L3.1 Action Potential

Question 1

what is the purpose of recording the resting membrane potential?

Answer 1

measures the potential difference between the outside electrode and electrode inside the cell;
measures the electrical potential difference across the membrane from ICF to ECF

Question 2

(see notes for transmembrane potential diagrams)

Answer 2

(see notes for transmembrane potential diagrams)

Question 3

what is the function of the sodium-potassium pump?

Answer 3

actively pumps potassium back into the cell and sodium out of the cell

Question 4

what is the difference and types of graded potentials and action potentials?

Answer 4

graded potentials: temporary changed in membrane voltage
- synaptic potentials (neurons)
- endplate potentials (skeletal muscle)
- pacemaker potentials (cardiac cells)
action potentials: consists of a swift change in membrane potential going from negatively briefly to a positive value and back again (all or nothing)
- signal conduction in neurons
- contraction of skeletal and cardiac muscle

Question 5

what is depolarisation?

Answer 5

decrease in potential; membrane less negative

Question 6

what is repolarisation?

Answer 6

return to resting potential after depolarisation

Question 7

what is hyperpolarisation?

Answer 7

increase in potential; membrane more negative

Question 8

(see notes for more diagrams explaining graded potential)

Answer 8

(see notes for more diagrams explaining graded potential)

Question 9

(see notes for more diagrams explaining active potential)

Answer 9

(see notes for more diagrams explaining active potential)