Question 1

An action potential does not re-stimulate the adjacent membrane that was previously depolarized because

Accepted Answer

A) stimulation is inhibited by the myelin sheath. 
B) it is impossible for an action potential to be propagated along an axon toward the nerve cell body. 
C) the resting membrane potential of the axon is too positive. 
D) the resting membrane potential of the axon is too negative. 
E) that area of the membrane is in the absolutely refractory period. 
A) stimulation is inhibited by the myelin sheath. 
B) it is impossible for an action potential to be propagated along an axon toward the nerve cell body. 
C) the resting membrane potential of the axon is too positive. 
D) the resting membrane potential of the axon is too negative. 
E) that area of the membrane is in the absolutely refractory period.

Question 2

Which of the following is not known to be an important neurotransmitter in the CNS?

Accepted Answer

A) Dopamine 
B) Acetylcholine 
C) Morphine 
D) Glutamate 
E) Substance P 
A) Dopamine 
B) Acetylcholine 
C) Morphine 
D) Glutamate 
E) Substance P

Question 3

Spinal nerves are composed of the axons of both afferent and efferent neurons.

Accepted Answer

A) True 
 B)False

Question 4

The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane:

Accepted Answer

A) favors its movement into the cell at the resting membrane potential. 
B) favors its movement out of the cell at the resting membrane potential. 
C) is equal and opposite to the electrical potential acting on Na+ at the resting membrane potential. 
D) Is in the same direction as the diffusion potential due to the concentration gradient for K+. 
E) favors movement of Na+ in the opposite direction as the electrical potential acting on Na+ at the resting membrane potential. 
A) favors its movement into the cell at the resting membrane potential. 
B) favors its movement out of the cell at the resting membrane potential. 
C) is equal and opposite to the electrical potential acting on Na+ at the resting membrane potential. 
D) Is in the same direction as the diffusion potential due to the concentration gradient for K+. 
E) favors movement of Na+ in the opposite direction as the electrical potential acting on Na+ at the resting membrane potential.

Question 5

The main role of calcium ions at chemical synapses is to

Accepted Answer

A) depolarize the axon terminal of the presynaptic cell. 
B)  bind to neurotransmitter receptors on the postsynaptic cell. 
C) cause fusion of synaptic vesicles with the plasma membrane of the axon terminal. 
D) interfere with IPSPs in the postsynaptic cell. 
E) diffuse across the synaptic space and enter the postsynaptic cell. 
A) depolarize the axon terminal of the presynaptic cell. 
B)  bind to neurotransmitter receptors on the postsynaptic cell. 
C) cause fusion of synaptic vesicles with the plasma membrane of the axon terminal. 
D) interfere with IPSPs in the postsynaptic cell. 
E) diffuse across the synaptic space and enter the postsynaptic cell.

Question 6

SNARE receptor protein complexes in presynaptic neurons function as inhibitors of calcium transport to dampen or reduce the amount of neurotransmitter vesicles which participate in exocytosis.

Accepted Answer

A) True 
 B)False

Question 7

Responses made possible by motor signals transmitted by the parasympathetic nervous system tend to be displayed throughout the body simultaneously because there is much divergence of nerve pathways and close anatomical association between presynaptic neurons and their ganglia as well as accessory activity with the adrenal glands.

Accepted Answer

A) True 
 B)False

Question 8

Which of these would occur if the concentration of ATP were depleted in a typical nerve cell?

Accepted Answer

A) Resting membrane potential would become more negative. 
B) Resting membrane potential would become less negative. 
C) The concentration gradient for Na+ would remain the same. 
D) The resting membrane potential would eventually become positive inside with respect to outside. 
E) There would be no change in the resting membrane potential. 
A) Resting membrane potential would become more negative. 
B) Resting membrane potential would become less negative. 
C) The concentration gradient for Na+ would remain the same. 
D) The resting membrane potential would eventually become positive inside with respect to outside. 
E) There would be no change in the resting membrane potential.

Question 9

Ions other than Na+,K+,and Cl- play no role in generating the resting membrane potential of a cell.

