Question 1

Which of the following statements about the refractory period of a membrane is true?

Accepted Answer

A) The absolute refractory period refers to the period of time during which another action potential cannot be initiated in that part of the membrane that is undergoing an action potential,no matter how great the strength of the stimulus. 
B) The relative refractory period refers to the period of time during which another action potential can be initiated in that part of the membrane that has just undergone an action potential if a stronger than normal stimulus is applied. 
C) The refractory period prevents the action potential from spreading back over the part of the membrane that just underwent an action potential. 
D) The refractory period places an upper limit on the frequency with which a nerve cell can conduct action potentials. 
E) All of the above choices are correct. 
A) The absolute refractory period refers to the period of time during which another action potential cannot be initiated in that part of the membrane that is undergoing an action potential,no matter how great the strength of the stimulus. 
B) The relative refractory period refers to the period of time during which another action potential can be initiated in that part of the membrane that has just undergone an action potential if a stronger than normal stimulus is applied. 
C) The refractory period prevents the action potential from spreading back over the part of the membrane that just underwent an action potential. 
D) The refractory period places an upper limit on the frequency with which a nerve cell can conduct action potentials. 
E) All of the above choices are correct. E

Question 2

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

Accepted Answer

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. 
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. C

Question 3

Which of the following is not true about axon transport?

Accepted Answer

A) It refers to the passage of materials from the cell body of a neuron to the axon terminals. 
B) It refers to the passage of materials from axon terminals to the cell body of a neuron. 
C) It refers to the transport of materials from the inside to the outside across the axonal membrane. 
D) It is especially important for maintaining the integrity of neurons with long axons. 
A) It refers to the passage of materials from the cell body of a neuron to the axon terminals. 
B) It refers to the passage of materials from axon terminals to the cell body of a neuron. 
C) It refers to the transport of materials from the inside to the outside across the axonal membrane. 
D) It is especially important for maintaining the integrity of neurons with long axons. C

Question 4

Which of the following statements about EPSPs is false?

Accepted Answer

A) They are produced by the opening of chemically-gated sodium channels. 
B) They transmit signals over relatively short distances. 
C)  They depolarize postsynaptic cell membranes. 
D) They are able to summate. 
E) They are always the same amplitude. 
A) They are produced by the opening of chemically-gated sodium channels. 
B) They transmit signals over relatively short distances. 
C)  They depolarize postsynaptic cell membranes. 
D) They are able to summate. 
E) They are always the same amplitude.

Question 5

Which of the following statements about acetylcholine is correct?

Accepted Answer

A) Acetylcholine binds to nicotinic and muscarinic receptors. 
B) Acetylcholine binds to adrenergic receptors. 
C) Acetylcholine synthesis is catalyzed by acetylcholinesterase 
D) Acetylcholine is the neurotransmitter released by most sympathetic postganglionic neurons. 
E) Acetylcholine is generally transported back into presynaptic nerve terminals without being enzymatically degraded. 
A) Acetylcholine binds to nicotinic and muscarinic receptors. 
B) Acetylcholine binds to adrenergic receptors. 
C) Acetylcholine synthesis is catalyzed by acetylcholinesterase 
D) Acetylcholine is the neurotransmitter released by most sympathetic postganglionic neurons. 
E) Acetylcholine is generally transported back into presynaptic nerve terminals without being enzymatically degraded.

Question 6

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

Accepted Answer

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 
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

Question 7

According to the equation expressed as Ohm's law,which of these would cause the greatest increase in current?

Accepted Answer

A) doubling both voltage and resistance 
B) reducing both voltage and resistance by half 
C) doubling voltage and reducing resistance by half 
D) reducing voltage by half and doubling resistance 
E) quadrupling both voltage and resistance 
A) doubling both voltage and resistance 
B) reducing both voltage and resistance by half 
C) doubling voltage and reducing resistance by half 
D) reducing voltage by half and doubling resistance 
E) quadrupling both voltage and resistance

Question 8

Catecholamines are the most abundant neurotransmitters in the CNS.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following statements concerning the rate of action potential propagation is true?

