Nervous system and Integumentary System (skin)

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Nervous system and Integumentary System (skin)
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The Nervous System

• The nervous system is the control center of the
  body it interprets the senses and enables you to
  respond
• Smell, taste, touch, sight, and sound are
  controlled by this system
• This system receives messages from inside and
  outside the body and transmits instructions about
  how to respond

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The Main Parts

• The Central Nervous system- contains the brain
  and the spinal cord.
• The Brain- the control center of the nervous
  system. It receives messages, interprets them and
  sends messages though the nervous system on how
  to respond
• Spinal Cord- composed of many nerves that links
  the brain to most of the nerves in your
  peripheral nervous system
• Peripheral nervous system- includes all of the
  nerves located outside the central nervous system

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How do those nerves send messages?

• Neurons- cells that carry information through the
  nervous system.
• Nerve impulse- the message that neurons carry
• The 3 kinds of neurons
• Sensory neuron- picks up stimuli from the
  environment and converts it into a nerve impulse
• Interneuron- carries the nerve impulse from one
  neuron to the next
• Motor neuron- sends an impulse to a muscle or
  gland, which will then react to the message

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How messages travel

• First the sensory neuron picks up the message
• The interneuron passes the message along to the
  brain which interprets it and sends a response
  back to the interneurons.
• The motor neurons pick up the message and respond
  with the action needed

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Things to know about the nervous system

• A neuron (nerve cell) is the basic unit of
  structure and function of the nervous system.
• A response that is made automatically is a
  reflex.
• Your spinal cord is made of bundles of neurons
  that carry impulses from all parts of the body to
  the brain and from the brain to all parts of your
  body.
• The spinal cord is about as big around as an
  adult thumb and 43 cm long.
• Your eyes, ears, tongue and nose are also key
  parts to this system, since they will send
  messages to your brain as well.

Nervous system review
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Integumentary System (skin)

• Purpose Your skin covers and protects the body
  from injury, infection, and water loss. It also
  regulates body temperature eliminates waste,
  gathers information about environment and
  produces vitamin D.
• Main parts
• Epidermis- top of 2 main layers of skin it does
  not have nerves or blood vessels
• Contains melanin a pigment that colors the skin
  and protects from burning.
• Dermis- thin inner layer between the epidermis
  and fat (this fat layer helps keep heat in the
  body)
• Pores- holes in skin that allow sweat to reach
  the surface.
• Follicles- structures that allow hair to grow
  (hair above the surface of skin is made up of
  dead skin cells). Oil is produced here too, that
  oil waterproofs hair and keeps skin moist and
  healthy.

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How skin does what it does!

• Protecting the body- forms a barrier that keeps
  disease-causing microorganisms outside the body.
  It also keeps water in your system, just like how
  plastic wrap it keeps food from drying out.
• Maintains temperature- by letting you sweat when
  you overheat and increasing blood flow when hot.
  This lets heat escape from the body.
• Eliminating waste- Perspiration contains waste
  materials, so when you sweat, more of that waste
  can leave the body
• Gathering information- the nerves in your skin
  provide information such as pressure, pain, and
  temperature. This information warns you if
  something in the environment is hurting you
• Produces Vitamin D- your skin cells can produce
  vitamin D which helps your digestive system
  absorb calcium which your bones need. You only
  need a few minutes in the sun to make all the
  vitamin D you need in one day.

Skin review