Electrical signals in the body (AQA A-Level Physics): Flashcards

Movement of ions across cell membranes

$-70$ mV

Polarised

High $\text{K}^+$, low $\text{Na}^+$

$\text{Na}^+$ enters, potential rises to $+35$ mV

Inside positive relative to outside

$\text{K}^+$ exits, potential returns to $-70$ mV

Nerve: $\sim$5 ms, Heart: $\sim$0.2 s

Natural pacemaker (node)

Contracts