Nervous System-Ion Channels, RMB, AP

Question 1

Define voltage

Answer 1

A measure of potential difference between two points (V or mV)

Question 2

Define current

Answer 2

Flow of electrical charge (ions) between two points

Question 3

Define resistance

Answer 3

Hindrance to charge flow

Question 4

Ohm’s law

Answer 4

Current (l)= voltage (V) / resistance (R)

Question 5

Two main types of ion channels

Answer 5

• Leakage (non-gated) channels

- Gated channels

Question 6

Three different types of gated ion channels

Answer 6

• Ligand gated (chemically-gated)
• Voltage-gated
• Mechanically-gated

Question 7

Ligand-gated (chemically gated) channel

Answer 7

Binds to a specific chemical

Question 8

Voltage-gated channel

Answer 8

Responds to changes in membrane potential

Question 9

Mechanically gated channels

Answer 9

Responds to physical deformation of sensory receptors

Question 10

Where are ions diffused when gated channels are open?

Answer 10

Along an electrochemical gradient

Question 11

How are ions diffused in chemical concentration gradients?

Answer 11

From higher concentration to lower concentration

Question 12

How are ions diffused in electrical gradient?

Answer 12

Toward opposite electrical charge

Question 13

What are the two factors that influence resting membrane potential?

Answer 13

• Differences in ionic composition across membrane

- Differences in plasma membrane permeability