Anatomy Exam 3

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how are neurons with several processes branching off the cell body, such as motor neurons and interneurons, structurally classified?

multipolar

Saltatory conduction is made possible by ________.

myelin sheath

The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________.

negative charge and contains less sodium than oustside the cell

afferent or sensory neurons

neurons that send messages from the sense organs to the brain

In the central nervous system myelin is formed by

oligodendrocytes

Schwann cells are functionally similar to ________.

oligodendrocytes

A shallow groove or depressions between a gyrus on the surface of the cortex is called a ________.

sulcus

subdivisions of autonomic nervous system

sympathetic and parasympathetic

Which branch of the autonomic nervous system (ANS) mobilizes the body during extreme situations, such as rage or fear?

sympathetic division

Neurons either conduct action potentials along the length of their axons, or they remain at rest. This statement best describes ____.

the all-or-none response

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart). Its sympathetic division arouses; its parasympathetic division calms.

During the relative refractory period of an action potential, a larger than normal stimulus is needed to cause another action potential. This is due to the fact that ________.

the voltage gated potassium ion channels remain open long enough to hyperpolarize the axon membrane

function of myelin sheath

to protect the neuron, provide insulation, and increase the speed of impulse transmission

Function of neurotransmitters

to transmit nerve impulses across synapses

Axon diameter and degree of myelination determine nerve impulse conduction velocity T or F

true

Cerebrospinal fluid circulates within the ventricles of the brain and in the subarachnoid space. T or F

true

During depolarization, the inside of the neuron's membrane becomes less negative. T or F

true

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

true

Reflexes are rapid, automatic responses to stimuli that will produce the same effect every time. T or F

true

The adult spinal cord ends between the level L1 and L2 of the vertebral column. T or F

true

The main neurotransmitter of the sympathetic nervous system is Epinephrine (Adrenaline).

true

The sciatic nerve is the largest nerve of the body.

true

Which area of the spinal cord contains cell bodies of motor neurons leaving the spinal cord?

ventral horn

The interconnected fluid-filled cavities in the brain are called

ventricles

immediately after an action potential has peaked, which of the following channels will open?

voltage gated potassium channels

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

innervation of skeletal muscle

Which of the following correctly describes a graded potential?

it can have amplitudes of various sizes

Which fissure separates the cerebral hemispheres?

longitudinal fissure

Vital centers for the control of heart rate, respiration, and blood pressure are located in the ________.

medulla oblongata

the brain and the spinal cord are protected and cushioned by three connective tissue membranes that are collectively called

meninges

Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection?

microglia

Describe the ANS

motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

Mr. Warren has spinal cord damage that prevents nerve impulses from being carried from the CNS to muscles or glands. What specific type of neuron has been damaged?

motor neuron

function of synaptic vesicles

store neurotransmitters

Within the meninges, cerebrospinal fluid occupies the

subarachnoid space.

The outermost layer of the meninges is the ________ mater.

dura

Control of temperature, endocrine activity, and thirst are functions associated with the ________.

hypothalamus

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

How many pairs of cranial nerves branch from the surface of the brain?

12

Which of the following is correct sequence of events that correlates to the sequence of events of a nerve impulse? 1. the membrane becomes depolarized 2. sodium channels open and sodium ions diffuse inward 3. the membrane becomes repolarized 4. potassium channels open and potassium ions diffuse outward

2,1,4,3

how many pairs of spinal nerves emerge from the spinal cord?

31

Which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle? A) acetylcholine B) cholinesterase C) gamma aminobutyric acid D) norepinephrine

A) acetylcholine

When a neurotransmitter like GABA is acting in an inhibitory manner which of the following is likely a result of the GABA acting on the post synaptic cell? A) hyperpolarization of the postsynaptic cell membrane B) depolarization of the postsynaptic cell membrane C) influx of positively charged ions into the postsynaptic cell D) opening of chemically gated sodium channels

A) hyperpolarization of the postsynaptic cell membrane

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

B) provide the defense for the CNS

Sally has a brain injury; she knows what she wants to say but can't vocalize the words. The part of her brain that deals with the ability to speak is the:

Broca's area

Select the correct statement regarding chemical synapses. A) Cells with gap junctions use chemical synapses. B) Neurotransmitter receptors are located on the axons terminals of cells. C) The synaptic cleft uses the action potential to transmit a chemical signal to the post synaptic cell. D) The release of neurotransmitter molecules gives cells the property of being electrically coupled.

