Electrophysiology I

Question 0

A potential difference between the inside of the cell and the outside of the cell is known as what?

Answer 0

Membrane potential

Question 1

A chennelopathy during which an increase in serum potassium and subsequent membrane depolarization causes paralysis of skeletal muscle is known as what?

Answer 1

Hyperkalemic periodic paralysis

Question 2

Decreasing the membrane potential is known as what?

Answer 2

Depolarization

Question 3

Increasing the membrane potential is known as what?

Answer 3

Hyperpolarization

Question 4

Returning the membrane potential to normal is known as what?

Answer 4

Repolarization

Question 5

At rest the permeability of what ion is higher than that of other ions?

Answer 5

K+

Question 6

What establishes the concentration gradient of Na+ and K+?

Answer 6

Na+-K+ ATPase

Question 7

Membrane permeability is in excitable cells is determined by transmembrane proteins called what?

Answer 7

Ion channels

Question 8

What are the 3 important structural properties of ion channels?

Answer 8

Selectivity sensors, filters and gates

Question 9

What allow the ion channel to pass only one species of ion across a membrane, most important ions are Na+, K+, Cl-, Ca+, or non-selective among small ions?

Answer 9

Selectivity filters

Question 10

What can open to let a selected ion pass freely through a channel or close to inhibit passing?

Answer 10

Gates

Question 11

What are the two types of gates?

Answer 11

Activation gates - open on depolarization

Inactivation gates - close on depolarization

Question 12

What is the portion of the channel that determines weather the gate is open or closed?

Answer 12

Sensor

Question 13

What are the two types of sensors?

Answer 13

Voltage sensors - respond to transmembrane voltage

Ligand sensors - respond to extra cellular neurotransmitters or intracellular 2nd messengers

Question 14

What is the type of gate used in K+ induced hyperpolarization to maintain the resting potential?

Answer 14

Ungated

Question 15

What is the gate used in K+ induced hyperpolarization to terminate an action potential?

Answer 15

Voltage

Question 16

What is the gate used in Na+ induced depolarization to initiate an action potential?

Answer 16

Voltage

Question 17

What is the gate used in Ca2+ induced depolarization to increase the amount of Ca2+?

Answer 17

Voltage

Question 18

What is the gate used in Cl- induced hyperpolarization that makes an inhibitory synaptic potential?

Answer 18

Ligand

Question 19

What is the gate used in non selective ion induced depolarization that makes an excitatory synaptic potential?

Answer 19

Ligand

Question 20

What equation is useful in calculating equilibrium potential when there is only 1 permeant ion?

Answer 20

Nernst equation

Question 21

What equation is useful in establishing equilibrium potential with multiple permeable ions?

Answer 21

Goldmans equation

Question 22

Hyperkalemia has what effect on the membrane potential?

Answer 22

It lowers it causing a lower threshold for depolarization