 Leg
Circle Demo
 Why is it hard to read when
someone is talking?
 How can you space out while
driving and not crash?
 The
answer to these questions
and more to come…
Central & Peripheral Nervous
Systems
Ch. 36.1
I. Central Nervous System
A. Central Nervous System
(CNS)
1. Brain & Spinal Cord
2. Coordinates the body’s
activities
I. Central Nervous System
3. Spinal Cord
a. Most efficient part
b. Capable of multitasking
1) walking
2) talking
3) driving
I. Central Nervous System
B. Peripheral Nervous System
(PNS)
1. Made of nerves that carry
messages between the CNS
and the rest of the body
2. The CNS & PNS allow your
body to make rapid changes in
response to the environment
I. Central Nervous System
C. Three Main Parts of brain
1. Cerebrum
2. Cerebellum
3. Brain Stem
a. Midbrain
b. Pons
c. Medulla Oblongata
I. Central Nervous System
D. Cerebrum/Cerebral Cortex
1. Cerebral Cortex- Folded
mass of grey matter covering
the cerebrum
2. Handles new situations,
problem solving, speech,
memory and conscious
movements
I. Central Nervous System
3. Can only handle ONE thing
at a time
4. Learning occurs here, but it
isn’t pretty at first
a. It takes deep sleep to reorganize and cull the dendrites
started throughout the day
I. Central Nervous System
5. Left side of the cerebrum
is more “logical”
a. Handles language,
math and music
b. Develops earlier in
males and is used more
in males
I. Central Nervous System
6. Right side of the brain is
more “abstract”
a. Handles emotion,
intuition and art
b. Women use both sides
of the brain equally
1) Recover better from
brain injury
I. Central Nervous System
7. Corpus Callosum- The
bridge between the left and
right sides
I. Central Nervous System
E. Cerebellum
1. Handles balance, posture &
coordination (motor skills)
a. Injury to this region
causes jerky movements
2. Often receives directions
from the cerebral cortex which
cause muscles to move
I. Central Nervous System
F. Brain Stem (AKA Fishbrain)
1. Runs the body
a. Heart, lungs, etc
b. Paralyzes your
muscles when you sleep
c. ADD and bed wetting
are associated (until
matures)
I. Central Nervous System
F. Brain Stem (cont.)
2. Midbrain- Relay station for
impulses traveling between
the cerebrum, cerebellum and
spinal cord
a. Contains reflex centers
for sight, hearing and touch
I. Central Nervous System
F. Brain Stem (cont.)
3. Pons- Bundle of nerves
that “bridges” the
cerebellum and the rest of
the body
I. Central Nervous System
F. Brain Stem (cont.)
4. Medulla Oblongata
a. Regulates breathing,
heart rate and
vasoconstriction
b. Contains reflex centers
vomiting, coughing and
sneezing
I. Central Nervous System
G. Thalamus
1. Sorts sensory information
2. Information sent to the
wrong place causes
hallucinations
I. Central Nervous System
H. Hypothalamus
1. Survival part of the brain
a. aggression
b. anger
c. hunger/thirst
d. sex drive
e. homeostasis
I. Central Nervous System
H. Hypothalamus
2. Hypothalamus is larger in
males and animals
a. Fight or flight response
3. Very active in teenagers
II. Peripheral Nervous System
A. Peripheral Nervous System
(PNS)
1. Made of nerves that carry
messages between the
CNS and the rest of the
body
II. Peripheral Nervous System
2. Somatic Nervous System
a. Voluntary
b. Relays information to
skeletal muscles
II. Peripheral Nervous System
c. Composed of:
1)12 pairs of cranial
nerves (actually bundles
of neuron axons)
2) 31 pairs of spinal
nerves
3) All branches from the
spinal chord
II. Peripheral Nervous System
3. Autonomic Nervous System
a. Involuntary
b. Relays information to
internal organs
II. Peripheral Nervous System
c. Sympathetic Nervous
System
1) Division of the
autonomic nervous
system
2) Controls internal organs
in times of stress
a) when frightened
II. Peripheral Nervous System
d. Parasympathetic Nervous
System
1) Division of the
autonomic nervous
system
2) Controls internal organs
in times of relaxation
a) Reading, T.V.
III. Reflex
A. Reflex- An automatic,
involuntary response to a
stimulus
B. Consists of:
1. A sensory neuron
2. An interneuron
3. A motor neuron
III. Reflex
C. Travels only to the spinal
cord (faster)
1. The brain is notified soon
after so it is aware of
possible danger
a. Polysynaptic response
RECAP
-
Compare and contrast the
CNS and the PNS
What is the main function of
the cerebrum?
What is the main function of
the cerebellum?
What type of activities is the
brain stem in charge of?
RECAP
-
-
-
What is the function of the
thalamus?
What is the function of the
hypothalamus?
What are the 2 divisions of
the PNS?
RECAP
-
-
-
What is the function of the
thalamus?
What is the function of the
hypothalamus?
What are the 2 divisions of
the PNS?
RECAP
-
-
-
What are the 2 divisions of
the autonomic nervous
system of the PNS?
Explain the term reflex?
How are a monsynaptic and
a polysynaptic reflex
different