Transcript The Nervous System - Needham.K12.ma.us

The Nervous System
Organization
-Nervous System
- Brain
Structure Meets Function
-Neuron
-Synapse
Organization of the Nervous System
• CNS & PNS
Nerve Circuit
Organization of the Brain
• 4 Main Parts
– Brain Stem
• Basic Functions
– Cerebellum
• Balance and
Coordination
– Limbic System
• Emotion
– Cerebral Cortex
• Cognition and Thinking
Responding to Stimuli
Sensory Neurons
– Connect the sense organs to the brain
Autonomic vs. Somatic Motor Neurons
Transmit the brain’s response to the
appropriate muscles
– Somatic nerves control skeletal muscles
(conscious)
– Autonomic nerves control smooth muscles
(unconscious)
Sympathetic or Parasympathetic
• Sympathetic—”Fight or Flight”
– Speeds up breathing and heart rate
– Stops digestion and urination
– Dilates Pupils
• Parasympathetic—Normal Body Maintenance
– Moderates breathing and heart rate
– Allows for digestion and urination
– Constricts Pupils
*Why do we need these responses?
*What if we are experiencing sympathetic type
responses during our normal day-to-day activities?
Functional Unit: Neuron
Multiple Sclerosis…A degenerative
Disorder
• Slow loss of ability to control muscle
movement.
• Autoimmune
• Body “eats” myelin sheath
• If myelin sheath is similar in function to
insulation on wires, why is this disease so
bad?
Action Potential--Communication
within a Neuron!
• The change in charge that travels from the
dendrite of a neuron down the axon.
• Can be represented on a graph as a nerve
impluse:
Action Potential Activity
• How does the sodium
potassium pump work?
• What is resting potential?
• How does a nerve impulse
change charge?
Website:
http://outreach.mcb.harvar
d.edu/animations/actionpot
ential.swf
QuickTime™ and a
TIFF (Uncompressed) decompressor
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Synapse--Communication between
neurons!!!
• Signals can be transmitted from one nerve to
another nerve or muscle.
Serotonin
• An example of a neurotransmitter that affects
mood, sleep, heart rate.
• Can be a cause of depression and anxiety.
– Depression—too little
– Anxiety—too much
What is depression?
What is anxiety?
Are these biological
diseases?
Treating Depression
• Prozac and Zoloft are medicines used to treat
depression.
• They are called selective serotonin reuptake
inhibitors.
• Let’s watch the commercial and see if we can
determine how it works.
http://www.youtube.com/watch?v=6vfSFXKlnO
0
Depression and Treatment
• Depression medications are bandaids for a
biological imbalance. What is meant by that
analogy?
• How might therapy help cure depression?
• Is depression genetic? Environmental? Both?
Alzheimer’s
• Memory is caused by another neurotransmitter
called acetylcholine.
• Complete the activity to see how Alzheimer’s might
be caused by an imbalance of this neurotransmitter
and how Aricept might treat (but not cure)
Alzheimer’s symptoms.
http://www.aricept.com/learnaboutalz.html
Watch the video that shows the biochemistry of
Alzheimers and how Aricept treatment works!
Schizophrenia
QuickTime™ and a
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• Overstimulation of a
neurotransmitter called
Dopamine.
• Cocaine is a mimic of
dopamine
• Treatment: Thorazine
blocks receptors and
stops signal!
Summary
• Be able to explain how
a signal is sent from one
neuron to another.
• Identify three ways to
alter the signal and
explain whether the
signal is INCREASED or
DECREASED!
QuickTime™ and a
TIFF (Uncompressed) decompressor
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Smarts and the Brain
• Does a bigger brain make you smarter?
Yes and No
Within and individual
human’s brain
Connections matter
More than size…
Active learning forms
connections!