The Skeletal system

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The Skeletal system

• Your bones

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Functions

• Why do we need bones?
• Structure without our bones we would simply be
  a big pile of mush
• Protection our bones provide important organs
  their much needed protection
• Movement combine with muscles to allow us to
  move
• Creates blood cells- in bone marrow
• Stores minerals specifically calcium

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Bone Facts

• The adult human skeleton usually consists of 206
  named bones.
• These bones can be grouped in two divisions
  axial skeleton and appendicular skeleton.
• The 80 bones of the axial skeleton form the
  vertical axis of the body. They include the bones
  of the head, vertebral column, ribs and
  breastbone or sternum.
• The appendicular skeleton consists of 126 bones
  and includes the free appendages and their
  attachments to the axial skeleton.

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Bone types

• Man has evolved with bones specialized into four
  main types, each with a different role-
• The long bones - eg- in the limbs, they are
  thin, hollow and light, they play as essential
  role in all types of movements.
• Flat Circular bones - eg- bones that form the
  spine or vertebral column
• Long Circular Bones - eg. Ribs, they are strong
  but elastic giving the chest the flexibility and
  springiness it needs for breathing.
• Flat irregular bones - eg- shoulder, blades,
  hips and skull these are strong but light and
  protect delicate organs, such as the brain.

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Skull
Mandible
vertebrae
Clavicle
Sternum
Scapula
Xiphoid process
Humerus
Ribs
Pelvic bone
Sacrum
Ulna
Radius
Carpals
femur
Patella
Tibia
fibula
tarsals
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Fun facts

• The human hand has 27 bones your face has 14!
• The longest bone in your body? Your thigh bone,
  the femur -- it's about 1/4 of your height. The
  smallest is the stirrup bone in the ear which can
  measure 1/10 of an inch.
• Did you know that humans and giraffes have the
  same number of bones in their necks? Giraffe neck
  vertebrae are just much, much longer!
• You have over 230 moveable and semi-moveable
  joints in your body.

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Joints

• Hinge joint a joint that hinges just like a
  door.
• Examples- elbow, knee and fingers

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Joints

• Ball and Socket joint
• Examples hips and shoulders

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Joints

• Ellipsoid joint has a lot of movement just like
  the ball and socket joint. But a little more
  limited.
• Examples wrists and ankles

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Joints

• Pivot joints allow rotation around an axis. The
  neck and forearms have pivot joints. In the neck
  the occipital bone spins over the top of the
  axis. In the forearms the radius and ulna twist
  around each other.

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Joints

• Gliding joints have limited movement. Allows
  bones to slide against one another
• Example heel of foot