change in membrane potential = communication signals. Produced if change in membrane permeability or change in ion concentration). Action potentials result from a transient change in membrane ion permeability (concentration gradient doesn't change). For a brief period of time, the INSIDE of the nerve cell becomes POSITIVELY charged compared to the outside. Action potential actually due to the movement of just a few ions. (1/100,000). So the concentration gradient still exists. You can have repeated apots without depleting the concentration gradient. Nonetheless, the pump restores the gradient so it won't run down.

Nervous system cells that are specialized to use action potentials to transmit information are called __________.

Neurons.

A molecule that carries information across a synaptic cleft is a neurotransmitter. synaptic cleft. receiving neuron. synapse. sending neuron.

Neurotransmitter.

A molecule that carries information across a synaptic cleft is a:

Neurotransmitter.

A molecule that carries information across a synaptic cleft is a?

Neurotransmitter.

The chemical messengers released into synapses are called __________.

Neurotransmitters.

The two main types of acetylcholine receptor are known as?

Nicotinic and Muscarinic.

Which neural term is synonymous with rough endoplasmic reticulum?

Nissl substance.

What characterizes repolarization, the second phase of the action potential?

Once the membrane depolarizes to a peak value of +30mV, it repolarizes to it's negative resting value of -70mV.

What initiates exocytosis of synaptic vesicle contents in an axon terminal?

Opening of voltage-gated Ca2 channels.

Are ganglia in the CNS or PNS?

PNS

Are nerves in the CNS or PNS?

PNS

In which system are processes more likely to regrow?

PNS

non brain and cord neural material

PNS (peripheral)

Afferent signals from nociceptors produce what type of sensation?

Pain and itching.

the support cells that myelinate in the PNS

Schwann cells

What types of cells make myelin in the PNS and CNS?

Schwann cells - PNS - wrap around the axon like jelly roll Oligodendrocytes - CNS - each can myelinate up to 60

The phenomenon of referred pain is due to the fact that __________.

Second-order neurons receive information from both somatic and visceral afferents and the brain interprets new sensory information based on past sensory experience.

Which of the following is true about stimulus coding?

Stimulus intensity can be coded by frequency of action potentials and stimulus intensity can be coded by the amplitude of the receptor potential.

-40, -90

THE MAGNITUDE OF THE RESTING MEMBRANE POTENTIAL in neurons VARIES BETWEEN ____ to ____ mV

Application of the poison tetrodotoxin (TTX) to a neuron blocks voltage-gated Na+ channels. What effect will this have on an action potential in the neuron?

TTX will diminish or abolish the depolarization phase of the action potential.

The primary auditory cortex is located in the __________ lobe.

Temporal.

The tertiary neuron in somatosensory pathways delivers information between which two structures?

Thalamus to postcentral gyrus.

Composed of many small nuclei, an area that integrates as well as relays sensory information that passes through it.

Thalamus.

In neurons that generate many action potentials, why don't the ion gradients across the neuron's cell membrane dissipate?

The Na+/K+ ATPase helps reestablish the gradients by actively transporting these ions back across the neuronal membrane and even though the membrane potential can change dramatically, very few ions actually move across the neuronal membrane during each action potential.

What best describes the concept of permeability?

The ability of a molecule to cross the cell membrane.

What makes the brain more complex than a simple, reflex pathway?

The ability to generate information in the absence of external input.

In sodium channels at the resting membrane potential, __________.

The activation gate is closed and the inactivation gate is open.

From what does the blood-brain barrier result? Which of the following best describes the role of the blood-brain barrier?

The blood-brain barrier is formed by tight junctions between capillary endothelial cells thus preventing the movement of solutes between cells.

Why is an action potential conducted in only one direction, from an axon hillock to an axon terminal?

The membrane channels upstream are refractory and cannot open.

What event triggers the generation of an action potential?

The membrane potential must depolarize from the resting voltage of -70mV to a threshold of -55mV.

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.

In a graded potential, what is the effect of cytoplasmic resistance and current leak?

The strength of the signal inside the cell decreases over distance.

The effects of the sympathetic nervous system are divergent, meaning that a single stimulus can have an effect on a large number of targets. In other words, when the SNS is activated, all of the organs it innervates are stimulated. This does not occur in the parasympathetic system. Why?

The sympathetic ganglia spreads the stimulus to all postganglionic sympathetic neurons.

Whether or not a neuron produces an action potential at a given moment depends on?

