Download NERVOUS SYSTEM

 Detects
external and internal changes
 sensory
 Makes
decisions about those changes
 Integrative
 Acts
on those decisions
 motor
Sensory nerves
Bring messages from body
to central nervous system
 Can be three feet or more
in length

Integrative neurons
Found in central nervous
system
 Integrate messages
between sensory and
motor neurons

Motor neurons
From central nervous
system
 Cause movement of
muscles, glandular
secretions, etc.

Synapse transmission
Action potential is
transmitted across the
synapse by
neurotransmitters
 http://camel2.conncoll.edu
/academics/zoology/course
s/zoo202/Nervous/synapse
.html

Reflex arc
Simplest nerve pathway
 Many psychologists think
this is how all nervous
systems work

Neurotransmitters
 Can
be excitatory or inhibitory
 Excitatory increase permeability to sodium ions
 Inhibitory decrease perm to NA
Neuron pools
 In
the CNS, integrative neurons organized into
pools
Spinal cord
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Gray matter in the center
(integrative neurons)
White matter that is myelinated
fibers
31 segments each with a pair
of nerve fibers (spinal nerves)
that ennervate a different
section of the body
Covered by meninges and CS
fluid
BRAIN

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3 pounds
25% of O2 intake goes here
Covered by meninges
No pain receptors
10% of cells are neurons
the rest are support cells called
neuroglial cells
Estimated 1 quadrillion
synapses
Cerebral cortex
http://faculty.washington.edu/chudler/flash/hom.html
MORE
Cortex made of primarily
gray integrative neurons
 Areas defined by studies
on brain injured people
and by work done during
surgery
 More recently-CAT scans
and PET scans depict
brain activity

Phineas Gage
Had a railroad spike go
thro’ his skull
 Changed his personality

PET Scan
1. Cerebrum
2. Corpus callosum-connects
hemispheres
3. Thalamus-filter for sensory info
3a. Limbic system and Amygdalaemotional control and resulting
behavior
4. Cerebellum-balance and
coordination
5. Hypothalamus-connection between
nervous and endocrine system
6. Pons-breathing depth regulation
(CO2 sensors)
7. Medulla oblongata-heartbeat,
breathing reflex centers
8. Reticular formation-sleep/wake
cycle