Question 1

Which would result from an increase in the extracellular concentration of K+ above normal?

Accepted Answer

A) depolarization of resting nerve cells 
B) hyperpolarization of resting nerve cells 
C) The potassium equilibrium potential of nerve cells would become more negative. 
D) The sodium equilibrium potential would become less positive. 
A) depolarization of resting nerve cells 
B) hyperpolarization of resting nerve cells 
C) The potassium equilibrium potential of nerve cells would become more negative. 
D) The sodium equilibrium potential would become less positive.

Question 2

Which is a FALSE statement about the cerebrospinal fluid?

Accepted Answer

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. 
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.

Question 3

Which of the following statements concerning the permeability of a typical neuron membrane at rest is true?

Accepted Answer

A) The permeability to Na+ is much greater than the permeability to K+. 
B)  All of the K+ channels in the membrane are open. 
C) The voltage-gated Na+ channels are in the inactivated state. 
D) Most of the voltage-gated Na+ channels are in the closed state. 
E) There is equal permeability to Na+ and K+. 
A) The permeability to Na+ is much greater than the permeability to K+. 
B)  All of the K+ channels in the membrane are open. 
C) The voltage-gated Na+ channels are in the inactivated state. 
D) Most of the voltage-gated Na+ channels are in the closed state. 
E) There is equal permeability to Na+ and K+.

Question 4

Which is one of the most abundant excitatory neurotransmittors in the CNS?

Accepted Answer

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

Question 5

The sympathetic division of the autonomic nervous system is arranged so that it acts largely as a unit,whereas the components of the parasympathetic division generally act as discreet,independent components.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following statements about the phases of a neuronal action potential is true?

Accepted Answer

A) During the after-hyperpolarization phase,the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. 
B) During the after-hyperpolarization phase,the permeability of the membrane to potassium ions is greater than its permeability at rest. 
C) During the repolarizing phase,the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. 
D) Potassium channels inactivate during the depolarization phase. 
E) Repolarizing to negative membrane potentials causes the sodium channels to inactivate. 
A) During the after-hyperpolarization phase,the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. 
B) During the after-hyperpolarization phase,the permeability of the membrane to potassium ions is greater than its permeability at rest. 
C) During the repolarizing phase,the permeability of the membrane to sodium ions is greater than its permeability to potassium ions. 
D) Potassium channels inactivate during the depolarization phase. 
E) Repolarizing to negative membrane potentials causes the sodium channels to inactivate.

Question 7

The efferent division of the peripheral nervous system consists of the somatic nervous system and the autonomic nervous system.

Accepted Answer

A) True 
 B)False

Question 8

Which is TRUE about the initial segment of an axon?

Accepted Answer

A) Its threshold potential is more positive than that of the cell body and dendrites. 
B) Its threshold potential is more negative than that of the cell body and dendrites. 
C) Synapses far from the initial segment are more effective in influencing whether an action potential will be generated in the axon than are synapses close to the initial segment. 
D) It is the region where neurotransmitter vesicles are docked and ready to be released by exocytosis. 
E) It can only conduct graded potentials because it lacks voltage-gated Na+ channels. 
A) Its threshold potential is more positive than that of the cell body and dendrites. 
B) Its threshold potential is more negative than that of the cell body and dendrites. 
C) Synapses far from the initial segment are more effective in influencing whether an action potential will be generated in the axon than are synapses close to the initial segment. 
D) It is the region where neurotransmitter vesicles are docked and ready to be released by exocytosis. 
E) It can only conduct graded potentials because it lacks voltage-gated Na+ channels.

Question 9

The basal ganglia are important subcortical nuclei in the cerebrum.

Accepted Answer

A) True 
 B)False

Question 10

The regions of axon membrane that lie between regions of myelin are the

Accepted Answer

A) islets of Langerhans. 
B) nodes of Ranvier. 
C) synaptic membranes. 
D) glial cells. 
E) dens of iniquities. 
A) islets of Langerhans. 
B) nodes of Ranvier. 
C) synaptic membranes. 
D) glial cells. 
E) dens of iniquities.

Question 11

The Na+ and K+ channels that open during an action potential are voltage regulated,both opening in response to depolarization of the membrane.

