Question 1

The all-or-none principle states that

Accepted Answer

A)  all stimuli will produce identical action potentials. 
B)  all stimuli great enough to bring the membrane to threshold will produce action potentials of identical magnitude. 
C)  the greater the magnitude of the stimuli, the greater the intensity of the action potential. 
D)  only sensory stimuli can activate action potentials. 
E)  only motor stimuli can activate action potentials. 
A)  all stimuli will produce identical action potentials. 
B)  all stimuli great enough to bring the membrane to threshold will produce action potentials of identical magnitude. 
C)  the greater the magnitude of the stimuli, the greater the intensity of the action potential. 
D)  only sensory stimuli can activate action potentials. 
E)  only motor stimuli can activate action potentials.

Question 2

"A refractory period occurs following all types of potentials." Is this statement True or False? What structures are actually refractory? Why or why not?

Accepted Answer

A) True 
 B)False

Question 3

Draw graphs showing the effect on action potentials in a cell following effective doses of each of the listed neurotoxins.Assume that the cell is normally brought to threshold by an electrical stimulus applied to it, so that any abnormality is due to the toxin.Precise values for voltage and duration are not important, just a general trend in how the action potential may be different from normal.
1.puffer fish poison (blocks voltage-gated sodium channel activation)
2.tetraethylammonium (blocks voltage-gated potassium channels)
3.ouabain (blocks sodium-potassium pumps)
4.sea anemone toxin (blocks voltage-gated sodium channel inactivation)

Accepted Answer

1.no action potential; membrane potentia

Question 4

Interneurons are found

Accepted Answer

A)  only in the brain. 
B)  only in the spinal cord. 
C)  only in the CNS. 
D)  throughout the nervous system. 
E)  only in spinal nerves. 
A)  only in the brain. 
B)  only in the spinal cord. 
C)  only in the CNS. 
D)  throughout the nervous system. 
E)  only in spinal nerves.

Question 5

Conduction occurs along an axon because

Accepted Answer

A)  outflow of K⁺ triggers the adjacent channels to open. 
B)  inflow of Na⁺ triggers the adjacent channels to open. 
C)  once Na⁺ enters the cell, the entire membrane depolarizes simultaneously. 
D)  axonal transport "walks" voltage changes along the membrane. 
A)  outflow of K⁺ triggers the adjacent channels to open. 
B)  inflow of Na⁺ triggers the adjacent channels to open. 
C)  once Na⁺ enters the cell, the entire membrane depolarizes simultaneously. 
D)  axonal transport "walks" voltage changes along the membrane.

Question 6

All of the following must occur before a second action potential can begin, EXCEPT

Accepted Answer

A)  the Na⁺ and K⁺ ions that moved in/out of the cell must move back to their original compartments. 
B)  the Na⁺ inactivation gate must open and the Na⁺ activation gate must close. 
C)  the absolute refractory period must occur. 
D)  the Na⁺ and K⁺ ions that moved in/out of the cell must move back to their original compartments; the Na⁺ inactivation gate must open; and the Na⁺ activation gate must close. 
E)  None of the answers are correct. 
A)  the Na⁺ and K⁺ ions that moved in/out of the cell must move back to their original compartments. 
B)  the Na⁺ inactivation gate must open and the Na⁺ activation gate must close. 
C)  the absolute refractory period must occur. 
D)  the Na⁺ and K⁺ ions that moved in/out of the cell must move back to their original compartments; the Na⁺ inactivation gate must open; and the Na⁺ activation gate must close. 
E)  None of the answers are correct.

Question 7

Explain the roles that the AMPA and NMDA receptors play in long-term potentiation.

Accepted Answer

Both AMPA and NMDA receptors are located

Question 8

Learning and memory are thought to be due to a synaptic phenomenon known as

Accepted Answer

A)  inhibition. 
B)  excitation. 
C)  modulation. 
D)  facilitation. 
E)  long-term potentiation. 
A)  inhibition. 
B)  excitation. 
C)  modulation. 
D)  facilitation. 
E)  long-term potentiation.

Question 9

Create diagrams (of the cells)and graphs (of the potentials)to illustrate the two different situations described below in a multipolar neuron with a threshold voltage of 15 mV above resting potential.In each, indicate decrement of graded potentials (by drawing the same GP at different points as it spreads along the neuron), as well as summation.
Situation 1: There are three simultaneously active synapses on the multipolar neuron, two producing EPSPs and one an IPSP.At least one of the EPSPs is larger than 15 mV at the synapse.The neuron does NOT generate an action potential.
Situation 2: There are two simultaneously active synapses, one producing an EPSP and the other an IPSP.The neuron generates an action potential.

