Membrane Potential

Question 1

ICF and ECF charges

Answer 1

ICF has an excess of anions
ECF has an excess of cations

Ion channels provide selective ion permeability

Question 2

Electrical gradient and concentration gradient relationship

Answer 2

Electrical gradient Opposes an ion concentration gradient across a cell membrane

All living cells have a resting membrane potential based on a separation of charge across the cell membrane

Question 3

What maintains the gradient for the Na and K ions?

Answer 3

The sodium potassium pump

Question 4

The sodium potassium pump

Answer 4

Pumps three sodium out of the cell for every two potassium into the cell per ATP molecule

Contributes towards the membrane potential

Neurons have a high number of sodium and potassium pumps to reestablish, potassium and sodium gradients necessary for action potentials

Question 5

Sodium details

Answer 5

Intracellular is less than extra cellular
potential is +67

Question 6

Potassium details

Answer 6

Extracellular is less than intracellular
potential is -95

Question 7

Calcium details

Answer 7

Intracellular is less than extra cellular
potential is +123

Question 8

Chlorine details

Answer 8

Intracellular is less than extra cellular
potential is -89

Question 9

HCO3 bicarbonate

Answer 9

Intracellular is less than extra cellular
Potential is -19

Question 10

Depolarization

Answer 10

Sodium is entering

Question 11

Repolarization

Answer 11

Potassium is leaving

Question 12

Absolute refractory. Period

Answer 12

Beginning of one action potential, when it is impossible to stimulate, and produce another action potential
Sodium channel gates are closed and inactive

Question 13

Relative refractory Period

Answer 13

Comes right after that absolute refractory. Period

If there’s another impulse or stimulus given, it could trigger a response, but only if it is a stronger stimulus

This is because the sodium channels have recovered