Action Potential

Question 1

Name the steps In Action potential

Answer 1

Polarised cell, stimulus approaches, depolarisation, beginning of repolarisation, repolarisation, hyperpolarisation

Question 2

Polarised cell characteristics (action potential)

Answer 2

-At resting membrane point (-70mV)
-sodium (positively charged) concentration high outside cell
-potassium (positively charged) concentration high inside cell
-large negatively charged ions in cell

Question 3

Stimulus approaching characteristics (action potential)

Answer 3

-sodium channels open (ligand and mechanical)
-membrane potential rises

Question 4

Depolarisation characteristics (action potential)

Answer 4

-sodium voltage gated channels open (influx of sodium in cell)
-cell becomes positively charged

Question 5

Beginning of repolarisation characteristics (action potential)

Answer 5

-Sodium channels close at 30/40mV
-potassium voltage gated channels open at 30mV

Question 6

Repolarisation characteristics (action potential)

Answer 6

-potassium flows out of cell through voltage gated channels
-membrane potential becomes negative

Question 7

Hyperpolarisation characteristics (action potential)

Answer 7

-potassium voltage gated channels close
-membrane potential below -70mV
-sodium potassium pump transports 3 sodium out and 2 potassium in cell (against concentration gradient)

Question 8

What is the refractory period (action potential)

Answer 8

The time which the cell is not at -70mV/resting membrane potential