PSYC 1f90 The Nervous system chap. note.docx - The Nervous...

The Nervous system
The central nervous system : consists of the brain which contains most of thse neurons and does most of
the computing and the spinal cord.
The peripheral nervous system is made up of two parts:

Somatic nervous system: is the network linking the spinal cord with the body and sense organs.
(SNS)

Autonomic nervous system: is the collection of axons that carry information to and from
internal organs and glands. (ANS)
How the branches of the autonomic system differ:

Sympathetic nervous system: is the division of the autonomic nervous system that coordinates
arousal while

The parasympathetic nervous system: is the part of the autonomic nervous system that quiets
the body and conserves energy.
Parts of a Neurons

The dendrites: which look like tree roots are neuron fibers that receive incoming messages.

The cell body : does the same. ( receive incoming messages)

Axon: is the fiber that carries information away from the cell body or a neuron.
Neural Function

Resting potentia l : the electrical charge of an inactive neuron.

Threshold: in neurons the point at which a nerve impulse is triggered.

Action potential: a brief change in a neuron's electrical charge.

Ion channels: Tiny opening through the axon membrane.