Accepted Answer

A) It is faster in small-diameter axons than in large-diameter axons. 
B) It is faster for a strong stimulus than for a weak one. 
C) It is faster in myelinated axons than in nonmyelinated axons. 
D) It is faster in the dendrites than in the axon. 
E) It occurs at the same rate in all axons,regardless of their diameter. 
A) It is faster in small-diameter axons than in large-diameter axons. 
B) It is faster for a strong stimulus than for a weak one. 
C) It is faster in myelinated axons than in nonmyelinated axons. 
D) It is faster in the dendrites than in the axon. 
E) It occurs at the same rate in all axons,regardless of their diameter.

Question 10

Which must happen in order for an action potential to begin?

Accepted Answer

A) The membrane potential must be at the Na+ equilibrium potential. 
B) Na+ influx must exceed K+ efflux. 
C) The membrane must be out of the relative refractory period. 
D) Na+ channels must all be inactivated. 
E) Multiple inhibitory postsynaptic potentials (IPSPs)must summate. 
A) The membrane potential must be at the Na+ equilibrium potential. 
B) Na+ influx must exceed K+ efflux. 
C) The membrane must be out of the relative refractory period. 
D) Na+ channels must all be inactivated. 
E) Multiple inhibitory postsynaptic potentials (IPSPs)must summate.

Question 11

Which is TRUE about the resting membrane potential?

Accepted Answer

A) It requires very few ions to be distributed unevenly. 
B) It has the same value in all cells. 
C) It is oriented so that the cell's interior is positive with respect to the extracellular fluid. 
D) Only nerve and muscle cells have a potential difference across the membrane at rest. 
E) It is not altered by changing concentration gradients of permeating ions. 
A) It requires very few ions to be distributed unevenly. 
B) It has the same value in all cells. 
C) It is oriented so that the cell's interior is positive with respect to the extracellular fluid. 
D) Only nerve and muscle cells have a potential difference across the membrane at rest. 
E) It is not altered by changing concentration gradients of permeating ions.

Question 12

Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response to the arrival of an action potential in the axon terminal.

Accepted Answer

A) K+ 
B) Na+ 
C) Ca2+ 
D) ATP 
E) Cl- 
A) K+ 
B) Na+ 
C) Ca2+ 
D) ATP 
E) Cl-

Question 13

Which is TRUE about typical,resting neurons?

Accepted Answer

A) The plasma membrane is most permeable to sodium ions. 
B) The concentration of sodium ion is greater inside the cell than outside. 
C)  The permeability of the plasma membrane to potassium ions is much greater than its permeability to sodium ions. 
D) The plasma membrane is completely impermeable to sodium ions. 
E) The plasma membrane is completely impermeable to potassium ions. 
A) The plasma membrane is most permeable to sodium ions. 
B) The concentration of sodium ion is greater inside the cell than outside. 
C)  The permeability of the plasma membrane to potassium ions is much greater than its permeability to sodium ions. 
D) The plasma membrane is completely impermeable to sodium ions. 
E) The plasma membrane is completely impermeable to potassium ions.

Question 14

Serotonin:

Accepted Answer

A) acts as a neuromodulator. 
B) is a catecholamine neurotransmitter. 
C) is a neuropeptide. 
D) has an inhibitory effect on pathways that are involved in the control of muscles. 
E) has an excitatory effect on pathways that mediate sensations. 
A) acts as a neuromodulator. 
B) is a catecholamine neurotransmitter. 
C) is a neuropeptide. 
D) has an inhibitory effect on pathways that are involved in the control of muscles. 
E) has an excitatory effect on pathways that mediate sensations.

Question 15

Which of the following statements regarding neurotransmitters is TRUE?

