Download Nervous System

Nervous System
Relax…It’ll be okay…
Homeostasis
• Keeping things in
balance
• “Homeostasis is the
process by which an
organism keeps
internal conditions
relatively constant
through feedback
loops”
The Nervous System
• The nervous system controls and coordinates
functions throughout the body and responds
to internal and external stimuli
Neurons—The “Wires”
• This is the basic unit of the nervous system
How are nerves organized?
• 1. Brain and spine are the “Central Nervous
System” (CNS)
CNS Continued
•
•
•
•
Cerebrum—cerebral
cortex
Cerebellum—muscle
balance and function
Brain stem—connects to
spine and controls
important functions
Thalamus and
Hypothalamus control
inputs and responses
–
Sight, memory, emotions
Spinal Cord (CNS)
– It is the main
communication
link between the
brain and the rest
of the body.
Always count away from the brain.
The Peripheral Nervous System
(PNS)
• These are all of the nerve
cells not part of the brain
and spinal cord
• Both motor and sensory
divisions
– Motor = movement
– Sensory = sight, hearing,
taste, smell
PNS splits into two systems…
• Somatic Nervous
System = regulates
activities under
conscious control
PNS Splits into two systems
• Autonomic Nervous
System = regulates
automatic or
involuntary activities
– Sympathetic =
increases heart rate
when running
– Parasympathetic =
decreases heart rate
when resting
Nerve Impulses
• Ion pumps (+ on
one side, - on
another) create
a current similar
to the flow of
electricity
through a wire.
Nerve Impulse Animation
Watch This
How does the nervous system
maintain homeostasis?
•
•
•
•
1.
2.
3.
4.