Section 29-4
“Nervous
System”
Write everything that is
underlined
29.4 Central and Peripheral Nervous Systems
KEY CONCEPT
The central nervous system interprets
information, and the peripheral nervous
system gathers and transmits information.
29.4 Central and Peripheral Nervous Systems
Nervous?
• Nervous doesn’t mean afraid or
uncomfortable
• It is just talking about the
nerves which are strands of
neurons or nerve cells
• Think of it as Nerve-ous
29.4 Central and Peripheral Nervous Systems
How about interpret?
• Definition of Interpret: to explain the
meaning of
• The Central Nervous System processes
and makes sense of the information it’s
given from your body
• When someone pours water over your
head how do you automatically know
it’s water?
• Your nervous system takes the info and
“tells” your brain what’s going on
29.4 Central and Peripheral Nervous Systems
Peripheral – hard to say isn’t it?
•Peripheral means
“outer edge”
•Peripheral vision
means seeing stuff
behind you
29.4 Central and Peripheral Nervous Systems
I. The nervous system’s two parts work
together
• The Central Nervous System
(CNS) includes the brain,
brain stem, and spinal cord.
• The Peripheral Nervous
System (PNS) includes four
systems of nerves.
29.4 Central and Peripheral Nervous Systems
• CNS
(Central
Nervous
System)
• PNS
(Peripheral
Nervous
System)
29.4 Central and Peripheral Nervous Systems
• The CNS and PNS pass
signals between each other
–Sensory receptor generates
impulse
–PNS passes impulse to CNS
–CNS interprets impulse
–CNS passes impulse to PNS
–PNS stimulates a response
29.4 Central and Peripheral Nervous Systems
The CNS processes information
• The brain has three
parts:
– cerebrum controls
thought, movement,
emotion
– cerebellum allows for
balance
Brain
– brain stem controls stem
basic life functions
midbrain
pons
medulla
oblongata
29.4 Central and Peripheral Nervous Systems
• The brain stem has three parts:
–midbrain controls some
reflexes
–pons regulates breathing
–medulla oblongata
controls heart function,
swallowing, coughing
midbrain
medulla
oblongata
pons
29.4 Central and Peripheral Nervous Systems
• The spinal cord controls reflexes
–sensory neuron sends
impulse to spinal cord
–spinal cord directs
impulse to motor
neuron
–does not involve the
brain
interneuron
sensory
neuron
motor
neurons
29.4 Central and Peripheral Nervous Systems
II. The PNS links the CNS to muscles and other
organs
• The somatic nervous system
regulates voluntary movements
• The autonomic nervous system
controls involuntary, functions
– sympathetic nervous
system: “fight or flight”
– parasympathetic nervous
system: calms the body,
conserves energy