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QOD
If you have much, give your wealth. If you have little, give
your heart.
ROD
Nervous System
 Made up of the:
 Brain
 Spinal cord
 Peripheral nerves
 Carries messages around the body (to and from the
brain)
 Senses the environment and coordinates an
appropriate response
Central Nervous System (CNS)
 Consists of the brain and spinal cord
 Brain: protected by the skull
 Spinal cord: protected by the spine
 Both surrounded by cerebrospinal fluid
 Cushions the brain and spinal cord from injury
 Transports chemicals
 Removes waste that are produced by the brain
Peripheral Nervous System (PNS)
 Consists of the nerves that connect the body to the
CNS/brain and carries signals
 It is not protected by any structure
 Exposed to injury
Peripheral Nervous System
 Relays information about the internal and external
environments to the brain
 Also relays information from the brain to other parts of
the body to control the body’s functions and responses
Peripheral Nervous System
 Can be divided into three groups of nerves:
1) Nerves that control voluntary muscles
2) Nerves that carry information from the sensory
organs to the brain. (Ex.
3) Nerves that regulate involuntary function
(Ex.
Nervous System
 Communicates with...
 Respiratory system  change breathing rate
 Ex
 Circulatory system  change heart rate
 Ex
 Digestive system  to eat/drink more or to stop
 Ex
Nerve Tissues
 Made up of special cells called neurons
 Approximately 100 billion neurons in the brain and
also found in the spinal cord and peripheral nerves
Neurons
 Send information around the body by conducting
nerve impulses (electrical signals) from one area to
another.
 Axons are covered by myelin which is a fatty material
 Acts as an insulator - increases speed of transmission
 Prevents impulses from leaving the neuron
Nerves
 Are bundles of neurons surrounded by connective
tissue
 Allow a two-way flow of information even though each
neuron transmits information only in one direction
 Regeneration:
 Neurons in the CNS don’t easily regenerate
 Neurons in the PNS can regrow to repair a small gap
(few millimeters) between nerves
Sensory Receptors
 Receive information from the environment and send
them to the CNS to be processed
 Different parts of the brain process different senses
 Ex.
Spinal Cord
 Can act as a short cut for reflexes
 Reflexes:
 Do not require involvement of the brain
 Information is sent directly from the periphery to the
spinal cord and back.
 Ex.
Diseases & Disorders
 Multiple Sclerosis
 Damage to myelin sheath

Muscle weakness, slurred speech, difficulty walking
 Paralysis
 Damage to the spinal cord
 Concussions
 Blows to the head, whiplash
Illusions
 http://www.moillusions.com/2012/12/spinning-girl-
illusion-explanation.html
Awareness Test
 https://www.youtube.com/watch?v=yrqrkihlw-s
Ames Room
 http://www.ebaumsworld.com/video/watch/267855/
Say the colour, not the word
Today’s tasks
 Reaction Test
 Sketch and label Figure 3 on page 105
 Pg 107 #1,4,5,6