C) The synaptic cleft uses the action potential to transmit a chemical signal to the post synaptic cell.

When a neurotransmitter like acetylcholine is acting in an excitatory manner which of the following is likely a result of the acetylcholine acting on the post synaptic cell?

Chemically gated sodium channels will open.

Which describes the ion concentrations inside and outside of a neuron? A) Sodium and potassium ions are both at higher concentration on the outside of the cell. B) The concentrations of sodium and potassium ions are both equal inside and outside of the cell. C) Sodium and potassium ions are both at higher concentration on the inside of the cell. D) The sodium ion concentration is higher on the outside of the cell and potassium ion concentration is higher on the inside of the cell. E) The sodium ion concentration is higher on the inside of the cell and potassium ion concentration is higher on the outside of the cell.

D) The sodium ion concentration is higher on the outside of the cell and potassium ion concentration is higher on the inside of the cell.

Which of the following is not characteristic of neurons? A) They have extreme longevity. B) They have an exceptionally high metabolic rate. C) They conduct impulses. D) They are mitotic.

D) They are mitotic.

Loss of function in the enzyme acetylcholinesterase would result in which of the following? A) stimulation of the production of acetylcholine B) amplify or enhance the effect of ACh C) inability to release acetylcholine D) inability to destroy and remove acetylcholine from the synaptic cleft

D) inability to destroy and remove acetylcholine from the synaptic cleft

Which of the following is NOT a type of neuroglia? A) Ependymal cell B) Microglial cell C) Oligodendrocyte D) Neuron E) Astrocyte

D) neuron

Which of the following lists parts of a reflex arc in the correct sequence? A) Effector, receptor, sensory neuron, motor neuron B) Receptor, motor neuron, sensory neuron, effector C) Effector, sensory neuron, receptor, motor neuron D) Receptor, effector, sensory neuron, motor neuron E) Receptor, sensory neuron, motor neuron, effector

E) Receptor, sensory neuron, motor neuron, effector

Interneurons are specialized to carry impulses from peripheral receptors into the brain or spinal cord. T or F

False

Nodes of Ranvier connect adjacent neurons. T or F

False

The arbor vitae is part of the cerebrum. T or F

False

efferent or motor neurons

Nerve cell that carries messages away from the central nervous system toward the muscles and glands

what is the name of cranial nerve III

Oculomotor

What cells form the myelin sheaths around nerve fibers in the PNS?

Schwann cells

function of synaptic terminals

Store and release neurotransmitters Helps regulate exocytosis of neurotransmitters Synapses w/ bipolar cells in photoreceptors

The depolarization phase of an action potential is punctuated by the closing of inactivation gates in the voltage gated sodium ion channels. what is not a consequence of the closing of inactivating gates

This allows for the efflux (diffusion out) of potassium ions, resulting in the repolarization of the cell.

function of axon hillock

To help determine if the action potential is strong enough to send

A synapse is the functional connection between two neurons. T or F

True

Astrocytes provide structural support in the nervous system. T or F

True

Cell bodies of motor neurons are located in the anterior horns of the spinal cord. T or F

True

If a post synaptic neuron is stimulated to threshold by spatial summation this implies that ________.

a presynaptic neuron is sending frequent EPSP

The period after an initial stimulus when a neuron is not sensitive to another stimulus is the ________. (ie, no other action potential may be produced)

absolute refractory period

which of the following is an excitatory neurotransmitter secreted by motor neurons innervating skeletal muscle?

acetylcholine

Function of Nodes of Ranvier

allow an action potential to propagate quickly down an axon

Bacteria in the blood can be prevented entry to the fluids surrounding the brain. Which cells are most responsible for preventing bacteria from entering the fluids of the brain?

astrocytes

the concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. what cell is responsible for this?

astrocytes

Control of temperature, endocrine activity, metabolism, and thirst are functions associated with the ________.

hypothalamus

function of cerebrospinal fluid

bathes the brain, acts as a shock absorber, transports nutrients, chemical messengers, and waste products.

