The Divisions and Main Structures of the Nervous System Hwa Won and Samuel
Feb 24, 2016
The Divisions and Main Structures of the Nervous System
Hwa Won and Samuel
Vocabulary• Brain: main part of central nervous system made of about
100 billion neurons• Nerve: Bundle of nerve fibers that carry sensory information• Spinal cord: Thick whitish nerve tissue enclosed by
vertebrae that links brain to most nerves• Cerebellum: largest part of brain that works over the senses
and causes skeletal muscles to move and complex mental processes
• Reflex: automatic response that comes out very quickly without control of the brain.
The Brain
• Contains about 100 billion neurons• The skull, 3 layers of connective tissue, and fluid
help protecting brain
The Cerebellum
• Keep balance of body• Organize body and thought in coordinate way
Brainstem
• Control body’s automatic actions (i.e. breathing/ heart beating)
The Central Nervous System
• It is like a control center of the body• Spinal cord links the central nervous system
with the peripheral nervous system• Brain is a part of the central nervous system• The nerves in your body work like a network
of interconnected wires
The Peripheral Nervous System
• Network of nerves other than central nervous system
• Connect nerves from central nervous system to whole body
• Impulse travel through spinal nerve in 2 directions
To/ from central nervous system
The Peripheral Nervous System (continued)
• Somatic nervous system control voluntary actions
(i.e. using fork/ tying shoelaces)• Automatic nervous system control
involuntary actions (i.e. regulating smooth muscles)
The Spinal Cord
• The vertebral column (backbone) surrounds it and therefore protects it
• It links the brain and the peripheral nervous system
• It is also protected by a watery fluid• It is about 45 cm long in men and about 43 cm
in women
Reflexes
• A rapid, involuntary response to a thread• Sometimes only the spinal cord is involved (no
brain involvement)• Used for protection, i.e. a burn after you touch a
hot surface • As your muscles contract, another impulse goes
from your hand to your brain, simultaneously • This impulse makes you feel pain
Safety and the Nervous System• Just like any other part of your body the nervous system can be
easily damaged• Concussion – an injury of the brain, when the cerebrum hits
the skull– Occurs if you hit your head very hard – Sometimes heals itself, but if not and uncured it can cause brain
damage– Wearing a helmet can prevent concussion in activities such as sports
• Spinal cord can be easily injured, too– Occurs when the vertebrae is injured– Very dangerous, it can paralyze body parts or even the whole body
Wear a Helmet!