Download Nervous System - Holy Trinity Diocesan High School

Nervous System
A.
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B.
Function:
Relay information between the brain and the body
Information is electrical and chemical
Receptors: specialized structures that pick up information
Negative feedback to the body
Stimulus-Response: much faster change but a short lasting
effect compared to hormones
Structures:
1. Neuron:
 Nerve cell; many neurons bundle together to form a
nerve
a. Dendrites:
 Branches off the body of the neuron that
receive information from other neurons
b.
Body:
 The portion of the neuron that contains
the nucleus
c.
Axon:
 Tail of the neuron that carries
electrical information away from the
body towards the next neuron
 Insulated with myelin
d.
Terminal Endings:
 Branches at the end of the neuron that
carry information to the next neuron
2.
Synapse:
 The tiny space between two neurons
 Transmit impulses:
o Electrochemical
 Electrical: within each neuron
 Chemical: in synapse
a.
3.
Neurotransmitter:
 Chemical that is specific
 Ex. Acetylcholine
Central Nervous System
a. Brain:
1. Cerebrum:
 Major portion of the brain
 Responsible for motor functions, speech,
emotions, talking, memory
2.
Cerebellum:
 Responsible for balance and coordination
3. Medulla Oblongata:
 Brain stem
 Responsible for involuntary body functions;
breathing, heart rate
b.
4.
C.
Spinal Cord:
 Extension of the brain the relays information
to and from the periphery of the body
Peripheral Nervous System:
 Nerves that extend from the spinal cord out
to the body
Disorders:
1. Spinal Cord Injury:
 Interruption of information being relayed
between the brain and the body
 If the injury is high enough in the spinal cord
and severe enough paralysis can occur
2.
Multiple Sclerosis:
 Degenerative disorder where the myelin
sheath (protective covering of the spinal
cord) wears away
 Information between the brain and body is
interrupted
3.
Cerebral Palsy:
 Condition most occurring usually at birth due
to brain damage that causes poor control of
the body and its movements