Psychology 1000 Chapter Notes - Chapter 3: Otto Loewi, Axon Terminal, Somatic Nervous System

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Mark Holden

Document Summary

Neurons: basic building blocks of the nervous system, three main parts: 100 billion at birth, lose 10,000 every day: cell body or soma. Contains biochemical structures needed to keep the neuron alive. Nucleus carries genetic information that determines how the cell develops and functions: dendrites, axon. 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. Nerve conduction: neurons surrounded by salty liquid environment, high concentration of sodium (na+) o, resting potential across the membrane: -70 mv. If potentials aren"t very strong, the neuron will be partially depolarized, but not enough for action potential. If strong enough, graded potential reaches action potential threshold about 55 mv (obeys all-or-none law: graded potentials changes membrane potential by acting on tiny protein structures in the cell membrane called ion channels. Open channels allow rushing in of na+, making neuron less negative.