PSYCH 101 Chapter Notes - Chapter 3: Myelin, Action Potential, Axon Terminal
Document Summary
Basic building blocks of the nervous system. 100 billion at birth, lose 10,000 every day. Contains biochemical structures needed to keep the neuron alive. Nucleus carries genetic information that determines how the cell develops and functions. Branch-like fibres that emerge from the cell body. Collect messages from neighbouring neurons and send them to cell body. Extends from cell body, conducting electrical impulses to other neurons, muscles, or glands. Connect with dendritic branches from numerous neurons. Glial cells surround neurons and hold them in place. Also manufacture nutrients, form myelin sheath, absorb toxins and waste. Guide newly divided neurons to place in brain during development. Blood-brain barrier prevents substances from entering brain. Inside of neuron is more negative, causing it to be more electrically negative. Resting potential across the membrane: -70 mv. Action potential (nerve impulse) is a sudden reversal in neuron"s membrane voltage. Depolarization - changes from 70 mv to +40 mv.
