2022 Exam GIL

Question 1

Describe AP generation of non-contractile cells.

Answer 1

1. At rest (very -ve): funny channels open, Kv channels close -> slowly depolarise.
2. When close to threshold: funny channels close, T-type Ca2+ channels open -> reach threshold slowly.
3. At threshold: T-type Ca2+ channels close, L-type Ca2+ channels open -> ‘rapid’ depolarisation.
4. Very high +ve (peak ~0-10mV): L-type Ca2+ channels close, Kv channels open -> repolarisation to resting.