Chapter 16 Neurophysiology Of Nerve Impulses Frog Subjects

Front 1

Excitabilty/Conductivity is the ability to transmit nerve impulses to other neurons

Back 1

Conductivity

Front 2

when a neuron is stimulated, the membrane becomes more permeable to Na+ ions, which diffuse into the cell and cause

Back 2

depolarization

Front 3

As an action potential progresses, the permeability to Na+ decreases, and the permeability to this ion increase

Back 3

K+

Front 4

The period of time when the neuron is totally insensitive to further stimulation and cannot generate another action potential is

Back 4

absolute refractory period

Front 5

what muscle and nerve will you need to isolate to study the physiology of nerve fibers?

Back 5

gastrocnemius and sciatic

Front 6

period of depolarization of the neuron membrane during which it cannot respond to a second stimulus

Back 6

absolute refractory period

Front 7

reversal of the resting potential due to an influx of sodium ions

Back 7

depolarization

Front 8

period during which potassium ions diffuse out of the neuron because of a change in membrane permeability

Back 8

repolarization

Front 9

period of repolarization when only a strong stimulus will elicit an action potential

Back 9

relative refractory period

Front 10

mechanism in which ATP is used to move sodium out of the cell and potassium into the cell; restores the resting membrane voltage and intracellular ionic concentrations

Back 10

sodium-potassium pump

Front 11

define the term depolarization

Back 11

when a neuron receives an excitatory stimulus the membrane becomes more permeable to sodium ions and Na+ diffuses down its electrochemical gradient. interior membrane becomes less negative.

Front 12

how does an action potential differ from simple depolarization?

Back 12

action potential only occurs only if it reaches the threshold. depolarization can happen at any time.

Front 13

would a substance that decreases membrane permeability to sodium increase or decrease the probability of generating an action potential? why?

Back 13

decrease membrane permeability is sodium, substance will decrease permeability through the membrane, no depolarization

Front 14

name the three types of stimuli that resulted in action potential generation in the sciatic nerve of the frog

Back 14

mechanical, thermal, chemical

Front 15

which of the stimuli resulted in the most effective nerve stimulation

Back 15

chemical

Front 16

what is the usual mode of stimulus transfer in neuron-to-neuron interactions?

Back 16

chemical

Front 17

since the action potentials themselves were not visualized with an oscilloscope during this initial set of experiments how did you recognize that impulses were being transmitted?

Back 17

muscle contraction

Front 18

how did the site of action of ether and tubocurarine differ?

Back 18

difference is ether acts on the nerve, tubocurarine blocks the muscle

Front 19

in the tubocurarine experiment, why was one of the frog's legs ligated?

Back 19

to keep tubocurarine from affecting the frog's other leg