Question 1

The membrane is more permeable to K+ than to Na+

Accepted Answer

A)  at resting potential 
B)  during the rising phase of an action potential 
C)  during the rising phase of a graded potential 
D)  at resting potential and during the rising phase of an action potential 
E)  at resting potential and during the rising phase of a graded potential 
A)  at resting potential 
B)  during the rising phase of an action potential 
C)  during the rising phase of a graded potential 
D)  at resting potential and during the rising phase of an action potential 
E)  at resting potential and during the rising phase of a graded potential

Question 2

Assume that a hypothetical neuron has three presynaptic inputs: A and B are excitatory, and C is inhibitory. Indicate which of the following changes will take place.
 $\begin{array}{lr}
\text { 1. What would occur if both presynaptic }\\text { neurons } \mathrm{A} \text { and } \mathrm{C} \text { were fired simultaneously? }&\text { temporal summation }\_\_\_\
\text { 2. What would occur if presynaptic neuron } B\\text { were fired rapidly? }&\text { spatial summation }\_\_\_\
\text { 3. What would occur if both presynaptic }&\text { no change in potential of }\\text { neurons } \mathrm{A} \text { and } \mathrm{B} \text { were fired simultaneously? }&\text { the postsynaptic cell }\_\_\_
\end{array}$

Accepted Answer

The answer of Assume that a hypothetical neuron has three...

Question 3

Which statement about graded potentials is false?

Accepted Answer

A)  They are decremental. 
B)  They travel only short distances. 
C)  They are self-propagating. 
D)  They may contribute to the development of an action potential. 
E)  They travel in both directions along the membrane. 
A)  They are decremental. 
B)  They travel only short distances. 
C)  They are self-propagating. 
D)  They may contribute to the development of an action potential. 
E)  They travel in both directions along the membrane.

Question 4

What is responsible for development of the resting membrane potential?

Accepted Answer

A)  leak channels 
B)  gated channels 
C)  ion pumps 
D)  leak channels and gated channels 
E)  leak channels and ion pumps 
A)  leak channels 
B)  gated channels 
C)  ion pumps 
D)  leak channels and gated channels 
E)  leak channels and ion pumps

Question 5

A spike is another name for the axon of a neuron.

Accepted Answer

A) True 
 B)False

Question 6

The refractory period prevents action potentials from spreading back over the part of the membrane where the impulse has just passed.

Accepted Answer

A) True 
 B)False

Question 7

Oligodendrocytes are specialized to conduct electrical impulses to neurons.

Accepted Answer

A) True 
 B)False

Question 8

Presynaptic inhibition is brought about when dendrites of a postsynaptic neuron alter the signals sent from an axon terminal of a presynaptic neuron.

Accepted Answer

A) True 
 B)False

Question 9

Sequence the following events correctly. 
1.	Neurotransmitter diffuses across cleft.
2.	Calcium induces exocytosis of neurotransmitter.
3.	Permeability of postsynaptic membrane altered.
4.	Ion channels open.
5.	Neurotransmitter binds to receptor.

Accepted Answer

A)  1, 2, 3, 5, 4 
B)  1, 4, 3, 2, 5 
C)  2, 1, 5, 4, 3 
D)  3, 1, 4, 5, 2 
E)  5, 4, 3, 1, 2 
A)  1, 2, 3, 5, 4 
B)  1, 4, 3, 2, 5 
C)  2, 1, 5, 4, 3 
D)  3, 1, 4, 5, 2 
E)  5, 4, 3, 1, 2

Question 10

Complete each of the following statments.
A plasma membrane is polarized if it separates particles with an opposite ____________________.

Accepted Answer

The answer of Complete each of the following statments.
A plasma...

Question 11

A single neuron may be presynaptic to one group of neurons and postsynaptic to another group of neurons.

Accepted Answer

A) True 
 B)False

Question 12

Which statement is not accurate about the absolute refractory period?

Accepted Answer

A)  Another stimulus, regardless of its strength, cannot initiate another action potential during this period. 
B)  During this period, voltage-gated Na+ channels open, then close but are inactivated. 
C)  Immediately following this period, the membrane can experience another action potential if the stimulus is strong enough. 
D)  This period occurs during the after hyperpolarization phase of the action potential. 
E)  This period ensures a unidirectional spread of the action potential down a nerve fiber. 
A)  Another stimulus, regardless of its strength, cannot initiate another action potential during this period. 
B)  During this period, voltage-gated Na+ channels open, then close but are inactivated. 
C)  Immediately following this period, the membrane can experience another action potential if the stimulus is strong enough. 
D)  This period occurs during the after hyperpolarization phase of the action potential. 
E)  This period ensures a unidirectional spread of the action potential down a nerve fiber.

Question 13

In divergence:

Accepted Answer

A)  Many presynaptic neurons synapse with one postsynaptic cell. 
B)  Dendrites diverge from the cell body to contact many presynaptic neurons. 
C)  The action potential initiated in the axon diminishes as it spreads into the axon terminals. 
D)  An axon branches to synapse with many cells so that activity in one neuron influences the excitability of many other cells. 
E)  Many axons spread out from one cell body. 
A)  Many presynaptic neurons synapse with one postsynaptic cell. 
B)  Dendrites diverge from the cell body to contact many presynaptic neurons. 
C)  The action potential initiated in the axon diminishes as it spreads into the axon terminals. 
D)  An axon branches to synapse with many cells so that activity in one neuron influences the excitability of many other cells. 
E)  Many axons spread out from one cell body.

