Question 1

The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletal muscle is called the:
A) afferent nervous system.
B) sympathetic nervous system.
C) parasympathetic nervous system.
D) somatic motor nervous system.
E) autonomic nervous system.

Accepted Answer

The somatic motor nervous system is the portion of the peripheral nervous system that controls voluntary movement of skeletal muscles. A is incorrect because the afferent nervous system is responsible for carrying sensory information from the body to the central nervous system. B and C are incorrect because both the sympathetic and parasympathetic nervous systems are part of the autonomic nervous system, which controls involuntary functions of the body such as heart rate and digestion.

Question 2

The lipid portion of a cell's plasma membrane constitutes a barrier to current.

Accepted Answer

The lipid portion of a cell's plasma membrane is made of phospholipids that form a bilayer which acts as a barrier to current flow. This plays an important role in maintaining the transmembrane potential and regulating the movement of ions and molecules across the membrane.

Question 3

The cerebellum:
A) is important for coordinating body movement.
B) is the gray matter covering the entire surface of the brain.
C) is the same thing as the brain stem.
D) is in the anterior portion of the brain, just above the eyes.
E) is one of the basal nuclei that is found deep inside the cerebrum.

Accepted Answer

The cerebellum is known for its role in coordinating body movement, among other functions such as motor learning and balance. It is located in the posterior portion of the brain, below the occipital lobes.

Question 4

Which is a FALSE statement about the cerebrospinal fluid?
A) It has the same composition as blood plasma.
B) It acts as a cushion for the brain and spinal cord.
C) It is secreted by cells lining the ventricles of the brain.
D) It circulates within and between brain ventricles and surrounds the spinal cord.
E) It is in diffusion equilibrium with the extracellular fluid of the central nervous system.

Accepted Answer

The cerebrospinal fluid does not have the same composition as blood plasma. It differs in the concentrations of ions and proteins, among other components.

Question 5

During a hyperpolarizing graded potential, positively charged ions flow away from the site of the initial hyperpolarization on the outside of membrane and toward this site on the inside.

Accepted Answer

The answer of During a hyperpolarizing graded potential, positively charged...

Question 6

Ions other than K⁺ play no role in generating the resting membrane potential of a cell.

Accepted Answer

While K⁺ are the primary ions involved in generating the resting membrane potential, other ions such as Cl- and Ca2+ can also play a role.

Question 7

Synthesis of neuropeptides differs from that of other neurotransmitters because it:
A) takes place in the axon terminals of neurons.
B) takes place in the cell bodies of neurons.
C) takes place on ribosomes in the postsynaptic cell's membrane.
D) uses amino acids as precursor molecules.
E) only takes place at synapses outside the central nervous system.

Accepted Answer

Neuropeptides are synthesized in the cell bodies of neurons, unlike many other neurotransmitters that are synthesized in the axon terminals. This is because neuropeptides are synthesized as larger precursor proteins on ribosomes and then processed into their active form, a process that occurs in the cell body before they are transported to the axon terminals.

Question 8

Drug X interferes with the action of norepinephrine at synapses. Which of the following mechanisms would NOT explain the effects of X?
A) X inhibits synthesis of norepinephrine at the axon terminal.
B) X inhibits norepinephrine release from the terminal.
C) X blocks reuptake of norepinephrine by the terminal.
D) X is an adrenergic receptor antagonist.
E) X stimulates the catabolism of norepinephrine.

Accepted Answer

Blocking the reuptake of norepinephrine would increase its action at the synapse, not interfere with it.

Question 9

Which of the following is NOT characteristic of the sympathetic division of the autonomic nervous system?
A) Preganglionic neurons tend to be long, with the ganglion located in or near the effector target tissue(s).
B) Preganglionic neurons are short and synapse in ganglia located near the spinal cord.
C) Preganglionic neurons release acetylcholine at synapses with postganglionic neurons.
D) Postganglionic neurons release norepinephrine at their neuroeffector junctions.
E) Postganglionic neuron cell bodies are located in the collateral chain ganglia (sympathetic trunk).

Accepted Answer

In the sympathetic division of the autonomic nervous system, preganglionic neurons are typically short, and the ganglia where they synapse are located close to the spinal cord, not in or near the effector target tissues.

Question 10

The maintenance of a resting potential in a neuron depends indirectly upon the functioning of the Na⁺, K⁺-ATPase pumps in the membrane.

Accepted Answer

The Na+/K+ ATPase pumps are responsible for maintaining the concentration gradients of sodium and potassium ions across the membrane, which is necessary for establishing and maintaining the resting potential in a neuron.

Question 11

The region of the brain that is the most important control area for homeostatic regulation of the internal environment is:
A) the thalamus.
B) the hippocampus.
C) the cerebrum.
D) the cerebellum.
E) the hypothalamus.

Accepted Answer

The hypothalamus is the most important control area for homeostatic regulation of the internal environment. It plays a key role in regulating body temperature, thirst, hunger, and many other important physiological processes. It is located at the base of the brain and communicates with other regions of the brain and the rest of the body to maintain a stable internal environment.

Question 12

A graded potential in a membrane results in an electric current along an adjacent area of membrane and this current diminishes with distance from the site of the initial potential change.

Accepted Answer

Graded potentials result in local currents that decrease in strength as they spread out from the site of the initial potential change.

Question 13

Because so many Na⁺ ions move into a cell during an action potential and so many K⁺ ions move out, no further action potentials can be generated in a given membrane until the Na⁺, K⁺-ATPase pumps can restore the concentration gradient.

Accepted Answer

The Na⁺, K⁺-ATPase pumps help restore ion gradients over time, but action potentials can still occur due to the rapid opening and closing of ion channels, not solely dependent on the pump's activity.