The total potential change reaching threshold voltage at the trigger zone.

The occipital lobe of the cerebrum plays an important role in ________.

Vision.

Be familiar with the structure and characteristics K+ voltage gated channels. What is the "fast" channel? The "slow" channel?

Voltage gated K+ channels = Slow gate: closed at rest (open up to let K out) Depolarization = opens slow gate (slowly!)

Be familiar with the structure and characteristics Na+ voltage gated channels. What is the "fast" channel? The "slow" channel?

Voltage gated Na+ channels = Na+ and water can pass through, Fast gates = closed at rest (voltage sensitive, opens to allow Na to move into a cell) Slow gates = open at rest TIME SESITIVE (causes to stop allowing Na to cell Depolarization = opens fast gates, closes slow gates (slowly!)

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

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

What opens first in response to a threshold stimulus?

Voltage-gated Na+ channels.

tracts, pathways

_____ or _____ are groups of afferent and efferent nerve fibers (in the CNS)

The major neurotransmitters/neurohormones of the autonomic nervous system are __________.

acetylcholine, epinephrine, and norepinephrine.

parasympathetic

activates body for rest or digestion (division of autonomic)

sympathetic

activates the body for fight or flight response; when stressed, excited, or accelerated (division of autonomic)

each kind of sensory receptor cell is designed to respond very sensitively to one particular type of stimulus, called its...

adequate stimulus

What is the path of sensory receptor cells (that are not neurons) leading to an AP reaching the CNS?

adequate stimulus causes receptor to form a GP; GP causes receptor to release an NT; a neuron synapsed to the receptor cell receives the NT and develops own GP; when the neuron reaches threshold it fires an AP towards the CNS

Heuristics: APs coming from a neuron are always perceived as the __ __ of the __ at the __ of the neural pathway.

adequate stimulus; receptor; end

Are sensory processes afferent or efferent?

afferent

What cell releases the neurotransmitters to diffuse across the synaptic cleft?

afferent

sending, in terms of synapses

afferent

dendrites

afferent fibers--bring signal toward cell body; receive information; increase surface area

sensory neurons

afferent neurons that carry nerve impulses to brain; sense environment

tympanic cavity

air-filled space in temporal bone that contains auditory ossicles

In the autonomic nervous system, acetylcholine is released by __________.

all preganglionic sympathetic neurons, all preganglionic parasympathetic neurons, and all postganglionic sympathetic neurons.

cones

allow vision when there is sufficient light to permit close detailed vision; enable one to see detail; are responsible for colored vision

malleus

attached to eardrum; vibrates in unison (aka hammer)

Axons carry info __ the cell body, __ synapses with other cells.

away; towards

What are the types of processes?

axons; dendrites

Activation of __________ adrenergic receptors raises the concentration of cAMP in effector cells.

beta 1 and beta 2.

houses the nucleus and most organelles

cell body

soma

cell body of neuron

spinal chord

column of nerve tissue that starts in the medulla oblongata and runs down vertebral column

permeability

communication by neurons is based on changes in the membrane's _________ to ions

electrical potential

condition in which sperated charges of opposite polarity have the POTENTIAL to do work if they are allowed to come together (measured in voltage)

tympanic membrane

cone-shaped membrane attached to the malleus; reproduces sound waves (aka eardrum)

As you focus on the words in this question, you are primarily using your __________.

cones and fovea.

pons

connects medulla oblongata to midbrain; transmits impulses from cerebrum to cerebellum

eustachian tube

connects middle ear to throat; conducts air between tympanic cavity and the outside of body; helps maintain equal air pressure on both sides of eardrum (aka auditory tube)

corpus callosum

connects the two hemispheres of cerebrum

cochlea

contains receptor cells called hair cells; vibrations in fluid picked up by hair cells

How are dendrites different from axons?

dendrites receive in the information and axons send it out, also axon hillock (voltage gated channels) and dendrites (chemical gated channels)

axon terminals

distal ends of axons that release neurotransmitters

sympathetic and parasympathetic

divisions of autonomic

somatic and autonomic

divisions of efferent

this structure of the ANS contains the cell bodies of some sensory neurons and allow for some sorting of info

ganglia

Nerves and ganglia are often associated. __ house the cell bodies whose __ make up the __.

ganglia; processes; nerves

Electrical Synapse

gap junctions connect two cytoplasms, excitatory, two way communication

meninges

general name for the three layers covering the brain

Are ganglia white or gray matter?

