Transcript Nervous System Functions of Nervous System The body`s control

Nervous
System
Functions of Nervous System
• The body’s control and
communication center
• Responds to stimuli in
environment
• Initiates nerve impulses in
muscles and glands
Response to Stimuli
• Sensory Input – (int. or ext.)
–Sensory receptors
• Integration
– Processing
– Control – coordination - communication
• Motor Output
–Muscles
–Glands
Parts of Nervous System
• Central Nervous System - Association
or interneurons
–Brain
–Spinal Cord
• Peripheral Nervous System - Nerves
– Sensory – coming in
– Motor – going out
Cells of Nervous System
Ependymal
Glial
Cells
Neurons
Sensory
Motor
Schwann
Satellite
Inter
Microglial
Oligodendrocytes
Astrocytes
Neurons
• Conduct action potential (nerve
impulse)
• Electrically excitable
• Have 2 types of processes (axons &
dendrites)
• Neurons HAVE synapses that use
neurotransmitters
Neurotransmitters
• Chemicals release from axon
terminals (presynaptic knobs)
[~pitchers]
• Diffuse across synapse
• Land on receptors on dendrites
(~catchers)
1. Glial cells do NOT have chemical
synapses.
2. Glial cells have a resting potential, but
they cannot generate an action potential
3. There are many MORE (10-50 times
more) glial cells in the brain compared to
the number of neurons.
4. ~slaves
Glial Cells
Schwann
Cells
• PNS
• Insulation for neurons of PNS
Satellite Cells
• PNS
• Physical support
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CNS
Astrocytes
Star shaped
Physical & nutritional support
Anchors neurons
Transports nutrients to neurons
Digests parts of dead neurons
Cleans up brain debris
Regulates contents of extracellular
space
Microglial Cells
• Similar to astrocytes
• Digests dead neurons
Oligodendrocytes
• CNS
• Provide insulation to neurons
of CNS – myelin sheath
• (analogous to Schwann Cells)
Ependymal Cells
• CNS
• Line cavities of CNS
• Ciliated – help circulated
cerebrospinal fluid
• Similar in fx to oligodendrocytes
Nervous System Divisions
Parasympathetic
• Autonomic
• Normal operating mode
• Your “at rest & repair”
state
Sympathetic
• Autonomic
• Emergency overdrive- “fight
or flight”
• “save the brain”
–Send oxygen
–Send glucose (ATP)
Sympathetic or Parasympathetic?
• Slows heart rate
Sympathetic or Parasympathetic?
• Dilates bronchi
Sympathetic or Parasympathetic?
• Inhibits peristalsis & digestion
Sympathetic or Parasympathetic?
• Stimulates the release of
bile from the liver/gall
bladder
Sympathetic or Parasympathetic?
• Stimulates the liver to
convert glycogen to glucose
Sympathetic or Parasympathetic?
• Secretion of adrenaline from
the adrenal medulla
Sympathetic or Parasympathetic?
• Inhibits
the
external
unrinary
bladder
sphincters
Cranial Nerves
• PNS
• 12 pairs
• Come off brain
• #’d anterior to posterior
“On Old
Olympus Towering Tops
A Finn And German
Viewed
Some Hops"
Sheep Brain
• Olfactory bulb (I)
• Optic nerve II.
Oculomotor nerve III.
Trochlear nerve IV.
Trigeminal nerve V.
Abducens nerve VI.
I - Olfactory
• Sensory
• Smell
II – Optic
• Vision
• Sensory
III - Oculomotor
• Eye movement
• Eyelid movement
• Pupil Dilation
• Motor
IV - Trochlear
• Eye Movement
• Superior oblique
• Downward &
laterally
V - Trigeminal
• Somatosenosory
info (touch, pain)
from face and
head
• Muscles for
chewing
VI - Abducens
• Eye movement
• Laterally
VII - Facial
• Taste – anterior 2/3
• Somatosensory from
ears
• Controls muscles
used in facial
expressions
• Secretion of tears &
saliva
VIII – Vestibulocochlear (Auditory)
• Hearing
• Balance
Glossopharyngeal - IX
• Taste – posterior 1/3
• Somatosensory from
tongue, tonsil,
pharynx
• Controls some
muscles used in
swallowing
• Senses carotid blood
pressure
X – Vagus
• Sensory, motor, &
autonomic fxs of
viscera
• Glands
• Stimulates
digestion
• Slows heart rate
• Senses aortic blood
pressure
Spinal Accessory - XI
• Controls muscles
used in head
movement
–Trapezius
–Sternocleidomastoid
• Swallowing
XII - Hypoglossal
• Controls tongue
movement
Spinal Nerves
• PNS
• 31 pr
• Come off spinal cord
• #’d superior to inferior
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1. Cerebrum
2. Corpus callosum
3. Cerebellum
4. Reticular Activating System
5. Spinal Cord
6. Brain Stem
7. Hypothalamus
8. Thalamus
Eight small bones of the wrist:
Never Lower Tilly's Pants; Mother
Might Come Home.
Navicular, Lunate, triquetrum,
pisiform, greater Multongular, lesser
Multongular, Capitate, Hamate.
The ten essential amino acids:
These Ten Valuable Amino Acids
Have Long Preserved Life In
Man. Threonine, Tryptophan,
Valine, Arginine, Histidyine,
Lysine, Phenylalanine, Leucine,
Isoleucine, Methionine.
Functions of the blood: Old
Charlie Foster Hates Women
Having Dull Clothes. Oxygen
(transport), Carbon Dioxide
(transport), Food, Heat, Waste,
Hormones, Disease, Clotting
The excretory organs of the body.
SKILL. Skin, Kidneys, Intestines,
Liver and Lungs.