Question 14

An IPSP is

Accepted Answer

A)  produced by increased Na+ permeability and K+ permeability 
B)  produced by increased K+ permeability or increased Cl- permeability 
C)  a hyperpolarization of the presynaptic cell 
D)  produced by increased Na+ permeability and K+ permeability and a hyperpolarization of the presynaptic cell 
E)  produced by increased K+ permeability or increased Cl- permeability and a hyperpolarization of the presynaptic cell. 
A)  produced by increased Na+ permeability and K+ permeability 
B)  produced by increased K+ permeability or increased Cl- permeability 
C)  a hyperpolarization of the presynaptic cell 
D)  produced by increased Na+ permeability and K+ permeability and a hyperpolarization of the presynaptic cell 
E)  produced by increased K+ permeability or increased Cl- permeability and a hyperpolarization of the presynaptic cell.

Question 15

A given synapse may produce EPSPs at one time and IPSPs at another time.

Accepted Answer

A) True 
 B)False

Question 16

The diffusion of potassium ions reestablishes the resting membrane potential in a neuron immediately after it develops an action potential.

Accepted Answer

A) True 
 B)False

Question 17

Complete each of the following statments.
An increase in the size of the ____________________ of a nerve fiber, along with the amount of ____________________ around the fiber both increase its rate of conduction.

Accepted Answer

The answer of Complete each of the following statments.
An increase...

Question 18

What might happen on a postsynaptic neuron if, at the same time, it receives one stimulus at an excitatory synapse located close to the axon hillock but receives two stimuli at two different inhibitory synapses, both of which are far away from the axon hillock?

Accepted Answer

Since graded potentials diminish in inte

Question 19

Conduction by local current flow

Accepted Answer

A)  occurs in unmyelinated fibers 
B)  is faster than propagation of an action potential in myelinated fibers because myelin acts as an insulator to slow down the impulse 
C)  involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold 
D)  all of these 
E)  occurs in unmyelinated fibers and involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold 
A)  occurs in unmyelinated fibers 
B)  is faster than propagation of an action potential in myelinated fibers because myelin acts as an insulator to slow down the impulse 
C)  involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold 
D)  all of these 
E)  occurs in unmyelinated fibers and involves current flowing between active and adjacent inactive areas, thereby bringing the inactive areas to threshold

Question 20

If neuron Z is repeatedly stimulated very rapidly, what change would you expect in the postsynaptic neuron?

Accepted Answer

A)  several simultaneous action potentials 
B)  movement farther away from threshold 
C)  spatial summation of EPSPs 
D)  movement farther away from threshold and spatial summation of EPSPs 
E)  none of these 
A)  several simultaneous action potentials 
B)  movement farther away from threshold 
C)  spatial summation of EPSPs 
D)  movement farther away from threshold and spatial summation of EPSPs 
E)  none of these

Exam 4: Principles of Neural and Hormonal Communication

The membrane is more permeable to K+ than to Na+

Which statement about graded potentials is false?

What is responsible for development of the resting membrane potential?

A spike is another name for the axon of a neuron.

The refractory period prevents action potentials from spreading back over the part of the membrane where the impulse has just passed.

Oligodendrocytes are specialized to conduct electrical impulses to neurons.

Presynaptic inhibition is brought about when dendrites of a postsynaptic neuron alter the signals sent from an axon terminal of a presynaptic neuron.

Sequence the following events correctly. 1. Neurotransmitter diffuses across cleft. 2. Calcium induces exocytosis of neurotransmitter. 3. Permeability of postsynaptic membrane altered. 4. Ion channels open. 5. Neurotransmitter binds to receptor.

Complete each of the following statments. A plasma membrane is polarized if it separates particles with an opposite ____________________.

A single neuron may be presynaptic to one group of neurons and postsynaptic to another group of neurons.

Which statement is not accurate about the absolute refractory period?

In divergence:

An IPSP is

A given synapse may produce EPSPs at one time and IPSPs at another time.

The diffusion of potassium ions reestablishes the resting membrane potential in a neuron immediately after it develops an action potential.

Complete each of the following statments. An increase in the size of the ____________________ of a nerve fiber, along with the amount of ____________________ around the fiber both increase its rate of conduction.

What might happen on a postsynaptic neuron if, at the same time, it receives one stimulus at an excitatory synapse located close to the axon hillock but receives two stimuli at two different inhibitory synapses, both of which are far away from the axon hillock?

Conduction by local current flow

If neuron Z is repeatedly stimulated very rapidly, what change would you expect in the postsynaptic neuron?

Introduction to Physiology and Homeostasis

Cell Physiology

The Plasma Membrane and Membrane Potential

A--The Central Nervous System

B--The Central Nervous System

A--The Peripheral Nervous System: Afferent Division; Special Senses

B--The Peripheral Nervous System: Afferent Division; Special Senses

The Peripheral Nervous System: Efferent Division

A--Muscle Physiology

B--Muscle Physiology

A--Cardiac Physiology

B--Cardiac Physiology

The Blood Vessels and Blood Pressure

The Blood

Body Defenses

A--The Respiratory System

B--The Respiratory System

A--The Urinary System

B--The Urinary System

A--Fluid and Acid-Base Balance

B--Fluid and Acid-Base Balance

A--The Digestive System

B--The Digestive System

Energy Balance and Temperature Regulation

A--Principles of Endocrinology: the Central Endocrine Glands

B--Principles of Endocrinology: the Central Endocrine Glands

A--The Peripheral Endocrine Glands

B--The Peripheral Endocrine Glands

A--The Reproductive System

B--The Reproductive System

Filters

The membrane is more permeable to K⁺ than to Na⁺

Complete each of the following statments. An increase in the size of the of a nerve fiber, along with the amount of around the fiber both increase its rate of conduction.