BIOC32H3 Lecture Notes - Lecture 3: Nernst Equation, Depolarization, Homeostasis
Document Summary
In most cells throughout the body, homeostasis ensures that rmp is maintained. Except nerve and muscles cells which respond to changes in membrane voltage i. e they are excitable (electrical) Nerve cells (neurons) communicate with each other. In excitable cells vm changes in response to voltage: so you have lear(cid:374)ed that (cid:1006) fa(cid:272)tors i(cid:374)flue(cid:374)(cid:272)e a (cid:272)ell"s (cid:373)e(cid:373)(cid:271)ra(cid:374)e pote(cid:374)tial (cid:894)(cid:1005)(cid:895) (cid:272)o(cid:374)(cid:272) gradie(cid:374)ts of different ions across the membrane; (2) permeability of the membrane to ions. If the (cid:272)ell"s per(cid:373)ea(cid:271)ility to a(cid:374) io(cid:374) (cid:272)ha(cid:374)ges, the (cid:272)ell"s (cid:373)e(cid:373)(cid:271)ra(cid:374)e pote(cid:374)tial (cid:272)ha(cid:374)ges. This is a(cid:374) important phenomenon when understanding neuronal function: first it is necessary to go over some of the important terminology. Here is a trace of an electrical recording. Memb pot begins at rest, i. e -70mv: when the trace moves upwards (ie becomes less negative), the potential difference between inside and outside the cell is decreased, so the cell is said to be depolarised or.
