Question 1

Complete each of the following statments.
Axon terminals possess ____________________ voltage-gated channels that when operational induce neurotransmitter release.

Accepted Answer

The answer of Complete each of the following statments.
Axon terminals...

Question 2

Use these figures to answer the corresponding questions.
The structure labeled "4" is
 
a.	part of a channel that allows Na+ ions to diffuse into the ECF
b.	the activation gate for a gated K+ channel
c.	the inactivation gate for a gated Na+ channel
d.	part of a second messenger system
e.	the activation gate for a gated K+ channel and part of a second messenger system

Accepted Answer

The answer of Use these figures to answer the corresponding...

Question 3

Permeability of which ion is affected by a positive feedback mechanism once threshold is reached?

Accepted Answer

A)   sodium
B)   potassium
C)   calcium
D)   chloride
E)   proteinF) A) and E)
G) None of the above

Question 4

An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter.

Accepted Answer

A) True 
 B)False

Question 5

The tyrosine-kinase pathway is activated in response to certain lipophilic hormones, whereas the second messenger pathway is activated in response to certain hydrophilic hormones.

Accepted Answer

A) True 
 B)False

Question 6

The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.

Accepted Answer

A) True 
 B)False

Question 7

Complete each of the following statments.
When EPSPs occurring simultaneously from two different presynaptic inputs add together or sum to bring the postsynaptic cell to threshold, it is called ____________________.

Accepted Answer

The answer of Complete each of the following statments.
When EPSPs...

Question 8

The nodes of Ranvier are Schwann cells or oligodendrocytes that wrap themselves "jelly roll fashion" around the axon.

Accepted Answer

A) True 
 B)False

Question 9

Neuron A is excitatory to neuron
B. Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.

Accepted Answer

The answer of Neuron A is excitatory to neuron
B. Describe...

Question 10

Use these figures to answer the corresponding questions.
Which number identifies the structure that is primarily responsible for the absolute refractory period during an action potential?
 
a.	1
b.	2
c.	3-5
d.	4
e.	No number identifies this structure.

Accepted Answer

The answer of Use these figures to answer the corresponding...

Question 11

Which statement about a graded potential is false?

Accepted Answer

A)   It can be a depolarization.
B)   It can be a hyperpolarization.
C)   It can be summated.
D)   It has a refractory period.
E)   It occurs in a specialized area of the membrane.F) A) and D)
G) A) and C)

Question 12

The falling phase of the action potential is due to

Accepted Answer

A)   calcium equilibrium
B)   potassium efflux
C)   potassium influx
D)   sodium efflux
E)   sodium influxF) A) and E)
G) C) and D)

Question 13

When an excitatory neurotransmitter binds to a postsynaptic neuron

Accepted Answer

A)   Voltage-gated Na+ channels open.
B)   Voltage-gated K+ channels open.
C)   Chemically-gated Na+ channels open.
D)   Voltage-gated Cl- channels open.
E)   Chemically-gated Cl- channels open.F) D) and E)
G) C) and D)

Question 14

At an excitatory synapse, an action potential in the presynaptic neuron increases the

Accepted Answer

A)   membrane potential of the postsynaptic cell membrane
B)   permeability of the postsynaptic cell to both Na+
C)   permeability of the postsynaptic cell to Cl-
D)   all of these
E)   membrane potential of the postsynaptic cell membrane and permeability of the postsynaptic cell to both Na+F) None of the above
G) C) and D)

Question 15

When the membrane potential is +15 mV, that portion of the membrane

Accepted Answer

A)   is in the normal resting state
B)   has a more positive outside border
C)   is more permeable to Ca2+ than normal
D)   is in the after hyperpolarization phase of an action potential
E)   has a more positive outside border and is more permeable to Ca2+ than normalF) A) and D)
G) D) and E)

Question 16

Complete each of the following statments.
When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________.

Accepted Answer

The answer of Complete each of the following statments.
When EPSPs...

Question 17

Neuropeptides are mainly neuromodulators that function as second messengers in cells that respond to hydrophilic hormones.

Accepted Answer

A) True 
 B)False

Question 18

Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.

Accepted Answer

A) True 
 B)False

Question 19

The refractory period limits the frequency of action potentials.

Accepted Answer

A) True 
 B)False

Question 20

The absolute refractory period

Accepted Answer

A)   prevents action potentials from spreading forward and backward
B)   refers to a period when the membrane cannot undergo another action potential
C)   is the time when channels opened during the action potential have not been restored to their "closed but capable of opening" conformation
D)   places an upper limit on the frequency with which a neuron can conduct action potentials
E)   refers to a period when the membrane cannot undergo another action potential and places an upper limit on the frequency with which a neuron can conduct action potentialsF) A) and E)
G) A) and D)

Exam 4: Principles of Neural and Hormonal Communication

Correct Answer
verified

Neuron A is excitatory to neuron B. Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.

