Question 1

One "strong" stimulus can cause more than one action potential, but a "weak" stimulus may or may not generate an action potential.

Accepted Answer

A) True 
 B)False

Question 2

Cocaine blocks the binding of dopamine at postsynaptic membranes.

Accepted Answer

A) True 
 B)False

Question 3

The relative refractory period occurs after the action potential is complete because of the

Accepted Answer

A)  lingering inactivation of the voltage-gated Na+ channels 
B)  slowness of the voltage-gated K+ channels 
C)  action of the sodium-potassium pumps 
D)  lingering inactivation of the voltage-gated Na+ channels and slowness of the voltage-gated K+ channels 
E)  slowness of the voltage-gated K+ channels and action of the sodium-potassium pumps 
A)  lingering inactivation of the voltage-gated Na+ channels 
B)  slowness of the voltage-gated K+ channels 
C)  action of the sodium-potassium pumps 
D)  lingering inactivation of the voltage-gated Na+ channels and slowness of the voltage-gated K+ channels 
E)  slowness of the voltage-gated K+ channels and action of the sodium-potassium pumps

Question 4

Which term best describes an excitable cell when a resting membrane potential is present?

Accepted Answer

A)  polarized 
B)  depolarized 
C)  hyperpolarized 
D)  repolarized 
E)  nonpolarized 
A)  polarized 
B)  depolarized 
C)  hyperpolarized 
D)  repolarized 
E)  nonpolarized

Question 5

A threshold potential is

Accepted Answer

A)  the potential achieved when two opposing forces acting upon an ion (concentration and electrical gradients) achieve a state of equilibrium 
B)  the peak potential achieved during an action potential 
C)  the point at which there is an explosive increase in Na+ or Ca2+ permeability 
D)  the potential at which K+ permeability increases 
E)  always a positive potential 
A)  the potential achieved when two opposing forces acting upon an ion (concentration and electrical gradients) achieve a state of equilibrium 
B)  the peak potential achieved during an action potential 
C)  the point at which there is an explosive increase in Na+ or Ca2+ permeability 
D)  the potential at which K+ permeability increases 
E)  always a positive potential

Question 6

In convergence:

Accepted Answer

A)  Many presynaptic cells can synapse with a single postsynaptic cell. 
B)  An axon branches so that the activity in one neuron influences many other cells. 
C)  Many dendrites converge on the cell body. 
D)  All of these. 
E)  None of these. 
A)  Many presynaptic cells can synapse with a single postsynaptic cell. 
B)  An axon branches so that the activity in one neuron influences many other cells. 
C)  Many dendrites converge on the cell body. 
D)  All of these. 
E)  None of these.

Question 7

Myelinated fibers throughout the nervous system can regenerate when cut, but unmyelinated fibers cannot regenerate.

Accepted Answer

A) True 
 B)False

Question 8

What are four ways in which drugs might influence the nervous system at the neuronal level?

Accepted Answer

A drug or disease agent might:(1) alter

Question 9

During the resting potential, the membrane is more permeable to potassium ions than to sodium ions.

Accepted Answer

A) True 
 B)False

Question 10

Common second messengers include cAMP, acetylcholine, and calcium ions.

Accepted Answer

A) True 
 B)False

Question 11

Along a neuron, an action potential normally travels from the dendrites to the cell body to the axon.

Accepted Answer

A) True 
 B)False

Question 12

Complete each of the following statments.
An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.

Accepted Answer

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

Question 13

Because of the presence of both activation and inactivation gates, voltage-gated Na+ channels can

Accepted Answer

A)  be closed but capable of opening 
B)  be activated 
C)  be closed and not capable of opening 
D)  all of these 
E)  none of these 
A)  be closed but capable of opening 
B)  be activated 
C)  be closed and not capable of opening 
D)  all of these 
E)  none of these

Question 14

Complete each of the following statments.
____________________ is the hindrance to electrical charge movement.

Accepted Answer

The answer of Complete each of the following statments.
____________________ is...

Question 15

Neuromodulators

Accepted Answer

A)  bind to receptors at nonsynaptic sites 
B)  do not contribute directly to EPSPs 
C)  do not contribute directly to IPSPs 
D)  may influence neurotransmitter production 
E)  all of these 
A)  bind to receptors at nonsynaptic sites 
B)  do not contribute directly to EPSPs 
C)  do not contribute directly to IPSPs 
D)  may influence neurotransmitter production 
E)  all of these

Question 16

The time following an action potential during which a membrane cannot respond to another stimulus, regardless of its strength, is called the relative refractory period.

Accepted Answer

A) True 
 B)False

Question 17

A lipophilic chemical messenger uses a second messenger system to alter the activity of a target cell.

Accepted Answer

A) True 
 B)False

Question 18

Increased permeability of the postsynaptic cell to Cl- lessens the likelihood that the postsynaptic cell will undergo an action potential.

Accepted Answer

A) True 
 B)False

Question 19

Apoptosis refers to the uncontrolled, accidental death of useful cells that have been severely injured.

Accepted Answer

A) True 
 B)False

Question 20

Complete each of the following statments.
The ____________________ or ____________________ of a neuron is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.

Accepted Answer

The answer of Complete each of the following statments.
The ____________________...

Exam 4: Principles of Neural and Hormonal Communication

One "strong" stimulus can cause more than one action potential, but a "weak" stimulus may or may not generate an action potential.

Cocaine blocks the binding of dopamine at postsynaptic membranes.

The relative refractory period occurs after the action potential is complete because of the

Which term best describes an excitable cell when a resting membrane potential is present?

A threshold potential is

In convergence:

Myelinated fibers throughout the nervous system can regenerate when cut, but unmyelinated fibers cannot regenerate.

What are four ways in which drugs might influence the nervous system at the neuronal level?

During the resting potential, the membrane is more permeable to potassium ions than to sodium ions.

Common second messengers include cAMP, acetylcholine, and calcium ions.

Along a neuron, an action potential normally travels from the dendrites to the cell body to the axon.

Complete each of the following statments. An action potential in a presynaptic neuron induces opening of voltage-gated ____________________ channels in the synaptic knob, which triggers exocytosis of synaptic vesicles.

Because of the presence of both activation and inactivation gates, voltage-gated Na+ channels can

Complete each of the following statments. ____________________ is the hindrance to electrical charge movement.

Neuromodulators

The time following an action potential during which a membrane cannot respond to another stimulus, regardless of its strength, is called the relative refractory period.

A lipophilic chemical messenger uses a second messenger system to alter the activity of a target cell.

Increased permeability of the postsynaptic cell to Cl- lessens the likelihood that the postsynaptic cell will undergo an action potential.

Apoptosis refers to the uncontrolled, accidental death of useful cells that have been severely injured.

Complete each of the following statments. The ____________________ or ____________________ of a neuron is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.

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

Because of the presence of both activation and inactivation gates, voltage-gated Na⁺ channels can

Increased permeability of the postsynaptic cell to Cl^- lessens the likelihood that the postsynaptic cell will undergo an action potential.

Complete each of the following statments. The or of a neuron is a single, elongated tubular process that conducts action potentials away from the cell body and eventually terminates at other cells.