Nervous System (Pearson MyLab & Mastering A&P)

Question 1

Which of the following is the correct simple spinal reflex arc?

(One answer)

• effector, afferent neuron, integration center, efferent neuron, receptor
• effector, efferent neuron, integration center, afferent neuron, receptor
• receptor, afferent neuron, integration center, efferent neuron, effector
• receptor, efferent neuron, integration center, afferent neuron, effector

Answer 1

receptor, afferent neuron, integration center, efferent neuron, effector

Question 2

At age 79, Mrs. X is diagnosed with a disorder that severely impairs her logical judgment. Medical imaging techniques show that this has been most likely caused by brain damage in a _______?

(One answer)

• parietal lobe
• frontal lobe
• temporal lobe
• premotor cortex

Answer 2

frontal lobe

Question 3

Which of the neuroglial cell types shown are found in the peripheral nervous system (PNS)?

(One Answer)

• A
• B
• C
• E

Answer 3

E

Question 4

Which of the following is NOT a correctly matched pair?

(One answer)

• gray matter: myelinated axons
• superficial in the brain: gray matter
• spinal cord: inner gray matter
• gray matter: location of brain nuclei

Answer 4

gray matter: myelinated axons

Question 5

Which of these activities is most likely driven by parasympathetic innervation?

(One answer)

• sweating and dilating pupils
• vigorous physical activity
• resting and digesting
• fight-or-flight responses

Answer 5

resting and digesting

Question 6

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

(One answer)

• innervation of glands
• innervation of cardiac muscle
• innervation of smooth muscle of the digestive tract
• innervation of skeletal muscle

Answer 6

innervation of skeletal muscle

Question 7

Which motor area both has a homunculus and has descending projection fibers?

(One answer)

• frontal eye fields
• Broca’s area
• premotor cortex
• primary motor cortex

Answer 7

primary motor cortex

Question 8

Which of the following is NOT a function of the CSF?

(One answer)

• protection from blows
• reduction of brain weight
• initiation of some nerve impulses
• nourishment of the brain

Answer 8

initiation of some nerve impulses

Question 9

A patient is suffering from the inability to distinguish various types of odors. This patient may have damage to which of the following?

(One answer)

• hypoglossal nerve (XII)
• facial nerve (VIII)
• olfactory nerve (1)
• vagus nerve (X)

Answer 9

olfactory nerve (1)

Question 10

The “fight or flight” division of the autonomic nervous system is the ______?

(One answer)

• sympathetic division
• somatic division
• peripheral division
• parasympathetic division

Answer 10

sympathetic division

Question 11

A doctor asks her patient to follow the motion of her finger as she moves it up and down, left and right. Which of the following cranial nerves is NOT being tested?

(One answer)

• the vestibulocochlear nerve (VIll)
• the oculomotor nerve (Ill)
• the trochlear nerve (IV)
• the abducens (VI)

Answer 11

the vestibulocochlear nerve (VIll)

Question 12

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

(one answer)

• midbrain
• cerebrum
• medulla oblongata
• pons

Answer 12

medulla oblongata

Question 13

An elevated ridge of the cortex is called a ________.

(One answer)

• suicus
• fissure
• furrow
• gyrus

Answer 13

gyrus

Question 14

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

(One answer)

• oligodendrocytes
• astrocytes
• Schwann cells
• ependymal cells

Answer 14

ependymal cells

Question 15

Which of the following is the best description of the function of region B?

(One answer)

• Region B coordinates the movement of several muscle groups into complex tasks.
• Region B contains neurons receiving somatosensory input from the thalamus.
• Region B is responsible for learning, working memory, judgement, reasoning, persistence, and planning.
• Region B includes neurons whose axons carry motor commands from the cerebrum.

Answer 15

Region B includes neurons whose axons carry motor commands from the cerebrum.

Question 16

The frontal lobe is separated from the temporal lobe by the ______.

(One answer)

• central sulcus
• cranial fossa
• lateral sulcus
• longitudinal fissure

Answer 16

lateral sulcus

Question 17

Which of the following would you NOT find in normal cerebrospinal fluid?

(One answer)

• protein
• potassium
• red blood cells
• glucose

Answer 17

red blood cells

Question 18

Which of the following is not associated with the parasympathetic division of the autonomic nervous system (ANS)?

(One answer)

• resting
• energy conservation
• emergency action
• digesting

Answer 18

emergency action

Question 19

A postsynaptic cell can be a neuron, a muscle cell, or a secretory cell. What is an example of a presynaptic cell?

(One answer)

• a secretory cell
• a muscle cell
• a neuron
• a Schwann cell

Answer 19

a neuron

Rationale: A neuron is the only type of presynaptic cell. Neurons release neurotransmitters, effectively changing an electrical signal or action potential into a chemical signal that can communicate across the synaptic cleft to the postsynaptic cell.

