Physio : Action Potential

Question 1

Rhabdomyolysis, hemolysis, tumor lysis will affect the potassium levels in the ECF. How?

Answer 1

Elevated K levels in the ECF. Will cause influx of K into the cell and depolarize it. Can cause arrhythmia

Question 2

Occurs when the membrane potential becomes more negative

Answer 2

Hyperpolarization

Question 3

Occurs when the membrane potential become less negative or even positive

Answer 3

Depolarization

Question 4

Resting membrane potential is mainly based on

Answer 4

Potassium

Question 5

High potassium on ECG

Answer 5

Peaked t waves

Question 6

Low potassium on ecg

Answer 6

U waves

Question 7

Potassium problems causes cardiac problems.

Sodium causes _____ problems.

Answer 7

CNS

no conductance problem

Question 8

Hypercalcemia would cause

Answer 8

Flaccid paralysis of skeletal muscle

Stabilizes membranes

Question 9

Hypocalcemia causes

Answer 9

Spasms

Destabilizes membranes leading to spontaneous action potential

Question 10

Sodium potassium pump is electrogenic…flow is

Answer 10

3 na out,

2 k in

Question 11

Voltage gated na channels are blocked by

Answer 11

Tetrodotoxin

Question 12

Mechanism of depolarization

Answer 12

Na goes inside the cell

Question 13

Mechanism of repolarization

Answer 13

Na channels close

K channels open (K out)

Question 14

Mechanism of hyperpolarization

Answer 14

K channels stay open, k cont to go out

Question 15

The action potential is predominantly related to

Answer 15

Influx of sodium