Skeletal System
Functions – allows you to walk, run, jump, bend, lift and carry
1) Supports your body
2) Protects internal organs
3) Red Blood Cells (RBC) and white blood cells (WBC) produced in bone
marrow
4) Principal storage for minerals such as calcium and phosphorus
Structures – 2 main parts
1) Axial – includes skull, sternum, ribs and vertebrae
2) Appendicular – includes 126 bones of shoulders, arms, legs, hands
and feet
Ossification – the process of change of bone from cartilage to bone
Periosteum – membrane that surrounds a bone that allows blood vessels to
branch into the bone for nourishment; “shrink wrap;” allows you to feel pain.
Types of bones
1) Long bones – bone with a longer shaft with knobs on each end (Ex:
femur, humorous)
2) Short bones – bone with a shorter shaft with knobs on each end (Ex:
Phalanges – bones of the fingers, carples – bones of the hand)
3) Flat bones – flat in appearance (Ex: skull, sternum)
4) Irregular bones – Weird in shape (Ex: wrist, ankles, calcaneous)
Joints – point where two bones meet (they do and do not move)
Immoveable – do not move (skull, where sternum meets ribs)
Moveable – do move (knee, elbow)
Type
Example
Description
Hinge
Knee, elbow
Moves only in one
direction (like a door)
Ball and Socket
Hips, shoulder
Rotates in all directions
(circumduction)
Gliding
Wrists, ankles
Move over one another
Pivot
Between neck and first
Allows your head to
vertebrae
move up and down and
side to side
Ligaments – connect bone to bone
Tendons – connect muscle to bone
Problems with Skeletal System
1) Fractures A) Closed – when bone is broken and skin remain closed
B) Open – when bone is broken and sticks through the skin
C) Complete – bone is broken completely in half
D) Hairline – when the break “spiders” up the bone or appears on
the x-ray as a line.
2) Scoliosis – curve in the spine in an “S” shape that usually develops
during puberty. Treated by observation, brace, or surgery (only in
extreme cases)
3) Osteoporosis – disease where the bone becomes brittle with age and
breaks easily
4) Sprains and strains – slight movement past normal range of motion.
Ligaments may be stretched or torn.
A) Care – R.I.C.E. R – rest, I – ice, C – compression, E – elevation
5) Dislocation – bone slips out of normal position and either pops back
into place (subluxation) or stays out (complete dislocation)
6) Torn cartilage – caused by severe twist or blow
A) Care – R.I.C.E. or sometimes arthroscopy surgery to cut away the
tear.