Vertebrate Physiology Study Guide Test 2

Front 1

Depolarization of a Neuron to threshold stimulates?

A) Opening of Sodium channels

B) Delaying closing of sodium channels

C) Delayed opening of potassium channels

D) All of the above

Back 1

All of the above

Front 2

Neurotransmitters are released most commonly from the?

Back 2

Axon terminals

Front 3

If a cation is equally distributed across the cell membrane (that is, it's concentration inside the cell equals the concentration outside the cell). What happens at -70mV, 30mV and equilibrium?

Back 3

At -70mV the chemical force on the ion is zero, the electrical force on the ion acts to move it into the cell.

At 30mV the chemical force on the ion is zero.

At equilibrium potential the ion is zero.

Front 4

The depolarization phase of an action potential is caused by the?

Back 4

Opening of sodium channels

Front 5

During the relative refractory period, a second action potential

Back 5

Can be elicited by a suprathreshold stimulus.

Front 6

Nerves are found?

Back 6

In the peripheral nervous system

Front 7

If the membrane potential of a neuron becomes more negative than it was at rest, then the neuron is________. In this state, the neuron is ________ excitable.

Back 7

Hyperpolarized; Less

Front 8

Oubain is a poison that blocks potassium/ sodium pump. if this pump is blocked, then the concentration of potassium inside the cell would?

Back 8

Decrease

Front 9

If potassium concentrations in the extracellular fluid of the brain increased, activity in the brain would?

Back 9

Increase

Front 10

Which of the fallowing neurons are part of the peripheral nervous system

A) Motor neurons innervating skeletal muscles

B) Parasympathetic Neurons

C) Sympathetic Neurons

D) All of the above

Back 10

All of the above

Front 11

Which of the following axons exhibits the greatest conduction velocity?

Back 11

A myelinated axon with a diameter 20um

Front 12

Which of the following best describes the status of sodium channels at the resting membrane potential?

Back 12

Activation gates are closed and inactivation gates are open.

Front 13

Which of the following is NOT part of the efferent division of the nervous system

A) parasympathetic Nervous system

B) Sympathetic Nervous system

C) Motor Neurons

D) Sensory receptors

Back 13

Sensory receptors

Front 14

Which of the following statements about graded potentials is false?

A) The magnitude varies with the strength of stimulus

B) Some are hyperpolarizations; others are depolarizations

C) They are produced at ligand-gated ion channels

D) They can sum over space and time.

E) They are limited in duration by the refractory period.

Back 14

They are limited in duration by the refractory period.

Front 15

Of the following ions, which is (are) located in greater concentration inside the cell?

A) sodium only

B) potassium only

C) chloride only

D) sodium and potassium

e) potassium and chloride

Back 15

potassium only

Front 16

What are the subdivisions of the peripheral nervous system?

Back 16

Afferent and Efferent

Front 17

Information from the periphery is brought to the central nervous system by________ pathways.

Back 17

Afferent

Front 18

Which type of cell is more abundant in the nervous system?

A) Glial Cells

B) Nerurons

Back 18

Glial Cells

Front 19

Voltage-gated calcium channels are located in which region(s) of a neuron?

Back 19

Axon Terminals

Front 20

(schwann cells/oligodendrocytes) form myelin in the peripheral nervous system, and (schwann cells/oligodendrocytes)from myelin in the central nervous system .

Back 20

Schwann cells, Oligodendrocytes

Front 21

myelin _______ conduction velocity in axons

Back 21

Increases

Front 22

if an anion is present in greater concentration outside the cell compared to inside the cell, would the equilibrium potential for that anion be positive, negative, or zero?

Back 22

Negative

Front 23

which ion is closer to equilibrium at the resting membrane potential of -70 mV - sodium or potassium ?

Back 23

Potassium

Front 24

in the peripheral nervous system, cell bodies of afferent neurons are located in ____.

Back 24

Ganglion

Front 25

the electrochemical force for potassium ions when the membrane potential is at the peak of an action potential is (greater than/less) the electrochemical force for potassium ions when the membrane potential is at rest.

Back 25

Greater Than

Front 26

both sodium and potassium channels have inactivation gates that close shortly after the activation gates open. (true/ False)

Back 26

False

Front 27

when sodium inactivation gates are closed, a second action potential is impossible. (true/false)

Back 27

True

Front 28

in myelinated axons, action potentials are propagated by _____ conduction.

Back 28

Saltatory

Front 29

The Sodium/Potassium pump causes the repolarization phase of an action potential. (true/false)

Back 29

False