Question 20

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

(One answer)

• chemically gated channels
• Vesicles filled with neurotransmitter
• axon terminal
• calcium channels

Answer 20

chemically gated channels

Rationale: Neurotransmitter binds to receptors on the postsynaptic cell. These chemically gated channels open, allowing the transfer of the “signal” from a presynaptic neuron to the postsynaptic cell.

Question 21

What is the role of calcium in synaptic activity?

(One answer)

• Calcium influx into the synaptic terminal causes vesicle fusion.
• Calcium degrades neurotransmitter in the synaptic cleft.
• Calcium influx into the axon causes an action potential to propagate into the synaptic terminal.
• Calcium diffuses across the synaptic cleft and binds to receptors on the postsynaptic neuron.

Answer 21

Calcium influx into the synaptic terminal causes vesicle fusion.

Rationale: When an action potential reaches the synaptic terminal, voltage-gated channels open and calcium enters the cell. Calcium causes vesicles to fuse with the presynaptic membrane and release neurotransmitter into the synaptic cleft.

Question 22

What is the direct role of neurotransmitter at a chemical synapse?

(One answer)

• Neurotransmitter causes a graded potential in the postsynaptic cell.
• Neurotransmitter causes vesicles to fuse with the presynaptic membrane.
• Neurotransmitter causes calcium to flood into the presynaptic cell.
• Neurotransmitter binds to receptors on the postsynaptic cell membrane and allows ions to diffuse across the membrane.

Answer 22

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

Rationale: Neurotransmitter leaves the presynaptic neuron by exocytosis and binds receptors on the postsynaptic cell membrane, opening the channels. When ions enter the postsynaptic cell, a graded potential takes place.

Question 23

Neurotransmitter is released from presynaptic neurons through what mechanism?

(One answer)

• exocytosis
• pinocytosis
• phagocytosis
• endocytosis

Answer 23

exocytosis

Rationale: Neurotransmitter molecules are released from vesicles that fuse with the plasma membrane through exocytosis. Note that “exo-“ means “outside” and “cytosis” means “cell.” Once released, neurotransmitter diffuses across the synaptic cleft.

Question 24

What type of channel on the postsynaptic membrane binds neurotransmitter?

(One answer)

• a chemically gated channel
• a leakage channel
• a mechanically gated channel
• a voltage-gated channel

Answer 24

a chemically gated channel

Rationale: Chemically gated channels bind a specific chemical, which causes the channel to open. At chemical synapses, neurotransmitter molecules are released by the presynaptic neuron and bind to chemically gated channels on the postsynaptic cell membrane. The opening of these channels allows ions to diffuse across the membrane, causing a graded potential in the postsynaptic cell.

Question 25

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

(One answer)

• reuptake and degradation
• exocytosis and degradation
• excitation and degradation
• reuptake and inhibition

Answer 25

reuptake and degradation

Rationale: To terminate neurotransmitter effects, neurotransmitter molecules must be removed from the synaptic cleft. Reuptake does this by moving neurotransmitter back into the presynaptic neuron. Diffusion causes neurotransmitter to drift away from the synaptic cleft. Degradation occurs when enzymes break down neurotransmitter. As long as neurotransmitter molecules remain in the synaptic cleft, the chemically gated channels on the postsynaptic cell will continue to bind them and cause graded potentials.

Question 26

Events that occur during synaptic activity are listed here, but they are arranged in an incorrect order. Choose the correct order of these events below.

(One answer)

• (a) Voltage-gated calcium channels open (e) Neurotransmitter released into the synaptic cleft (c) Action potential arrives at axon terminal (b) Neurotransmitter binds to receptors (f) Graded potential generated in postsynaptic cell (d) Neurotransmitter is removed from the synaptic cleft
• (d) Neurotransmitter is removed from the synaptic cleft (b) Neurotransmitter binds to receptors (f) Graded potential generated in postsynaptic cell (c) Action potential arrives at axon terminal (a) Voltage-gated calcium channels open (e) Neurotransmitter released into the synaptic cleft
• (c) Action potential arrives at axon terminal (a) Voltage-gated calcium channels open (e) Neurotransmitter released into synaptic cleft (b) Neurotransmitter binds to receptors (f) Graded potential generated in postsynaptic cell (d) Neurotransmitter is removed from the synaptic cleft
• (c) Action potential arrives at axon terminal (a) Voltage-gated calcium channels open (e) Neurotransmitter released into the synaptic cleft (d) Neurotransmitter is removed from the synaptic cleft (b) Neurotransmitter binds to receptors (f) Graded potential generated in postsynaptic cell

Answer 26

(c) Action potential arrives at axon terminal (a) Voltage-gated calcium channels open (e) Neurotransmitter released into synaptic cleft (b) Neurotransmitter binds to receptors (f) Graded potential generated in postsynaptic cell (d) Neurotransmitter is removed from the synaptic cleft

Rationale: The correct sequence starts with a neural signal at the presynaptic cell, followed by the release of neurotransmitter, the creation of a graded potential in the postsynaptic cell, and degradation of the neurotransmitters. Neurotransmitters transfer information between a neuron and a postsynaptic cell. This process gets a “message” across a physical separation much like sending a text to your friend who is across town.