Accepted Answer

(Note to instructor: It is best to have

Question 10

An excitatory postsynaptic potential (EPSP)

Accepted Answer

A)  depolarizes a neuron, decreasing the likelihood of an action potential. 
B)  hyperpolarizes a neuron, decreasing the likelihood of an action potential. 
C)  depolarizes a neuron, increasing the likelihood of an action potential. 
D)  hyperpolarizes a neuron, increasing the likelihood of an action potential. 
A)  depolarizes a neuron, decreasing the likelihood of an action potential. 
B)  hyperpolarizes a neuron, decreasing the likelihood of an action potential. 
C)  depolarizes a neuron, increasing the likelihood of an action potential. 
D)  hyperpolarizes a neuron, increasing the likelihood of an action potential.

Question 11

Draw graphs showing the effects of hypokalemia and hyperkalemia on action potential production.Don't worry about exact millivolt values - the point is to show that you understand the effects of these conditions relative to normal.

Accepted Answer

Graphs should resemb

Question 12

The sum of all of the electrical and chemical forces active across the membrane is known as the ________.

Accepted Answer

The answer of The sum of all of the electrical...

Question 13

Match the part of the neuron to its description (answers may be used more than once).
-location of voltage-gated ion channels

Accepted Answer

A) dendrites 
B) axon 
C) cell body 
A) dendrites 
B) axon 
C) cell body

Question 14

The site of information integration in the nervous system is the

Accepted Answer

A)  chemical synapse. 
B)  electrical synapse. 
C)  trigger zone. 
D)  dendritic membrane. 
E)  axon terminal. 
A)  chemical synapse. 
B)  electrical synapse. 
C)  trigger zone. 
D)  dendritic membrane. 
E)  axon terminal.

Question 15

The time during which an excitable membrane cannot respond to further stimulation regardless of the stimulus strength is the ________.

Accepted Answer

absolute r

Question 16

The multiple thin, branched structures on a neuron whose main function is to receive incoming signals are the

Accepted Answer

A)  cell bodies. 
B)  axons. 
C)  dendrites. 
D)  somata. 
E)  None of the answers are correct. 
A)  cell bodies. 
B)  axons. 
C)  dendrites. 
D)  somata. 
E)  None of the answers are correct.

Question 17

For ________ to occur, a second potential must arrive before a previous one has been completed.

Accepted Answer

The answer of For ________ to occur, a second potential...

Question 18

These glial cells act as scavengers.

Accepted Answer

A)  Schwann cells 
B)  astrocytes 
C)  microglia 
D)  oligodendrocytes 
E)  ependymal cells 
A)  Schwann cells 
B)  astrocytes 
C)  microglia 
D)  oligodendrocytes 
E)  ependymal cells

Question 19

The point during an action potential when the inside of the cell has become more positive than the outside is known as the

Accepted Answer

A)  depolarization. 
B)  rising phase. 
C)  falling phase. 
D)  overshoot. 
E)  peak. 
A)  depolarization. 
B)  rising phase. 
C)  falling phase. 
D)  overshoot. 
E)  peak.

Question 20

Match the term with its description (answers may be used more than once).
-cells that myelinate several axons

Accepted Answer

A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia 
A) ependymal cells 
B) astrocytes 
C) satellite cells 
D) Schwann cells 
E) oligodendrocytes
F)microglia

Exam 8: Neurons: Cellular and Network Properties

The all-or-none principle states that

"A refractory period occurs following all types of potentials." Is this statement True or False? What structures are actually refractory? Why or why not?

Interneurons are found

Conduction occurs along an axon because

All of the following must occur before a second action potential can begin, EXCEPT

Explain the roles that the AMPA and NMDA receptors play in long-term potentiation.

Learning and memory are thought to be due to a synaptic phenomenon known as

An excitatory postsynaptic potential (EPSP)

Draw graphs showing the effects of hypokalemia and hyperkalemia on action potential production.Don't worry about exact millivolt values - the point is to show that you understand the effects of these conditions relative to normal.

The sum of all of the electrical and chemical forces active across the membrane is known as the ________.

Match the part of the neuron to its description (answers may be used more than once). -location of voltage-gated ion channels

The site of information integration in the nervous system is the

The time during which an excitable membrane cannot respond to further stimulation regardless of the stimulus strength is the ________.

The multiple thin, branched structures on a neuron whose main function is to receive incoming signals are the

For ________ to occur, a second potential must arrive before a previous one has been completed.

These glial cells act as scavengers.

The point during an action potential when the inside of the cell has become more positive than the outside is known as the

Match the term with its description (answers may be used more than once). -cells that myelinate several axons

Introduction to Physiology

Molecular Interactions

Compartmentation: Cells and Tissues

Energy and Cellular Metabolism

Membrane Dynamics

Communication, Integration, and Homeostasis

Introduction to the Endocrine System

The Central Nervous System

Sensory Physiology

Efferent Division: Autonomic and Somatic Motor Control

Muscles

Integrative Physiology I: Control of Body Movement

Cardiovascular Physiology

Blood Flow and the Control of Blood Pressure

Blood

Mechanics of Breathing

Gas Exchange and Transport

The Kidneys

Integrative Physiology II: Fluid and Electrolyte Balance

The Digestive System

Metabolism and Energy Balance

Endocrine Control of Growth and Metabolism

The Immune System

Integrative Physiology III: Exercise

Reproduction and Development

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