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Nervous System
In Class Notes
By: Mrs. Swineheart's Fifth Hour
Function & Divisions:
• Functions:
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sends/recieves information
process information
sends messages to organs through communication lines called
nerves
• Divisions (2)
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CNS (central nervous system)
 bodys main informatoin prcessing center
 Brain and Spinal Cord
PNS (peripheral nervous system)
 nervous tissue outside of the CNS
 delivers information to CNS
 carries messages to organs
Brain: Parts & Functions
• Brainstem = The lower portion of the brain important for
breathing and other vital functions.
• Cerebrum= The largest part of the brain; it is responsible for
learning and other conscious mental functions.
• Thalamus= A midbrain structure that plays a major role in
relaying information from the various sensory receptors to other
brain areas.
• Cerebellum= Region of the brain that plays an important role in
the integration of sensory perception
• Hypothalamus = a structure in the brain under the thalamus
that monitors activities such as body temperature and food
intake.
Parts of the Brain:
Lobes of the Brain & Functions:
• Frontal = Top front, responsible for emotion and
reasoning.
• Parietal = Middle, and is the sensory center.
• Occipital = Back, used for vision and reading.
• Temporal = Lower sides, hearing and memory.
The Neuron:
Function of the Neuron:
• conducts nerve impulses
• transmit signals at a fast rate.
• allows signals to transmit at a fast rate
through the specific and other locations.
From one neuron to the next:
Synapse: junction between two neurons or a neuron
and another cell or electrical or chemical signals are
relayed.
Synaptic cleft: tiny space where nerve signal must
be transmited.
Neurotransmitters: chemical messanger that
carries information from one neuron to another or to
another cell.
• When the action potential reaches the knob, it
causes the vestles to release the neurotransmitter
into the synaptic cleft.Receptor molecules on the
recieving neuron's membrane accept the
neurotransmitter.
Reflex Arc:
• Uses 3 Parts:
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Sensory Input
Integration
Motor Output
• Examples:
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Reflex check with doctor and hammer on your knee
Touching something hot
Feeling pain
Reflex Arc:
sensory receptors
reflex
interneurons
spinal cord
motor neurons
sensory neurons
Examples of Sensory Receptors:
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Pacinian Corpuscles- Pressure/Pain
Meissner's Corpuscles- Sensitivity to light touch
Knee Jerk- Reflex
Thermoreceptors- Detect heat/cold
Mechanoreceptors- Gauge Touch, pressure, sketch, and motion
Chemoreceptors- Located in your nose and tastebuds, sensitive to certain
chemicals
Photoreceptors- Receptive to various wavelengths of light, located in your eyes
Drugs:
• 2 Types:
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Stimulants
 Usually increase the amount of activity in the CNS
 increases amount of alertness and heart rate (nicotine)
Depressants
 Slow down CNS activity
 causes less coordination and impairs judgement
(alchohol)
Illnesses:
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Alzheimers
Tourette Syndrome
Lou Gehrigs
Huntingtons
Muscular Dystrophy
ADD
Etc.