gray

The brain stem ________.

has nuclei located throughout it that are associated with reticular formation.

rules the brain uses to interpret the info so that you can perceive

heuristics

resistance

hindrance to movement of electrical charge (current)

What is an example of phasic perception?

hot tub (feels warm at first then not as hot)

When will the efferent (post-synaptic) cell experience its own AP?

if it is excitable and threshold membrane potential is reached

increase mylenation

increase membrane resistance, decrease current leak

The purpose of the afferent nervous system is to collect information about the __ and __ world and carry it to the __.

internal; external; brain

autonomic

involuntary; regulates smooth muscle, cardiac muscle, and glandular secretions (division of efferent)

The somatic senses __________.

involve receptors that consist of a neuron with naked free nerve endings or ones with nerve endings encased in connective tissue capsules.

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.

astigmatism

irregularity in the curve of the cornea or lens

Cerebrospinal fluid __________.

is reabsorbed by the venous system and is the interstitial fluid of the CNS.

cataracts

lens becomes cloudy

cerebrum

made up of frontal, parietal, temporal, and occipital lobes

peripheral nervous system

made up of peripheral nerves

external ear

made up of pinna, external auditory meatus, and the eardrum

inner ear

made up of semicircular canals, the chochlea, & the auditory (eustachian) tube

The bones of the middle ear include all of the following except the __________.

mastoid.

conductors

material with very little resistance-- allow rapid flow of current

insulators

materials with high resistance

Receptors that are sensitive to changes in pressure, cell stretch, vibrations, accelerations, and sounds are called __________.

mechanoreceptors.

Define "threshold." What voltage (in mV) is threshold? What does "threshold" mean?

membrane potential at which outward current carried by K+ = inward Na+ current. If more Na+ in, opens Na+ VG channels Need depolarization of 15 - 20 mV, brings nerve cell to -55 mV. When reaches threshold, the depolarization becomes self-generating, Na+ channels open themselves It is important to note that the big spike (depolarization) from -55 to +35 mV is not due to the initial stimulation, but due to the opening of Na+ channels in the membrane.

Most often, __ synaptic events are needed to raise the cell to threshold to fire an AP.

multiple

APs travel normally across __ but skip __ areas and restart in the next node as the charge has been transferred __the myelinated region. This hopping is called __ conduction, it's __.

nodes of Ranvier; myelinated; underneath; saltatory; rapid

lumps of neuron cell bodies in the CNS; gray matter

nuclei

What are found in the CNS (ganglia, nerves, nuclei, tracts)?

nuclei; tracts

The cortex of the temporal lobe contains ______________.

olfactory cortex, primary auditory cortex, auditory association cortex, Wernicke's area.

the support cells that myelinate in the CNS

oligodendrocytes

CNS Neurons

oligondendrocytes, astrocytes, microglia, ependymal MANY AXONS

Each synapse will be designed to use __ __ NT.

only one

cornea

outside front of the eye; important in focusing light onto the retina; can become damaged by foreign objects, chemicals, or trauma

Why do you feel a papercut before it hurts?

pain and touch are controlled by different nerves

incus

passes vibration from hammer to stirrup (aka anvil)

stapes

passes vibration onto fluid within inner ear (aka stirrup)

All __ arises in the __.

perception; brain

rods

permit vision when there is dim light; form outlines or silhouettes of objects and are concerned with twilight vision

A stimulus is applied to the back of your hand, which results in the activation of two sensory neurons. The stimulus is applied a second time but this time it activates five sensory receptors because this new stimulus is stronger. The recruitment of sensory neurons is known as __________.

population coding.

resting membrane potential

resting condition of cells at which the inside of the cell is negative with respect to the outside of the cell

The light-absorbing portion of the photoreceptor visual pigments is a derivative of the compound __________.

retinal.

neuronal signals

rods and cones change light waves into ______ ______.

afferent neurons

sensory neurons--carry signal from PNS to CNS; have sensory receptors at peripheral ends

Because of brain lateralization, the left brain is generally associated with __________.

sensory perception on the right side of the body.

this structure of the ANS is designed tor respond to a particular stimulus

sensory receptor cells

What are the structures of the afferent nervous system?

sensory receptor cells; sense organs; sensory neurons; ganglia

myelin sheath

sheath around an axon; increases impulse propagation rate along axon

Sometimes a __ receptor event in a single neuron is sufficient to cause an AP in the afferent cell, such as __ neurons innervating __ muscles.

