Question 1

Neurons are capable of detecting and transducing incoming signals such as

Accepted Answer

A) light. 
B) pressure. 
C) environmental chemicals. 
D) all of the above

Question 2

Briefly state the importance of voltage-gated Na⁺ channels.Explain why the tetrodotoxin (TTX)found in California newts (Taricha torosa)does not kill the newts.Would you expect garter snakes (Thamnopis sirtalis),which are predators of newts,to die once they consume the toxic newts?

Accepted Answer

The answer of Briefly state the importance of voltage-gated Na⁺...

Question 3

If the sodium-potassium pump was inhibited by a drug,such as digitalis,what would happen to the membrane potential of the cell?

Accepted Answer

A) The membrane potential would slowly decrease. 
B) There would be an instant loss of membrane potential. 
C) There would be an instant decrease followed by an increase in membrane potential. 
D) The leak channels would be disrupted.

Question 4

What mechanism causes the voltage-gated Na⁺ channels to close during an action potential?

Accepted Answer

A) The activation gate is voltage sensitive and closes close to the equilibrium potential for Na⁺. 
B) The activation gate is sensitive to K⁺ and closes when its intracellular concentrations drop. 
C) The inactivation gate has a time-dependent closure. 
D) The inactivation gate is voltage sensitive and closes close to the equilibrium potential for Na⁺.

Question 5

Which of the following statements correctly describes the nodes of Ranvier?

Accepted Answer

A) They are areas of myelin-covered axonal membrane. 
B) They are surrounded by lipid-rich Schwann cells. 
C) They are often referred to as internodes of the axons. 
D) They contain a high density of voltage-gated channels.

Question 6

A high speed of conduction along axons is very important for the survival of organisms,particularly when quicker response times allow escape from a predator.Many factors affect speed of conduction,including temperature,myelination,and the diameter of the axon.Discuss how myelination and diameter affect the cable properties of a neuron and affect conduction speeds.

Accepted Answer

The answer of A high speed of conduction along axons...

Question 7

All the choices below are examples of glial cells,but which one is NOT associated with the central nervous system?

Accepted Answer

A) microglia 
B) astrocytes 
C) schwann cells 
D) oligodendrocytes

Question 8

When a graded potential arrives at the axon hillock before an earlier graded potential has died out,the two potentials can be added in a process known as __________ __________.

Accepted Answer

The answer of When a graded potential arrives at the...

Question 9

__________ neurons have many dendrites,but only one axon.

Accepted Answer

A) Multipolar 
B) Bipolar 
C) Unipolar 
D) Pseudo-unipolar

Question 10

What is the correct relationship between graded potentials and action potentials?

Accepted Answer

A) Graded potentials are used to generate action potentials. 
B) Action potentials are used to generate graded potentials. 
C) Graded potentials and action potentials are two terms for the same phenomenon. 
D) All graded potentials increase the likelihood of an action potential.

Question 11

Neurotransmitter is packaged in vesicles that are released in response to an action potential.This leads to a "steplike" increase in the amount of neurotransmitter being released (one step for each vesicle),termed __________.

Accepted Answer

The answer of Neurotransmitter is packaged in vesicles that are...

Question 12

Neurotransmitters are synthesized in the cell body,then transported in vesicles to the axon terminals using __________.

Accepted Answer

The answer of Neurotransmitters are synthesized in the cell body,then...

Question 13

What role does Ca²⁺ play in synaptic transmission?

Accepted Answer

A) Ca²⁺ is released into the synapse,transmitting a signal to the postsynaptic cell. 
B) Ca²⁺ causes the release of vesicles from the readily releasable pool. 
C) Ca²⁺ causes vesicles to move from the storage pool to docking proteins. 
D) both B and C

Question 14

The area of the axon covered with myelin and found between the nodes of Ranvier is known as an __________.

Accepted Answer

The answer of The area of the axon covered with...

Question 15

What is the benefit of using action potentials for conductance of electrical signals,rather than simply using electrotonic spread?

Accepted Answer

A) Action potentials have a greater speed. 
B) Action potentials can vary in amplitude to convey more information. 
C) Action potentials can travel over longer distances. 
D) both A and C

Question 16

A motor neuron is an example of a type of

Accepted Answer

A) afferent neuron. 
B) efferent neuron. 
C) interneuron. 
D) sensory neuron.

Question 17

__________,or afferent neurons,are capable of sending information about the environment (internal and external)to the central nervous system.

Accepted Answer

The answer of __________,or afferent neurons,are capable of sending information...

Question 18

Conduction of action potentials along an axon is termed saltatory conduction because the action potential

Accepted Answer

A) is dependent on the ions Na⁺ and K⁺,portions of salts. 
B) appears to leap or jump from node to node. 
C) is named after Johan Saltare,who first discovered it. 
D) moves very rapidly down the axon.

Question 19

When a cell __________,the charge difference between the intracellular and extracellular fluids decreases.

Accepted Answer

The answer of When a cell __________,the charge difference between...

Question 20

Which of the following is a true difference between electrical and chemical synapses?

Accepted Answer

A) Electrical synapses are found in the central nervous system. 
B) Electrical synapses are the most common type of synapse. 
C) Electrical synapses typically send information in one direction (presynaptic cell to postsynaptic cell). 
D) Electrical synapses are much faster.

Exam 5: Neuron Structure and Function