PS263 Lecture Notes - Lecture 2: Schwann Cell, Peripheral Nervous System, Electric Potential
Document Summary
Ions move from an area of high gradient to an area of low gradient: concentration gradients, electrical gradients (charge) Atp attaches to the pump, allowing it to change its conformation. Sodium ions attach from inside the cell and are thrown out of the cell. Atp detaches, allowing potassium to attach from the outside of the cell and to be kicked into the cell: sodium out, potassium in. More na+ out than k+ in (3:2) Resting: neuron is not firing just sitting there. Membrane does not let most ions through: k+ (cid:272)ha(cid:374)(cid:374)el (cid:373)ostl(cid:455) (cid:272)losed, na+ (cid:272)ha(cid:374)(cid:374)els (cid:858)all(cid:859) (cid:272)losed, the two channels control how the neuron fires, when the cell is resting, most of the channels are closed. If enough of the k+ ions move in, there will be more of them inside than outside, and the concentration gradient will push them out: result: Lots of potassium in the cell, little outside. Little sodium in the cell, lots outside of the cell.
