1. The Human Skeletal System Formation of Bones and Injuries to the Skeleton

2. Bone Formation  When you are born you have more cartilage than bone and this gradually changes over time in a process known as ossification.  There are 4 basic steps in bone formation.

3. Steps in Ossification  Bone cells absorb calcium.  Once absorbed, the calcium changes into calcium compounds.  The calcium compounds cannot dissolve in water so they stay in the cells of the bone  The calcium compounds harden and form bone.

4. Ossification Timeline  Ossification begins at birth and is usually completed between the ages of 18 and 25.  During this time period it is very important for you to have a healthy diet so your bones are strong.

5. Skeletal System Problems  There are times when the skeletal system is not working correctly.  This can be due to an injury or some sort of disease or disorder that affects the skeletal system

6. Fracture  A fracture is a broken bone.  There are several different types of fractures.

7. Greenstick Fracture  A greenstick fracture is a break in the bone that does not go all the way through.  The bone will be casted until new bone cells can form and the bone becomes strong again.

8. Simple Fracture  With a simple fracture the bone has broken all of the way through but the skin around the bone has not broken.  The doctor will set the bone back together and put a cast on it.

9. Compound fracture  In a compound fracture the bone has completely broken along with the skin.  The bone may need screws to hold it in place while it heals along with a cast. The skin will also need to be stitched.

10. Dislocation  Along with broken bones, injuries can result in dislocations.  A dislocated bone is one that is moved out of place. This can result in torn or stretched ligaments.

11. Arthritis  Arthritis is inflammation or swelling of joints and it can be very painful!  Most common in older people but there are also juvenile forms of arthritis.

12. Rickets  Rickets is a disease that occurs in children who do not get enough calcium and vitamin D in their diets and their bones do not form properly.  Bones become soft and weak. Children may become bow-legged as a result of rickets.