Stimulated Excitable Cells

Question 1

Ion channels react to stimuli, increasing or decreasing ionic flux

Answer 1

Signal transduction

Question 2

Receptor and postsynaptic potentials grow smaller with distance from initiation site

Answer 2

Decremental potential

Question 3

Distance over which a electrical potential decays

Answer 3

Length constant

Question 4

What does greater length constant indicate

Answer 4

Lesser decrement

Lower intracellular resistance

Greater membrane resistance

Question 5

Which area of the axon is populated by voltage-gated sodium channels

Answer 5

Impulse Initiation zone

Question 6

Ionic basis of action potentials

Answer 6

Na+ channels open then inactivate

K+ channels wait, open and inactive slowly

Question 7

Inactivation ball plugs channel

Answer 7

Channel remains inactive until voltage resets (absolute or relative refractory)

Question 8

How is the distribution of voltage-gated channels on unmyelinted axons

Answer 8

Sparse distribution

Question 9

How is voltage-gated distribution on myelinated axons

Answer 9

Dense (nodes of Ranvier)

Question 10

High intracellular resistance

Answer 10

Short length constant

Question 11

Low intracellular resistance

Answer 11

Long length constant

Question 12

Drug that blocks voltage-gated Na+ channels

Answer 12

Lidocaine