Download The Nervous System

The Nervous System
Functions of the Nervous System
• Control and coordinate functions
throughout the body
• Respond to internal and external stimuli
Parts of the Nervous System
• The Central Nervous System
– Consists of the brain and spinal cord
• The Peripheral Nervous System
– Consists of the nerves that are not part of
the brain or spinal cord (ex. Nerves in the
arms and legs)
Parts of the Nervous System
Peripheral
Nervous System
(nerves that are
not part of the
brain or spinal
cord)
Central
Nervous
System (Brain
and Spinal
cord)
Central Nervous System
Parts of the Brain
• Cerebrum
– Responsible for voluntary activities of the
body
– Ex.-moving the muscles
Parts of the Brain
• Cerebellum
– Responsible for coordination and balance of
the actions of the muscles
– Helps the body to move gracefully and
efficiently
Parts of the Brain
• Brain Stem
– Regulates information flow between the brain
and the rest of the body
• Thalamus
– Receives messages from the body and relays
them to the cerebrum (voluntary actions)
• Hypothalamus
– Recognizes and regulates hunger, thirst,
fatigue, and body temperature
Parts of the Brain
Cerebrum
Hypothalamus
Thalamus
Brain Stem
Cerebellum
The Spinal Cord
• The major communication link between
the brain and the rest of the body
• A reflex is a quick automatic response
to a stimulus
Neurons-cells of brain tissue
• Impulses are electrical signals carried
by the nervous system
• The cells that carry these impulses are
called neurons
Parts of a Neuron
• Cell body
– Contains the nucleus and cytoplasm
• Dendrites
– Carry impulses toward the cell body
• Axon
– Carries impulses away from the cell body
The Neuron
The Resting Neuron
• Not transmitting an impulse
• If the outside of the cell has a positive
charge and inside of the cell is a
negative charge, then the neuron is said
to be at resting potential
Where do these charges inside
the cell and outside come from?
• Sodium Potassium Pump-make changes in
notes
– Cell membrane pumps Na+ ions INTO of the
cell and K+ OUT the cell by active
transport.
– A difference in charges has to occur for
the neuron to become active and transmit
messages.
The Moving Impulse
• A neuron remains in its resting state
until it receives an impulse
• An impulse begins when a neuron is
stimulated by another neuron or the
environment
The Moving Impulse
• Na+ ions flow into the neuron and the
inside of the cell temporarily becomes
more positive than the outside
• The change from negative to positive is
called a nerve impulse or an action
potential
• The impulse travels down the axon away
from the cell body
The Moving Impulse
• As impulse passes K+ flows out of the
neuron and the resting impulse is
restored. The neuron has a negative
charge on the inside and a positive
charge on the outside.
The Synapse
• The location at which a neuron can
transfer an impulse to another cell
Neurotransmitters
• Chemicals used to transmit an impulse
across a synapse to another cell
Nervous System Feedback
Mechanisms- Glue in image
Questions from Thermoregulation
image
Stimulus: low body temperature
Response: _________________
Type of Feedback: ___________
Stimulus: high body temperature
Response: __________________
Type of Feedback: ____________
Feedback Mechanisms: glue in image
Questions from child birth image
Stimulus: baby’s head pushing on the cervix
Response:___________________________
Type of Feedback: ____________________