Post on 13-Jan-2016
description
The Nervous System & its Cells
Central (inside skull & spine)
BrainSpinal Cord
Divisions of the Nervous System
Peripheral (outside skull & spine)
Nerves
Central Nervous System
Brain
Divisions of the human brain
Specialization of function
Different regions of the brain are associated with different function
Spinal Cord Reflex
Spinal cord lesion
Ouch! That hurts, dude!
Group activity
- Would sensation be abolished by:- a spinal cord lesion?- polio?
- Would the reflex be abolished by: - a spinal cord lesion? - polio?
Somatic System:
- controls voluntary muscle
Autonomic System:
- controls glands & internal organs- has two subcomponents
- Sympathetic (adrenaline): arousal- Parasympathetic: calm
Peripheral Nervous System
Levels of Investigation Brain Areas
(visual system)
Cells (neurons)
Molecules (neurotransmitters)
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Neurons: Its many shapes & sizes
Neuron: basic parts
Cell Body football field
Dendrite Campus
Axon wide a street
Axon long as Philly - Ohio
Cell membrane thick as pinky finger
Synaptic cleft thick as thumb
# synapses 10.000 (same number as Villanova students)
Some axons are wrapped burrito-style by fatty cells (glial cells) - increases speed at which neurons communicate)- white in color (white matter vs gray matter- is destroyed by multiple sclerosis
axon terminals
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Neuron: its physiology
What makes neurons different from other cells?
Neuron’s cell membrane is electrically charged (interior is more negative)
Neurons influence each other’s charge (‘communicate’)
Neurons process and transmit electrical impulses
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How do neurons process and transmit electrical impulses?
A. dendrites receive input from other neurons
B. axon sends neural impulse to axon terminal
C. a neurotransmitter (NT) is release and makes contact with another neuron (synapse)
Communication Steps
• NT is released from pre-synaptic neuron
• NT binds to receptors in post-synaptic neuron
• Opens Na+ channels
• Sodium rushes in (activation)
• If enough Na+ rushes in => depolarization (action potential)
• NT released by post-synaptic neuronPost-synaptic neuron
Synapse
Pre-synaptic neuron
Other important facts
Various Neurotransmitters (NT):- Dopamine
- Adrenaline
- Serotonin
- Acetylcholine
For each NT,various receptors
- nicotine & muscarine
Drugs can act by
- modifying amount of NT, or
- binding to receptor (nicotine)
The net effect on neuron could be:
- activation (action potential)
- inhibition