Question 14

The central nervous system includes the:
A) afferent nerves and spinal cord.
B) efferent nerves and spinal cord.
C) autonomic nervous system and the brain.
D) brain stem and the autonomic nervous system.
E) brain and spinal cord.

Accepted Answer

The central nervous system includes the brain and spinal cord.

Question 15

Which of the following kinds of neurons is NOT generally cholinergic?
A) somatic motor neurons
B) postganglionic sympathetic neurons
C) postganglionic parasympathetic neurons
D) preganglionic sympathetic neurons
E) preganglionic parasympathetic neurons

Accepted Answer

Postganglionic sympathetic neurons are generally adrenergic, releasing norepinephrine, rather than cholinergic.

Question 16

Which best describes the reticular formation of the brain?
A) It is mainly involved in motor coordination and balance.
B) It is the master endocrine gland of the brain.
C) It is primarily responsible for visual perception.
D) It integrates information from all regions of the CNS, and incorporates the mechanisms that regulate sleep and wakefulness.
E) It is the primary synaptic relay station for sensory information entering the CNS.

Accepted Answer

The reticular formation is responsible for integrating information from all regions of the CNS and contains the mechanisms that regulate sleep and wakefulness. It does play a role in motor coordination and balance, but this is not its primary function. It is not the master endocrine gland of the brain nor is it primarily responsible for visual perception. It is also not the primary synaptic relay station for sensory information entering the CNS.

Question 17

A myelinated axon is shielded from direct contact with the extracellular fluid all along its length.

Accepted Answer

Myelinated axons have gaps known as nodes of Ranvier where the axon is exposed to the extracellular fluid, allowing for ion exchange necessary for the propagation of action potentials.

Question 18

Postganglionic neuron cell bodies of the autonomic nervous system have which category of neurotransmitter receptor?
A) Adrenergic receptors
B) Serotonin receptors
C) Muscarinic acetylcholine receptors
D) Nicotinic acetylcholine receptors
E) Dopamine receptors

Accepted Answer

The answer of Postganglionic neuron cell bodies of the autonomic...

Question 19

The ________________ is best described as "an interconnected group of brain structures including parts of the frontal lobe-cortex, temporal lobe, thalamus, and hypothalamus, that is associated with learning, emotional experience, and behavior?"
A) diencephalon
B) cerebrum
C) limbic system
D) reticular formation
E) cerebellum

Accepted Answer

The description given matches the anatomical and functional characteristics of the limbic system. The diencephalon, cerebrum, reticular formation, and cerebellum are also important brain structures, but they are not specifically associated with learning, emotional experience, and behavior in the way that the limbic system is.

Question 20

Which of the following does NOT result from the binding of nicotine with nicotinic acetylcholine receptors?
A) a mild form of skeletal muscle paralysis that creates a more relaxed state
B) signal transmission at neuromuscular junctions
C) generation of excitatory signals within autonomic ganglia
D) the release of norepinephrine, dopamine, and epinephrine
E) facilitation of the release of multiple neurotransmitters within the brain, including the "reward pathway" involving dopamine

Accepted Answer

The binding of nicotine with nicotinic acetylcholine receptors can result in signal transmission at neuromuscular junctions, generation of excitatory signals within autonomic ganglia, the release of norepinephrine, dopamine, and epinephrine, and facilitation of the release of multiple neurotransmitters within the brain. However, it does not result in a mild form of skeletal muscle paralysis that creates a more relaxed state.

Quiz 6: Neuronal Signaling and the Structure of the Nervous System

The portion of the peripheral nervous system that is composed of nerve fibers that innervate skeletal muscle is called the:

The lipid portion of a cell's plasma membrane constitutes a barrier to current.

The cerebellum:

Which is a FALSE statement about the cerebrospinal fluid?

During a hyperpolarizing graded potential, positively charged ions flow away from the site of the initial hyperpolarization on the outside of membrane and toward this site on the inside.

Ions other than K+ play no role in generating the resting membrane potential of a cell.

Synthesis of neuropeptides differs from that of other neurotransmitters because it:

Drug X interferes with the action of norepinephrine at synapses. Which of the following mechanisms would NOT explain the effects of X?

Which of the following is NOT characteristic of the sympathetic division of the autonomic nervous system?

The maintenance of a resting potential in a neuron depends indirectly upon the functioning of the Na+, K+-ATPase pumps in the membrane.

The region of the brain that is the most important control area for homeostatic regulation of the internal environment is:

A graded potential in a membrane results in an electric current along an adjacent area of membrane and this current diminishes with distance from the site of the initial potential change.

Because so many Na+ ions move into a cell during an action potential and so many K+ ions move out, no further action potentials can be generated in a given membrane until the Na+, K+-ATPase pumps can restore the concentration gradient.

The central nervous system includes the:

Which of the following kinds of neurons is NOT generally cholinergic?

Which best describes the reticular formation of the brain?

A myelinated axon is shielded from direct contact with the extracellular fluid all along its length.

Postganglionic neuron cell bodies of the autonomic nervous system have which category of neurotransmitter receptor?

The ________________ is best described as "an interconnected group of brain structures including parts of the frontal lobe-cortex, temporal lobe, thalamus, and hypothalamus, that is associated with learning, emotional experience, and behavior?"

Which of the following does NOT result from the binding of nicotine with nicotinic acetylcholine receptors?

Ions other than K⁺ play no role in generating the resting membrane potential of a cell.

The maintenance of a resting potential in a neuron depends indirectly upon the functioning of the Na⁺, K⁺-ATPase pumps in the membrane.

Because so many Na⁺ ions move into a cell during an action potential and so many K⁺ ions move out, no further action potentials can be generated in a given membrane until the Na⁺, K⁺-ATPase pumps can restore the concentration gradient.