Major Organs of the Central Nervous System

brain and spinal cord

The term central nervous system refers to the

brain and spinal cord

The term central nervous system refers to the ________.

brain and spinal cord

The midbrain, pons, and medulla oblongata are housed in the

brain stem

In the case of a subdural hematoma (blood accumulating beneath the dura) resulting from a blow to the head, blood accumulates between the

dura mater and arachnoid mater.

function of axon

carries nerve impulses away from the cell body

function of motor neurons

carry impulses from the CNS to effectors

Ganglia are collections of ________.

cell bodies

What are the two main divisions of the nervous system?

central and peripheral

The arbor vitae refers to ________.

cerebellar white matter

The brain area responsible for maintaining balance and coordinates movements is the _________..

cerebellum

The part of the brain that coordinates voluntary muscle movements is the

cerebellum

function of interneurons

connect sensory and motor neurons

function of cell body (soma)

contains the nucleus of the neuron

function of sensory neurons

deliver information to CNS

The cellular processes of neurons that provide receptive surfaces for input from other neurons are

dendrites

The ________ is a connective tissue wrapping around a single neuron fibers.

endoneurium

These cells in the CNS have cilia that move in order to circulate cerebrospinal fluid ________.

ependymal cells

What type of cells line the ventricles of the brain?

ependymal cells

All cranial nerves are mixed nerves.

false

Meningitis is the most accurate term for inflammation of neurons. T or F

false

The wrinkles on the cerebellum are called a gyrus.

false

Bipolar neurons are commonly ________.

found in the retina of the eye

Which ventricle is continuous with the central canal of the spinal cord?

fourth

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

ganglia

Ridges of tissue on the surface of the cerebral hemispheres are called ________.

gyri

Nervous control

hormonal control

Endocrine control

hormones; slow & long lasting

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

hyperpolarization

when a neurotransmitter like GABA is acting in an inhibitory manner what is a likely result of the GABA acting on the post synaptic cell?

hyperpolarization of the postsynaptic cell membrane

What division of the autonomic nervous system is often called the "rest-and-digest" division?

parasympathetic

Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

parasympathetic division

during repolarization, what ions are pumped out of the cell?

potassium

During an action potential, repolarization occurs as a result of

potassium ions diffusing to the outside of the cell membrane.

function of synaptic cleft

prevents nerve impulses from directly passing from one neuron to the next

function of nissl bodies

protein synthesis

function of dendrites

receive incoming signals from other neurons

what is the correct sequence in a typical reflex arc?

receptor, sensory neuron, integration center, motor neuron, effecter

function of neurilemma

regeneration of damaged axons

A special group of neurons in the gray matter of the brain stem that plays a role in consciousness and the awake/sleep cycle is the

reticular activating system (RAS)

A special group of neurons in the gray matter of the brain stem that plays a role in consciousness and the awake/sleep cycles is the ________.

reticular activating system (RAS)

nerve impulse transmission occurring along myelinated neurons are called

saltatory conduction

Cranial nerve II, the optic nerve sends nerve impulses to the brain carrying information about the things we see. These nerve fibers most likely belong to which division of the nervous system?

sensory (afferent) division

Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

sensory (afferent) division

During an action potential, depolarization occurs as a result of

sodium ions diffusing to the inside of the cell membrane

Nerve impulses leading to the skeletal muscle carry information to direct movement. The nerve fibers sending these signals will most likely belong to which division of the nervous system?

somatic nervous system

subdivisions of efferent division

somatic nervous system and autonomic nervous system

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

Masses of myelinated nerve fibers appear

white

Myelinated fibers (tracts) form ________ matter while unmyelinated fibers form ________ matter.

white; gray


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