Question 27

Label the following image in the correct order from top to bottom

• Receptor in viscera
• Integration center
• Visceral sensory neuron
• Response
• Visceral effector
• Motor neuron

Answer 27

• Receptor in viscera
• Visceral sensory neuron
• Integration center
• Motor neuron
• Visceral effector
• Response

Question 28

The brachial plexus can be palpated at the lower lateral border of the sternocleidomastoid muscle. Injury to the brachial plexus could cause weakness or paralysis to all of the following EXCEPT the ______.

(One answer)

• muscles that flex the wrist and fingers
• tbiceps brachii muscle
• sternocleidomastoid muscle
• deltoid muscle

Answer 28

sternocleidomastoid muscle

Rationale: The sternocleidomastoid muscle is innervated by the accessory cranial nerve and branches of cervical spinal nerves C2 and C3.

Question 29

What differentiates an autonomic reflex from a somatic reflex?

(One answer)

• a single sensory neuron in the sensory pathway
• presence of a sensory receptor
• an integration center
• a two-neuron motor pathway

Answer 29

a two-neuron motor pathway

Rationale: Visceral reflex arcs have essentially the same components as somatic reflex arcs–receptor, sensory neuron, integration center, motor neuron, and effector. A key difference is that a visceral reflex arc has two neurons in its (autonomic) motor component, whereas the somatic reflex arc has a single (somatic) motor neuron.

Question 30

The adrenal medulla secretes epinephrine during sympathetic stimulation. Which of the following statements describes why epinephrine would increase the sympathetic response?

(One answer)

• Epinephrine increases the action of pre- and postganglionic axons.
• The same receptors that respond to norepinephrine also respond to epinephrine, increasing the action of both.
• Epinephrine binds to a separate receptor than norepinephrine, which increases the sympathetic response.
• Epinephrine has no effect on sympathetic targets.

Answer 30

The same receptors that respond to norepinephrine also respond to epinephrine, increasing the action of both.

Rationale: There is no separate receptor for epinephrine. It enhances the sympathetic pathways because it binds to the same receptors as norepinephrine.

Question 31

Match these prefixes to their meanings in the image below.

Answer 31

The prefix mening- means meninges.
The prefix photo- means light.
The prefix chem- means chemical.
The prefix crani- means skull.

Question 32

Match these vocabulary terms to their meanings in the image below.

Answer 32

The part of a spinal nerve that innervates the meninges is the meningeal branch.

The senses of taste and smell use chemoreceptors to detect and process taste and smell information.

Nerves that emerge from the base of the brain and pass through the skull are cranial nerves.

Receptors that respond to light are photoreceptor.

Question 33

Assume that the triangular and circular molecules shown in the illustration represent specific neurotransmitters. Which of the following best describes the effect on the heart of neurotransmitters released from the postganglionic neurons of B and C?

(One answer)

• B and C would act in synergy to increase heart rate and contraction force.
• B would increase heart rate, while C would decrease it.
• B and C would act in synergy to decrease heart rate and contraction force.
• C would increase heart rate, while B would decrease it.

Answer 33

B would increase heart rate, while C would decrease it.

Rationale: Sympathetic stimulation would increase heart rate when under stress, while parasympathetic stimulation would decrease heart rate during “rest and digest.” Parasympathetic ganglia are within or near effector organs, while sympathetic ganglia lie nearer to the CNS. Sympathetic postganglionic neurons secrete a different neurotransmitter than somatic and parasympathetic neurons.

Question 34

Once a preganglionic axon reaches a trunk ganglion, one of three things can happen to the axon. Which of the following is NOT one of these three things?

(One answer)

• The axon can ascend or descend the sympathetic trunk to synapse in another trunk ganglion.
• The axon can pass through the trunk ganglion and emerge from the sympathetic trunk without synapsing.
• The axon can course back into the spinal cord to synapse with preganglionic neurons in a different spinal segment.
• The axon can synapse with a ganglionic neuron in the same trunk ganglion.

Answer 34

The axon can course back into the spinal cord to synapse with preganglionic neurons in a different spinal segment.

Rationale: Preganglionic axons do not pass back into the spinal cord.

Question 35

Which of the following target organs/systems is affected by the sympathetic nervous system but is NOT affected by the parasympathetic nervous system?

(One answer)

• salivary glands
• gallbladder
• cellular metabolism
• lungs

Answer 35

cellular metabolism

Rationale: Preganglionic sympathetic fibers stimulate the adrenal medulla to secrete epinephrine into the bloodstream during “fight-or-flight” situations (such as exercise). In turn, epinephrine increases cellular metabolism (metabolic rate).

Question 36

Which of the following is an effect of norepinephrine binding to beta 2 adrenergic receptors?

(One answer)

• an increase in heart rate
• vasoconstriction
• vasodilation
• lipolysis

Answer 36

vasodilation

Rationale: The binding of norepinephrine to the beta 2 adrenergic receptors in blood vessels causes vasodilation.