Accepted Answer

A) True 
 B)False

Question 10

An action potential in a neuronal membrane differs from a graded potential in that:

Accepted Answer

A) an action potential requires the opening of Ca2+ channels,whereas a graded potential does not. 
B) an action potential is propagated without decrement,whereas a graded potential decrements with distance. 
C) an action potential has a threshold,whereas a graded potential is an all-or-none phenomenon. 
D) movement of Na+ and K+ across cell membranes mediate action potentials,while graded potentials do not involve movement of Na+ and K+. 
E) action potentials vary in size with the size of a stimulus,while graded potentials do not. 
A) an action potential requires the opening of Ca2+ channels,whereas a graded potential does not. 
B) an action potential is propagated without decrement,whereas a graded potential decrements with distance. 
C) an action potential has a threshold,whereas a graded potential is an all-or-none phenomenon. 
D) movement of Na+ and K+ across cell membranes mediate action potentials,while graded potentials do not involve movement of Na+ and K+. 
E) action potentials vary in size with the size of a stimulus,while graded potentials do not.

Question 11

Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z.Which will occur when action potentials are stimulated in neuron X?

Accepted Answer

A) Neuron Y will be inhibited from reaching the threshold to fire an action potential. 
B) The release of neurotransmitter by neuron Y will be inhibited. 
C) The synapse between neurons Y and Z will be changed from an excitatory synapse to an inhibitory one. 
D) Neurons Y and Z will both be more likely to reach threshold and fire an action potential. 
E) Neurons Y and Z will both be less likely to reach threshold and fire an action potential. 
A) Neuron Y will be inhibited from reaching the threshold to fire an action potential. 
B) The release of neurotransmitter by neuron Y will be inhibited. 
C) The synapse between neurons Y and Z will be changed from an excitatory synapse to an inhibitory one. 
D) Neurons Y and Z will both be more likely to reach threshold and fire an action potential. 
E) Neurons Y and Z will both be less likely to reach threshold and fire an action potential.

Question 12

The action potential elicited by a supra-threshold stimulus is larger than one elicited by a threshold stimulus.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following statements concerning the properties of action potentials is true?

Accepted Answer

A) The rate of propagation of an action potential down an axon is independent of stimulus strength. 
B) Action potentials can undergo summation. 
C) A supra-threshold stimulus can stimulate an action potential during the absolute refractory period. 
D) Action potentials generally propagate from the axon terminal toward the initial segment. 
E) Increasing the size of a stimulus will increase the amplitude of an action potential. 
A) The rate of propagation of an action potential down an axon is independent of stimulus strength. 
B) Action potentials can undergo summation. 
C) A supra-threshold stimulus can stimulate an action potential during the absolute refractory period. 
D) Action potentials generally propagate from the axon terminal toward the initial segment. 
E) Increasing the size of a stimulus will increase the amplitude of an action potential.

Question 14

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?"

Accepted Answer

A) diencephalon 
B) cerebrum 
C) limbic system 
D) reticular formation 
E) cerebellum 
A) diencephalon 
B) cerebrum 
C) limbic system 
D) reticular formation 
E) cerebellum

Question 15

Which is one of the major inhibitory neurotransmittors in the CNS?

Accepted Answer

A) Glutamate 
B) Dopamine 
C) Norepinephrine 
D) Gamma-aminobutyric acid (GAB
A)  
E) Beta-endorphin 
A) Glutamate 
B) Dopamine 
C) Norepinephrine 
D) Gamma-aminobutyric acid (GAB
A)  
E) Beta-endorphin

Question 16

The relative refractory period of an excitable membrane refers to the period of time during which no stimulus,however strong,will elicit a second action potential in the membrane.

Accepted Answer

A) True 
 B)False

Question 17

Dorsal root ganglia contain the cell bodies of efferent neurons.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

Alzheimer's disease is thought to involve primarily:

Accepted Answer

A) loss of neurons that secrete or respond to catecholamines. 
B) loss of adrenergic neurons. 
C) loss of cholinergic neurons. 
D) loss of neurons that secrete or respond to dopamine. 
E) tumors that produce excess serotonin. 
A) loss of neurons that secrete or respond to catecholamines. 
B) loss of adrenergic neurons. 
C) loss of cholinergic neurons. 
D) loss of neurons that secrete or respond to dopamine. 
E) tumors that produce excess serotonin.

Question 20

Preganglionic fibers of the parasympathetic division of the autonomic nervous system leave the CNS at the level of the brainstem and sacral portions of the spinal cord.

Accepted Answer

A) True 
 B)False

An action potential does not re-stimulate the adjacent membrane that was previously depolarized because

Which of the following is not known to be an important neurotransmitter in the CNS?