Accepted Answer

A) Acetylcholine is broken down by enzymes present on postsynaptic cell membranes. 
B) Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cell membrane. 
C) Catecholamines are the most abundant neurotransmitters in the central nervous system. 
D) Opiate drugs,such as morphine,are antagonists of a class of neurotransmitters called endorphins. 
E) Gamma-aminobutyric acid (GAB
A) is a major excitatory transmitter in the central nervous system. 
A) Acetylcholine is broken down by enzymes present on postsynaptic cell membranes. 
B) Acetylcholine that is released at synapses binds to adrenergic receptors in the postsynaptic cell membrane. 
C) Catecholamines are the most abundant neurotransmitters in the central nervous system. 
D) Opiate drugs,such as morphine,are antagonists of a class of neurotransmitters called endorphins. 
E) Gamma-aminobutyric acid (GAB
A) is a major excitatory transmitter in the central nervous system.

Question 16

Which is most directly responsible for the falling (repolarizing)phase of the action potential?

Accepted Answer

A) Voltage-gated Na+ channels are opened. 
B) The Na+,K+ pump restores the ions to their original locations inside and outside of the cell. 
C) The permeability to Na+ increases greatly. 
D) ATPase destroys the energy supply that was maintaining the action potential at its peak. 
E) The permeability to K+ increases greatly while that to Na+ decreases. 
A) Voltage-gated Na+ channels are opened. 
B) The Na+,K+ pump restores the ions to their original locations inside and outside of the cell. 
C) The permeability to Na+ increases greatly. 
D) ATPase destroys the energy supply that was maintaining the action potential at its peak. 
E) The permeability to K+ increases greatly while that to Na+ decreases.

Question 17

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

A) True 
 B)False

Question 18

During the rising (depolarizing)phase of a neuronal action potential,

Accepted Answer

A) PK+ becomes much greater than PNa+. 
B) PNa+ becomes much greater than PK+. 
C) PK+ is the same as PNa+. 
D) Na+ efflux (flow out of the cell)occurs. 
E) K+ flows rapidly into the cell. 
A) PK+ becomes much greater than PNa+. 
B) PNa+ becomes much greater than PK+. 
C) PK+ is the same as PNa+. 
D) Na+ efflux (flow out of the cell)occurs. 
E) K+ flows rapidly into the cell.

Question 19

The frequency of action potentials in a postsynaptic cell is directly related to the degree of depolarization of the postsynaptic cell.

Accepted Answer

A) True 
 B)False

Question 20

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

A) True 
 B)False

Which of the following statements about the refractory period of a membrane is true?

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 true about axon transport?

Which of the following statements about EPSPs is false?

Which of the following statements about acetylcholine is correct?

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

According to the equation expressed as Ohm's law,which of these would cause the greatest increase in current?

Catecholamines are the most abundant neurotransmitters in the CNS.

Which of the following statements concerning the rate of action potential propagation is true?

Which must happen in order for an action potential to begin?

Which is TRUE about the resting membrane potential?

Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response to the arrival of an action potential in the axon terminal.

Which is TRUE about typical,resting neurons?

Serotonin:

Which of the following statements regarding neurotransmitters is TRUE?

Which is most directly responsible for the falling (repolarizing)phase of the action potential?

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.

During the rising (depolarizing)phase of a neuronal action potential,

The frequency of action potentials in a postsynaptic cell is directly related to the degree of depolarization of the postsynaptic cell.

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.

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

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

Which of the following statements about the refractory period of a membrane is true?

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 true about axon transport?

Which of the following statements about EPSPs is false?

Which of the following statements about acetylcholine is correct?

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

According to the equation expressed as Ohm's law,which of these would cause the greatest increase in current?

Catecholamines are the most abundant neurotransmitters in the CNS.

Which of the following statements concerning the rate of action potential propagation is true?

Which must happen in order for an action potential to begin?

Which is TRUE about the resting membrane potential?

Exocytosis of neurotransmitter into the synaptic cleft is triggered by an influx of ______ in response to the arrival of an action potential in the axon terminal.

Which is TRUE about typical,resting neurons?

Serotonin:

Which of the following statements regarding neurotransmitters is TRUE?

Which is most directly responsible for the falling (repolarizing)phase of the action potential?

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.

During the rising (depolarizing)phase of a neuronal action potential,

The frequency of action potentials in a postsynaptic cell is directly related to the degree of depolarization of the postsynaptic cell.

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.

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