Download Central Nervous System

Jobs/Functions:
1. To receive info from inside and
outside of your body
2. Direct the way in which your body
responds to this info
3. Helps maintain homeostasis.
maintenance of stable internal
conditions in an organism
(ex. temperature)

Stimulus- Any change or signal in the
environment that can make an organism react

Response- What the organism does in reaction
to the stimulus
Reflex – automatic response that protects you
object spinal cord  muscles  arm or leg to
jerk

Q1: If you touched a hot object, what would be
the stimulus and response?
Q2: When you run, how does your breathing
change?
Decide if the following is a stimulus or a
response.
Tasting a lemon wedge
Smelling vinegar
Someone throwing a ball toward you
 Central Nervous System (CNS)-
Consists of brain and spinal cord.
 Peripheral Nervous System(PNS) -
Consists of series of nerve cells that
connect the brain and spinal cord to
your limbs and organs.

somatic nervous system- control
voluntary actions (using a fork or tying
your shoes)

autonomic nervous system - controls
involuntary actions (contract smooth
muscles)
 Neuron – cells that carry info
through the nervous system
(nerve cells)
 Nerve impulse – message that a
neuron carries
Axons
 Take information away from the
cell body
Dendrites
 Bring information to the cell body
Cell body - contains the nucleus
space between neurons
where one neuron can transfer an
impulse to another structure or neuron
 chemicals (neurotransmitters) from the
axon

1.
Sensory neurons: send information from
sensory receptors (senses) TOWARD the
CNS.
2.
Motor neurons: send information AWAY
from the CNS to muscles or glands
3.
Interneurons: send information between
sensory neurons and motor neurons. (CNS)
Which type of neuron conducts the
message when…
Seeing a picture
Feeling pain from skinning your knee
Moving your arm to catch a ball
Cerebrum – input from senses, controls
movement, and carries out learning and
remembering
2. Cerebellum – coordinates the actions of
muscles and helps with balance
3. Brain stem – controls the body’s
involuntary actions
1.
 Left side of brain –
mathematical and logical
thinking
 Right side of brain –
creativity and artistic ability