Nervous system
Teaching Points
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1. The functions of the nervous system is to receive the information happening in both
inside and out of the body, respond to the information and lastly maintain homeostasis.
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2. The structure of a neuron includes the cell body with a nucleus, extensions called
dendrites and an axon.
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3. The central nervous system is in control of the center part of the body and consists of the
brain and the spinal cord.
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4. The peripheral nervous system controls nerves that connect out of the central nervous
system and involves both voluntary and involuntary actions
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5. The sense in our body includes vision, hearing and balance, smell and taste, and touch
Bell Work
Function Of The Nervous System
Receiving Information
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Makes you aware of what is happening around you
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Checks what is going on inside your body (ex: glucose rate in the blood)
Responding To Information
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Stimulus -> change or signal in the environment that can make an organism react
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Response -> what your body does to react to the stimulus
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Heart rate -> controlled by involuntary actions of the nervous system
Maintaining Homeostasis
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The nervous system maintains homeostasis by directing the body to respond appropriately
to the information it receives
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Ex: You get hungry when your body needs food
The Structure Of A Neuron
A neuron is a nerve cell.
Structure Of A Neuron
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Large body cell with a nucleus
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Dendrites carry impulses towards the cell body
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The axon carries impulses away from the cell body
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Bundle of nerve fiber = nerve
Kinds Of Neurons
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Sensory neuron -> picks up stimulus from the
environment and converts it into nerve impulses
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Interneuron -> carries nerve impulses from one neuron
to another
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Motor neuron -> sends impulse to muscle or gland
and react in response
How A Nerve Impulse Travels
Synapse -> the junction where one neuron transfers an impulse to another structure
There is a gap between axon tips and dendrites
Central Nervous System
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Includes the brain and a spinal cord
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Brain -> controls most functions of the body
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Spinal cord -> links brain to most of the nerves in the outer body system
The Brain and Spinal Cord
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Has three layers of connective tissue
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Between the innermost layer and the middle layer, it is filled with fluids
to protect the brain
The Brain
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Three main regions that receive and process information
1 cerebrum
2 cerebellum
3 brain stem
Cerebrum
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Interpret inputs from the senses, control movement, and carries out complex mental
process (ex: learning/remembering)
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Largest part of the brain
Left Half
Right Half
Controls right skeleton muscles
Controls left skeleton muscles
Mathematical skills
Creativity
Logical thinking
Artistic ability
Cerebellum and Brain Stem
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Cerebellum -> coordinates actions of your muscles and helps you keep your balance
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Brain Stem -> involuntary actions that occur
Spinal Cord
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The link between your brain and the rest of the body
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Vertebral column -> surrounds the spinal cord to protect them
Peripheral Nervous System
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Network of nerves that branch out from the central nervous system
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Controls both voluntary and involuntary actions
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43 pairs of nerves
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12 pairs in the brain
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31 spinal nerves
How Spinal Nerves Function
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Impulses travel on a spinal nerve both to and from the nervous system
How Each Function
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Spinal neurons -> carry both sensory and motor neurons
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Sensory neurons (Impulse :body -> central nervous system)
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Motor neurons (Impulse: central nervous system -> body)
The Somatic and Automatic
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Nerves of the peripheral nervous system can be divided into two groups
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Somatic Nervous System -> controls voluntary actions
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Automatic Nervous System -> controls involuntary actions
Reflexes
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Reflex -> automatic response that occurs rapidly without conscious control
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Some reflex actions only interact with the spinal cord
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Impulses make you feel pain for protection
The Senses
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Vision
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Hearing/Balance
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Smell/Taste
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Touch
Vision
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Stimulus of light converts into impulses to let you see
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Cornea, pupil, iris, lens, and retina are the parts of your eyes
Hearing/Balance
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Sounds is produced by vibrations
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Outer ear: gathers sound waves
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Middle ear: eardrum that vibrates sound
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Inner ear: has auditory nerves
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Semi-circular canals control your balance
Smell/Taste
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Chemicals that make you smell and taste
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50 basic odors
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5 main tastes – sweet, sour, salty, bitter, umami
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Nose and mouth work together
Touch
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Skin is the largest sense organ that contain touch receptor everywhere
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Touch, pressure, temperature change, and pain are dermis feels
Video
Activity
Right now we all will do an activity in which you all
will become part of the nervous system
Let’s All Go Out On The Roof