Nervous System

Supplies information about internal and external environment

Parts:

Brain

Spinal cord

Nerve fiber

Sensory receptors

1st part of the system:• Autonomic nervous

system:• Controls the

automatic functions

Respiratory system

Digestive system

Eyes

Heart

Blood vessels

Glands

2nd part of the system:

Central Nervous SystemControls

• Movement

• Communication

Has 2 parts:

1.Spinal cord and brain

1.Peripheral nerves

Nerves:

• Bands of white tissue

• From central nervous system and ganglia and extend to all parts of the body

2 kinds of nerves:

1. Send impulses to the brain over sensory fibers -

2. Carry commands back from the brain over motor fibers

Sense Organs/Receptors:

• Nerve endings receiving stimuli from the outside

General sense organs:Respond to

pain, touch,

temperature

Special Sense Organs:Respond to

smell, sight,

taste, and

hearing

Nerves follow the course of the arteries

Exp: telephone wires – contain many separate lines in a bundle

3 main parts of the brain:

1. Brain stem

2. Cerebrum

3. Cerebellum

Brain Stem (primitive brain)

• Contains nerve centers that control heartbeat, respiration, temperature, etc…

Cerebrum (brain)

• Performs functions of memory, intelligence, and emotional response

Cerebellum:

• Controls muscular coordination, balance, equilibrium

• Smaller than cerebrum

Ganglia:

• Secondary nerve centers located along spinal cord

• Receive and dispatch nerve impulses that do not have to reach the brain

• Exp: heat, pain, excessive pressure, reflexes