Transcript Nervous System

Identify Principle Parts of the Brain
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Identify the principle parts of the nervous
system
Describe the cells that make up the nervous
system
Describe what starts and stops a nerve
impulse (action potential)
The role of neurotransmitters
Compare the functions of the CNS & PNS
Identify the principle parts of the brain
Brain receives incoming info from spinal cord
and nerves  integrates/processes info and
 generates responses
 3 anatomical & functional divisions
1) Hindbrain – basic autonomic and vital tasks
2) Midbrain – muscle groups, responses to
sights & sounds
3) Forebrain – receives & integrates sensory
input & determines our more complex
behavior
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Connected to spinal column
 Oldest, most primitive brain division
 Most similar among animals
 Structures:
1) Medulla oblongata
2) Cerebellum
3) Pons
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Controls autonomic functions
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Heart rate
Blood pressure
Respiratory information – O2 & CO2 levels
Cough reflex
Swallowing
Sneezing
Vomiting
This is where the neurons cross over to the
other side and the left brain controls the right
side of the body and vice versa
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Located just behind the medulla oblongata
and coordinates basic (unconscious)
movements
Ensures that antagonistic muscles don’t
contract at the same time
Stores sequenced information – tying shoes
Receives sensory input from joint & muscle
receptors, balance & position receptors in ear
and visual receptors
Excess alcohol disrupts these functions
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Located just above and partly surrounding
the medulla oblongata
Contains groups of axons that extend from
the cerebellum to the rest of the CNS &
Coordinates the flow of information between
the cerebellum and the higher brain centers
Aids the medulla oblongata in regulating
respiration
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Visual & auditory sensory input passes through
the midbrain before being relayed to the higher
brain centers
Coordinates movements of the head related to
vision and hearing (e.g. turning towards sound or
flashing lights)
Controls eye movement and pupil size
Monitors unconscious movement of skeletal
muscles (smooth moves)
Reticular formation located here-neuron bundle
aids in posture, balance & muscle tone, level of
wakefulness
Emotions
 Conscious thought
 Parts:
1) Hypothalmus
2) Thalmus
3) Limbic system
4) Cerebrum
5) Glands – 2 – pineal, pituitary
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Located @ base of forebrain just above
midbrain
Coordinates some autonomic fxns, pituitary
gland, water & solute balance, T control,
carbohydrate metabolism, breast milk
production
Monitors sensory signals: sight, smell, taste,
noise, body T
Hunger center
Thirst center
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Together w/hypothalmus maintains
homeostasis & processes information
Accepts sensory signals & channels them to
cerebrum for interpretation (e.g. thalmus may
have a consciousness of pain but does not
know the location of the pain – the cerebrum
interprets the signal and we know where it
hurts)
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A group of neural pathways that connects
parts of the thalmus & hypolthalmus & inner
portions of the cerebrum
“border” – to describe structures that
bordered the basal regions of the cerebrum –
but has come to describe all neuronal
structures that control emotional behavior
and motivational drives
Limbic activities are monitored by
hypothalmus and modified by cerebrum
(social norms)
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Most developed brain region
Language
Decision making
Conscious thought
Left and right cerebral hemispheres are
connected in the middle by the corpus
callosum = enables 2 hemispheres to share
sensory-motor info
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Consists of an outer layer of mostly gray
matter (unmylenated CNS neurons, neuroglial
cells)
Inner portion consists of white matter
containing mylenated nerve axons connecting
the lower brain area to the cerebral cortex
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This structure - inner section of ascending
and descending axons and an outer layer of
cells – makes it ideally suited to
◦ direct incoming info to the proper brain region for
processing
◦ Integrate and process info
◦ Route outgoing motor activity to appropriate areas
of the body