Created: August 08, 2021
Modified: August 08, 2021
Modified: August 08, 2021
neuron
This page is from my personal notes, and has not been specifically reviewed for public consumption. It might be incomplete, wrong, outdated, or stupid. Caveat lector.- Parts of a neuron:
- dendrites: these branch out to receive connections from other cells
- axons: these branch out to send signals to other cells. This can be feet long.
- soma: the main body of the cell
- Most synapses are on the dendrites, but there are some on the soma and even the axons.
- The cell membrane has a 70mV charge potential across it, with negative charge inside the cell. This is caused by the sodium-potassium pump, which is a protein that uses 1 ATP to pump sodium ions (+) out of the cell, and potassium ions (also +) into the cell. This creates a chemical gradient (and a small charge gradient because it pumps 3 sodiums out for every two potassiums in, but that's not the major source of the potential gap) where there's more potassium inside the cell and more sodium outside. Both want to cross back, but the cell membrane is more permeable to potassium than to sodium, so the potassium moves outside (carrying charge out) and the sodium stays outside. This leaves more positive charge outside the cell.