single; motor; skeletal

What are the nodes of Ranvier?

sites of no myelin, lots of Na+ channels, saltatory conduction

dendrite

slender, sensitive process on a nerve extending from the cell body

What is the synapse?

space between two neurons, between axons and dendrites

neuroglia

specialized cells that provide support, nutrition and insulation for neurons

microglia

specialized glial cells that engulf foreign materials and bacteria (like phagocytes)

astrocytes

specialized glial cells that pass blood between neurons and capillaries and remove waste remove K+ ions and neurotransmitters around synapse help form blood-brain barrier

ependymal cells

specialized glial cells that secrete cerebrospinal fluid

insulating cells

specialized glial cells that wrap some fibers in a thick myelin sheath; sun fibers are said to be myelinated fibers (white matter in CNS); those without are unmyelinated (gray matter in the CNS)

Myelinated processes are insulated and this __ and __ the transfer of charge along the axon, even though they can't conduct APs.

speeds; extends

CNS areas that are involved in the control of autonomic functions include the __________.

spinal cord, hypothalamus, and pons.

What is an example of a tonic perception?

staring at an immobile object and continuing to see it clearly

What could possibly provide a replacement for neurons?

stem cells

Reducing the intensity of a painful stimulus may involve __________.

stimulation of Αβ fibers.

Heuristics problem: a __ __-__ stimulus that impacts the receptor __ activates it __, leading to a __ perception of the adequate stimulus.

strong; non-adequate; accidentally; a little; weak (i.e., seeing stars of you take trauma to the eyes)

What is the stimulus for thermoreceptors? General design? Examples?

temperature; temperature-gated ion channels; heat and cold receptors, in skin and internally

In the inner ear __________.

the louder the sound, the more potassium channels open in the hair cells associated with the pitch of the sound and the pitch of a sound is coded by the location of the hair cells which response to a sound wave of a particular frequency.

Similarities between autonomic neuroeffector synapses and the neuromuscular junction include __________.

the presence of enzymes such as acetylcholinesterase or monoamine oxidase and the requirement for calcium to produce transmitter release

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.

-70 mV

the resting membrane potential for a typical neuron using the GHK equation

In the visual pathway __________.

the right visual field is topographically mapped onto the left visual cortex.

fibrous, vascular, neural

the three layers (tunics) of the eye

in this reception the system always accurately reports the actual intensity of the stimulus, no matter what has come before

tonic

Sensory reception may be __ or __.

tonic; phasic

Sensory receptors that are slowly adapting that respond for the duration of the stimulus are __________ receptors while those that rapidly adapt to a constant stimulus and then turn off are ___________ receptors.

tonic; phasic.

Dendrites carry info __ the cell body.

towards

bundles of processes running together in the CNS; white matter

tracts

The conversion of the energy in a stimulus into a change in membrane potential in sensory cells is called __________.

transduction.

The conversion of stimulus energy into information that can be processed by the nervous system is called __________. Each sensory receptor has a(n) __________, a particular form of energy to which it is most responsive. The minimum stimulus level required to activate a receptor is called the __________.

transduction; adequate stimulus; threshold.

membrane potential

transient changes in the _________ from its resting state produce electrical signals

auditory ossicles

transmit vibrations between eardrum and inner ear

What is the stimulus for nociceptors? General design? Examples?

varies but all interpreted as painful; not really receptor type, name given to any receptor designed to produce pain; chemoreceptors (inflammation pain) and mechanoreceptors (trauma to tissues pain)

Graded Potentials

vary in size, doesn't have to be all or none: stimulus opens gated channel, de or hyper, size related to stimulus strength

somatic

voluntary; controls skeletal muscle contractions (division of efferent)

arachnoid mater

well vascularized middle layer covering the brain; main site of blood brain barrier

The blind spot of the eye is __________.

where the optic nerve exits the eye.

The brain knows which neuron brought in the APs, specifically from __ in the body that neuron __ info and from what kind of __ the neuron __ info.

where; collects; receptor; collects

What information does the brain have for receptor activation?

which neuron brought in the APs; how many APs arrive per unit time; memories, expectations and stored info

Are nerves white or gray matter?

white

Are tracts gray or white matter?

white

What is faster, white or gray matter transmission?

white

myelinated, rapid, long distances, no AP; type of matter

white