Support, Movement, and Responses

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Chapter 15

• Support, Movement, and Responses

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I. The Skin

• Skin is the largest organ of your body
• Skin Structures
• 1. Three layers of tissue
• a) epidermis outer, thinnest layer
• b) dermis layer below the epidermis. It is
  thicker and contains blood vessels, nerves,
  muscles, oil sweat glands, and other
  structures
• c) fatty layer insulates the body, where
  fat is deposited when people gain weight

Link to skin picture
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• 2. Melanin a pigment that protects the skin
  and gives it color

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• Skin Functions
• 1. Protection
• 2. Sensory Response
• 3. Formation of Vitamin D
• a) Vitamin D helps absorb calcium into your
  blood from food in your digestive tract
• 4. Regulates body temperature.
• 5. Ridding body of wastes.

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• Skin Injuries and Repairs
• 1. Injuries include bruises, scratches, burns,
  rips, and exposure to harsh conditions like cold
  dry air.
• Diseases of the Skin
• 1. Chickenpox, shingles, acne, psoriasis,
  melanoma, hives, ringworm, BO

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• Taking Care of your Skin
• 1. Wear sun screen with a minimum SPF 15.
• 2. Bathe every day.
• 3. Use deodorant/antiperspirant.
• 4. Use moisturizing lotion to prevent cracks in
  skin.
• 5. Avoid stress.

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The Muscular System

• Movement of the Human Body
• You have more than 600 muscles in your body.

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• 1. Muscle Control
• a) Voluntary Muscles muscles you are able
  to control
• skeletal muscles are voluntary
• Involuntary Muscles muscles you cannot
  consciously control
• cardiac and smooth muscles are involuntary
  muscles
• Tendons thick bands of tissue that attach
  muscles to bones

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• Working Muscles
• Pairs of muscles work together to allow parts of
  your body to move (ex. biceps and triceps)
• When 1 muscle contracts (shortens and becomes
  tighter) the other muscle relaxes and turns to
  original length.
• Muscles always pull and never push.

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• 1. Changes in Muscles
• a) Muscles that are used a lot become larger
  because there are more muscle cells added or
  muscle cells are larger.
• b) Muscles that are not used become smaller.

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• How Muscles Move
• 1. Blood carries energy rich molecules to you
  muscle cells.
• 2. Inside the muscle cells the molecules are
  changed from chemical energy to mechanical and
  heat energy.
• 3. During rest periods the blood supplies your
  muscles more energy rich molecules.
• Skeletal Muscles
• (Look at picture)

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The Skeletal System

• Functions of Your Skeletal System
• 1. Gives you shape and support.
• 2. Protects internal organs.
• 3. Muscles are attached to bones and help move.
• 4. Forms red blood cells in bone marrow.
• 5. Stores calcium and phosphorus.

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• Bone Structure
• 1. Bone Tissue
• a) Periosteum tough, tight fitting membrane
  that covers a bones surface
• b) Compact Bone
• c) Spongy Bone
• d) Marrow in cavities of long bones
• 2. Cartilage a smooth, slippery, thick layer
  at the ends of bones that acts as a shock
  absorber

Link to bone picture
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• Bone Formation
• Your bones start as cartilage.
• You start with 300 bones at birth but you now
  only have 206.
• osteoblasts bone forming cells
• osteoclasts cells that break down bone cells

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• Joints
• Joint any place where 2 or more bones come
  together
• Ligaments tough bands that hold your bones
  together
• Immovable Joints skull and pelvis

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• 1. Moveable Joints
• a) Pivot one bone moves around another bone
  that doesnt move (arm)
• b) Ball and Socket a bone with a rounded
  end that fits in a cup-like cavity in another
  bone (shoulder
• c) Hinge back and forth movement (elbow)
• d) Gliding one part of a bone slides over
  another part (wrist)

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• 3. Joint Problems
• a) arthritis starts with pain, stiffness
  and swelling of joints
• The Skeletal System
• (Look at the picture)

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The Nervous System

• Nerve Cell
• 1. Neurons nerve cells
• a) Dendrites receive messages from other
  dendrites and send them to cell body
• b) Axons carry messages away from cell body

Link to picture of neuron
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• 2. Types of Nerve Cells
• a) sensory neurons receive information and
  send messages to brain
• b) motor neurons conduct messages from
  brain to muscles
• c) interneurons relay messages from sensory
  neurons to motor neurons
• Synapse small space between nerve cells

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• The Divisions of the Nervous System
• 1. Central Nervous System includes the brain
  and spinal cord
• 2. Peripheral Nervous System all nerves
  outside of the CNS that connect brain and spinal
  cord to other body parts.
• a) Somatic System controls voluntary
  actions
• b) Autonomic System controls involuntary
  actions
• (heart rate, breathing, digestion)

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• Safety and the Nervous System
• Every mental process and physical action of the
  body involves structures of the central and
  peripheral nervous system. Any injury can be
  serious.
• 1. Reflex an involuntary, automatic response
  to a stimulus

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• The Senses
• 1. Vision
• a) cornea the transparent section at the
  front of the eye
• b) lens
• c) retina tissue at the back of eye
  sensitive to light energy
• -rods and cones 2 types of cells in retina
• d) optic nerve transfers messages to the
  brain
• e) brain

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• 2. Hearing
• a) an object vibrates producing sound waves
• b) sound waves travel through air
• c) sound waves funnel down ear canal to
  middle ear
• d) eardrum vibrates
• e) hammer, anvil, and stirrup vibrate
• f) fluids in cochlea vibrate
• g) hair cells in cochlea move
• h) electrical impulses travel down auditory
  nerve to brain

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• 3. Smell
• a) molecules in air enter nose
• b) olfactory cells are stimulated
• c) impulses are sent to the brain
• 4. Taste
• a) Saliva and food rush over taste buds on
  tongue
• b) impulses are sent to the brain