Chapter 11

Three principle functions:

sensory input, intergration, motor input

SENSORY INPUT

nervous system senses the spider on your leg

INTEGRATION

your nervous system processes the input, and decides what should be done about it

MOTOR INPUT

your hand shakes off the spider, it's a response that occurs when your nervous system activates certain parts of your body

CENTRAL nervous system - CNS

Brain and spinal cord

PERIPHERAL nervous system - PNS

around your body

SENSORY DIVISION (afferent)

picks up a sensory stimuli

MOTOR DIVISION (efferent)

ends directions from your brain to muscles and glands

SOMATIC nervous system

voluntary (skeletal movement)

AUTONOMIC nervous system

involuntary (heart, stomach, lungs)

SYMPATHETIC

sends the body into action

PARASYMPATHETIC

relaxes the body

Neurons

small part of your nervous tissue

Glial cells

provide support, nutrition, insulation, and help with signal transmission in the nervous system; 50% of brain

ASTROCYTES

support, regulate ions, exchange materials between neurons and capillary

MICROGLIAL CELLS

defense against invading microorganisms

EPENDYMAL CELLS

create, secrete and circulate cerebrospinal fluid

OLIGODENDROCYTES

wrap and insulate, form myelin sheath

SATELLITE CELLS

surround neuron cell bodies

SCHWANN CELLS

insulate, help form myelin sheath

Soma

cell body

Dendrites

listeners

Axons

talkers

MULTIPOLAR neurons

three or more processes;one axon, bunch of dendrites

BIPOLAR neurons

one axon, one dendrite (found in special places - retina of your eye)

UNIPOLAR neurons

have only one process (found in your sensory receptors)

SENSORY neurons (afferent)

transmit impulses from sensory receptors toward the CNS; mostly unipolar

MOTOR neurons (efferent)

impulse moves from the CNS to the rest of the body; mostly multipolar

INTERNEURONS (association neurons)

impulse moves between sensory and motor neurons (in the middle): mostly multipolar