Accepted Answer

A) True 
 B)False

Question 12

Acetylcholine is the main neurotransmitter released by:

Accepted Answer

A) preganglionic sympathetic neurons and cells of the adrenal medulla. 
B) cells of the adrenal medulla and postganglionic parasympathetic neurons. 
C) motor neurons and postganglionic sympathetic neurons. 
D) preganglionic sympathetic neurons and postganglionic sympathetic neurons. 
E) preganglionic sympathetic neurons and motor neurons. 
A) preganglionic sympathetic neurons and cells of the adrenal medulla. 
B) cells of the adrenal medulla and postganglionic parasympathetic neurons. 
C) motor neurons and postganglionic sympathetic neurons. 
D) preganglionic sympathetic neurons and postganglionic sympathetic neurons. 
E) preganglionic sympathetic neurons and motor neurons.

Question 13

The difference in electrical charge between two points:

Accepted Answer

A) is called the potential difference between those points. 
B) is called the diffusion potential between those points. 
C)  is called the the current,and is expressed in the units of millimoles. 
D) is the same for all ions. 
A) is called the potential difference between those points. 
B) is called the diffusion potential between those points. 
C)  is called the the current,and is expressed in the units of millimoles. 
D) is the same for all ions.

Question 14

Which of the following enzymes is important for the metabolism of catecholamines?

Accepted Answer

A) Tyrosine hydroxylase 
B) Acetylcholinesterase 
C) Superoxide dismutase 
D) Hydrocortinase 
E) Adenyl cyclase 
A) Tyrosine hydroxylase 
B) Acetylcholinesterase 
C) Superoxide dismutase 
D) Hydrocortinase 
E) Adenyl cyclase

Question 15

A presynaptic synapse:

Accepted Answer

A) is a synapse between an axon terminal and a dendrite that can be either excitatory or inhibitory. 
B)  is a synapse between an axon terminal and another axon's terminal that can be either excitatory or inhibitory. 
C) is any synapse onto a cell body,and they can be either stimulatory or inhibitory. 
D) is a synapse between an axon terminal and a dendrite of the same cell,which is always inhibitory. 
E) is a synapse between an axon terminal and another axon terminal that is always inhibitory. 
A) is a synapse between an axon terminal and a dendrite that can be either excitatory or inhibitory. 
B)  is a synapse between an axon terminal and another axon's terminal that can be either excitatory or inhibitory. 
C) is any synapse onto a cell body,and they can be either stimulatory or inhibitory. 
D) is a synapse between an axon terminal and a dendrite of the same cell,which is always inhibitory. 
E) is a synapse between an axon terminal and another axon terminal that is always inhibitory.

Question 16

Which is FALSE about the equilibrium potential of a given ion across a membrane?

Accepted Answer

A) It is a function of the concentration of that ion on both sides of the membrane. 
B) It is the potential at which there is no net movement of that ion across the membrane. 
C) It is the potential difference across the membrane at which an electric force favoring movement of the ion in one direction is equal in magnitude and opposite in direction to the diffusion force provided by the concentration difference of the ion across the membrane. 
D) A permeable ion will move in the direction that will tend to bring the membrane potential toward that ion's equilibrium potential. 
E) An anion that is in higher concentration inside the cell than outside the cell will have a negative eqilibrium potential. 
A) It is a function of the concentration of that ion on both sides of the membrane. 
B) It is the potential at which there is no net movement of that ion across the membrane. 
C) It is the potential difference across the membrane at which an electric force favoring movement of the ion in one direction is equal in magnitude and opposite in direction to the diffusion force provided by the concentration difference of the ion across the membrane. 
D) A permeable ion will move in the direction that will tend to bring the membrane potential toward that ion's equilibrium potential. 
E) An anion that is in higher concentration inside the cell than outside the cell will have a negative eqilibrium potential.

Question 17

An inhibitory postsynaptic potential:

Accepted Answer

A)  is produced by simultaneous increases in permeability to both Na+ and K+. 
B) occurs when a ligand-gated ion channel increases its permeability to K+. 
C) is a small depolarization in a postsynaptic cell. 
D) can be summed with other IPSPs to trigger an action potential in the postsynaptic cell. 
E) is produced by an increase in permeability to only Na+. 
A)  is produced by simultaneous increases in permeability to both Na+ and K+. 
B) occurs when a ligand-gated ion channel increases its permeability to K+. 
C) is a small depolarization in a postsynaptic cell. 
D) can be summed with other IPSPs to trigger an action potential in the postsynaptic cell. 
E) is produced by an increase in permeability to only Na+.