Spinal nerves are composed of the axons of both afferent and efferent neurons.

The diffusion potential due to the concentration gradient for Na⁺ across a nerve cell membrane:

The main role of calcium ions at chemical synapses is to

SNARE receptor protein complexes in presynaptic neurons function as inhibitors of calcium transport to dampen or reduce the amount of neurotransmitter vesicles which participate in exocytosis.

Which of these would occur if the concentration of ATP were depleted in a typical nerve cell?

Ions other than Na⁺,K⁺,and Cl^- play no role in generating the resting membrane potential of a cell.

An action potential in a neuronal membrane differs from a graded potential in that:

Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z.Which will occur when action potentials are stimulated in neuron X?

The action potential elicited by a supra-threshold stimulus is larger than one elicited by a threshold stimulus.

Which of the following statements concerning the properties of action potentials is true?

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 is one of the major inhibitory neurotransmittors in the CNS?

The relative refractory period of an excitable membrane refers to the period of time during which no stimulus,however strong,will elicit a second action potential in the membrane.

Dorsal root ganglia contain the cell bodies of efferent neurons.

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

Alzheimer's disease is thought to involve primarily:

Preganglionic fibers of the parasympathetic division of the autonomic nervous system leave the CNS at the level of the brainstem and sacral portions of the spinal cord.

Homeostasis: a Framework for Human Physiology

Chemical Composition of the Body

Cellular Structure, Proteins, and Metabolism

Movement of Molecules Across Cell Membranes

Control of Cells by Chemical Messengers

Sensory Physiology

Consciousness, the Brain, and Behavior

Muscle

Control of Body Movement

The Endocrine System

Cardiovascular Physiology

Respiratory Physiology

The Kidneys and Regulation of Water and Inorganic Ions

The Digestion and Absorption of Food

Regulation of Organic Metabolism and Energy Balance

Reproduction

Defense Mechanisms of the Body

Medical Physiology: Integration Using Clinical Cases

Filters

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

An action potential does not re-stimulate the adjacent membrane that was previously depolarized because

Which of the following is not known to be an important neurotransmitter in the CNS?

Spinal nerves are composed of the axons of both afferent and efferent neurons.

The diffusion potential due to the concentration gradient for Na+ across a nerve cell membrane:

The main role of calcium ions at chemical synapses is to

SNARE receptor protein complexes in presynaptic neurons function as inhibitors of calcium transport to dampen or reduce the amount of neurotransmitter vesicles which participate in exocytosis.

Which of these would occur if the concentration of ATP were depleted in a typical nerve cell?

Ions other than Na+,K+,and Cl- play no role in generating the resting membrane potential of a cell.

An action potential in a neuronal membrane differs from a graded potential in that:

Neuron X makes inhibitory axon-axon synaptic contact with neuron Y at the synapse of Y and neuron Z.Which will occur when action potentials are stimulated in neuron X?

The action potential elicited by a supra-threshold stimulus is larger than one elicited by a threshold stimulus.

Which of the following statements concerning the properties of action potentials is true?

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 is one of the major inhibitory neurotransmittors in the CNS?

The relative refractory period of an excitable membrane refers to the period of time during which no stimulus,however strong,will elicit a second action potential in the membrane.

Dorsal root ganglia contain the cell bodies of efferent neurons.

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

Alzheimer's disease is thought to involve primarily:

Preganglionic fibers of the parasympathetic division of the autonomic nervous system leave the CNS at the level of the brainstem and sacral portions of the spinal cord.

Homeostasis: a Framework for Human Physiology

Chemical Composition of the Body

Cellular Structure, Proteins, and Metabolism

Movement of Molecules Across Cell Membranes

Control of Cells by Chemical Messengers

Sensory Physiology

Consciousness, the Brain, and Behavior

Muscle

Control of Body Movement

The Endocrine System

Cardiovascular Physiology

Respiratory Physiology

The Kidneys and Regulation of Water and Inorganic Ions

The Digestion and Absorption of Food

Regulation of Organic Metabolism and Energy Balance

Reproduction

Defense Mechanisms of the Body

Medical Physiology: Integration Using Clinical Cases

Filters

The diffusion potential due to the concentration gradient for Na⁺ across a nerve cell membrane:

Ions other than Na⁺,K⁺,and Cl^- play no role in generating the resting membrane potential of a cell.