Correct Answer
verified

An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter.

Correct Answer
verified

The tyrosine-kinase pathway is activated in response to certain lipophilic hormones, whereas the second messenger pathway is activated in response to certain hydrophilic hormones.

Correct Answer
verified

The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.

Correct Answer
verified

Which statement about a graded potential is false?

Correct Answer
verified

The nodes of Ranvier are Schwann cells or oligodendrocytes that wrap themselves "jelly roll fashion" around the axon.

Correct Answer
verified

The falling phase of the action potential is due to

Correct Answer
verified

Complete each of the following statments. When EPSPs occurring simultaneously from two different presynaptic inputs add together or sum to bring the postsynaptic cell to threshold, it is called ____________________.

Correct Answer
verified

When an excitatory neurotransmitter binds to a postsynaptic neuron

Correct Answer
verified

At an excitatory synapse, an action potential in the presynaptic neuron increases the

Correct Answer
verified

Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.

Correct Answer
verified

Complete each of the following statments. When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________.

Correct Answer
verified

Neuropeptides are mainly neuromodulators that function as second messengers in cells that respond to hydrophilic hormones.

Correct Answer
verified

Complete each of the following statments. Axon terminals possess ____________________ voltage-gated channels that when operational induce neurotransmitter release.

Correct Answer
verified

The refractory period limits the frequency of action potentials.

Correct Answer
verified

The absolute refractory period

Correct Answer
verified

When the membrane potential is +15 mV, that portion of the membrane

Correct Answer
verified

Permeability of which ion is affected by a positive feedback mechanism once threshold is reached?

Correct Answer
verified

Correct Answer
verified

Exam 4: Principles of Neural and Hormonal Communication

Use these figures to answer the corresponding questions. Which number identifies the structure that is primarily responsible for the absolute refractory period during an action potential? a. 1 b. 2 c. 3-5 d. 4 e. No number identifies this structure.

Correct AnswerverifiedShow Answer

Neuron A is excitatory to neuron B. Describe three ways that the nervous system might prevent neuron B from experiencing an action potential.

Correct AnswerverifiedShow Answer

An unmyelinated fiber with a large diameter can conduct action potentials more rapidly than an unmyelinated fiber with a smaller diameter.

Correct AnswerverifiedShow Answer

The tyrosine-kinase pathway is activated in response to certain lipophilic hormones, whereas the second messenger pathway is activated in response to certain hydrophilic hormones.

Correct AnswerverifiedShow Answer

The myelin on a myelinated fiber in the peripheral nervous system is part of Schwann cells wrapped around the axon.

Correct AnswerverifiedShow Answer

Which statement about a graded potential is false?

Correct AnswerverifiedShow Answer

The nodes of Ranvier are Schwann cells or oligodendrocytes that wrap themselves "jelly roll fashion" around the axon.

Correct AnswerverifiedShow Answer

The falling phase of the action potential is due to

Correct AnswerverifiedShow Answer

Complete each of the following statments. When EPSPs occurring simultaneously from two different presynaptic inputs add together or sum to bring the postsynaptic cell to threshold, it is called ____________________.

Correct AnswerverifiedShow Answer

When an excitatory neurotransmitter binds to a postsynaptic neuron

Correct AnswerverifiedShow Answer

At an excitatory synapse, an action potential in the presynaptic neuron increases the

Correct AnswerverifiedShow Answer

Divergence refers to the neuronal arrangement wherein the dendrites diverge to synapse with as many presynaptic inputs as possible.

Correct AnswerverifiedShow Answer

Complete each of the following statments. When EPSPs originating from a single presynaptic input occur so close together in time that they add together or sum, thereby bringing the postsynaptic cell to threshold, it is called ____________________.

Correct AnswerverifiedShow Answer

Neuropeptides are mainly neuromodulators that function as second messengers in cells that respond to hydrophilic hormones.

Correct AnswerverifiedShow Answer

Complete each of the following statments. Axon terminals possess ____________________ voltage-gated channels that when operational induce neurotransmitter release.

Correct AnswerverifiedShow Answer

The refractory period limits the frequency of action potentials.

Correct AnswerverifiedShow Answer

The absolute refractory period

Correct AnswerverifiedShow Answer

When the membrane potential is +15 mV, that portion of the membrane

Correct AnswerverifiedShow Answer

Permeability of which ion is affected by a positive feedback mechanism once threshold is reached?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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