Question 18

Which is FALSE about interneurons?

Accepted Answer

A) They receive synaptic input from other other neurons in the CNS. 
B) They sum excitatory and inhibitory synaptic inputs. 
C) They deliver synaptic input on other neurons. 
D)  They make synapses on effector organs in the PNS. 
E) They can transmit information between afferent neurons and efferent neurons. 
A) They receive synaptic input from other other neurons in the CNS. 
B) They sum excitatory and inhibitory synaptic inputs. 
C) They deliver synaptic input on other neurons. 
D)  They make synapses on effector organs in the PNS. 
E) They can transmit information between afferent neurons and efferent neurons.

Question 19

A postsynaptic neuron has three presynaptic inputs - from neurons X,Y,and Z.When X and Y are stimulated simultaneously and repeatedly,the postsynaptic neuron reaches threshold and undergoes an action potential.When X and Z are stimulated simultaneously,however,there is no change in the membrane potential of the postsynaptic neuron.The simultaneous stimulation of X and Y is an example of

Accepted Answer

A) temporal summation. 
B) presynaptic inhibition. 
C) spatial summation. 
D) neuronal divergence. 
E) presynaptic facilitation. 
A) temporal summation. 
B) presynaptic inhibition. 
C) spatial summation. 
D) neuronal divergence. 
E) presynaptic facilitation.

Question 20

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

A) True 
 B)False

Which would result from an increase in the extracellular concentration of K⁺ above normal?

Which is a FALSE statement about the cerebrospinal fluid?

Which of the following statements concerning the permeability of a typical neuron membrane at rest is true?

Which is one of the most abundant excitatory neurotransmittors in the CNS?

The sympathetic division of the autonomic nervous system is arranged so that it acts largely as a unit,whereas the components of the parasympathetic division generally act as discreet,independent components.

Which of the following statements about the phases of a neuronal action potential is true?

The efferent division of the peripheral nervous system consists of the somatic nervous system and the autonomic nervous system.

Which is TRUE about the initial segment of an axon?

The basal ganglia are important subcortical nuclei in the cerebrum.

The regions of axon membrane that lie between regions of myelin are the

The Na⁺ and K⁺ channels that open during an action potential are voltage regulated,both opening in response to depolarization of the membrane.

Acetylcholine is the main neurotransmitter released by:

The difference in electrical charge between two points:

Which of the following enzymes is important for the metabolism of catecholamines?

A presynaptic synapse:

Which is FALSE about the equilibrium potential of a given ion across a membrane?

An inhibitory postsynaptic potential:

Which is FALSE about interneurons?

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.

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

Which would result from an increase in the extracellular concentration of K+ above normal?

Which is a FALSE statement about the cerebrospinal fluid?

Which of the following statements concerning the permeability of a typical neuron membrane at rest is true?

Which is one of the most abundant excitatory neurotransmittors in the CNS?

The sympathetic division of the autonomic nervous system is arranged so that it acts largely as a unit,whereas the components of the parasympathetic division generally act as discreet,independent components.

Which of the following statements about the phases of a neuronal action potential is true?

The efferent division of the peripheral nervous system consists of the somatic nervous system and the autonomic nervous system.

Which is TRUE about the initial segment of an axon?

The basal ganglia are important subcortical nuclei in the cerebrum.

The regions of axon membrane that lie between regions of myelin are the

The Na+ and K+ channels that open during an action potential are voltage regulated,both opening in response to depolarization of the membrane.

Acetylcholine is the main neurotransmitter released by:

The difference in electrical charge between two points:

Which of the following enzymes is important for the metabolism of catecholamines?

A presynaptic synapse:

Which is FALSE about the equilibrium potential of a given ion across a membrane?

An inhibitory postsynaptic potential:

Which is FALSE about interneurons?

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.

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

Which would result from an increase in the extracellular concentration of K⁺ above normal?

The Na⁺ and K⁺ channels that open during an action potential are voltage regulated,both opening in response to depolarization of the membrane.