1. G) Remodeling of Bone 1.In an adult, bone is constantly broken down and built up again. 2.Osteoclasts break down bone, remove worn cells, and help place calcium into the blood. 3.After about three weeks, osteoclasts are replaced by osteoblasts and new bone is made. 4.Calcium is removed from the blood and osteocytes are made.

2. 4. Adults require more calcium in their diet than do children in order to promote the work being done by the osteoblasts. 5. Otherwise, osteoporosis (a condition in which weak and thin bones easily fracture) may develop.

3. H) Bone Repair 1. Repair is required after it breaks or fractures. 2. Bone repair occurs in a series of four steps: a) Hematoma: within 6-8 hours after a fracture, a hematoma (mass of clotted blood) forms which results from blood escaping a ruptured blood vessel. b) Fibrocartilaginous callus: tissue repair begins. Fibrocartilage fills the space between the ends of the broken bone. Lasts for about 3 weeks.

4. c) Bony callus: osteoblasts produce trabeculae of spongy bone and convert the fibrocartilaginous callus to a bony callus. This callus joins the broken bones together and lasts about 3-4 months. d) Remodeling: osteoblasts build new compact bone at the periphery. Osteoclasts reabsorb the spongy bone, creating a new medullary cavity.

6. 3. In many ways bone repair is similar to bone development. 4. The exception is that a hematoma forms as a result of injury and fibrocartilage develops, not hyaline cartilage.

7. I) Naming of Fractures 1. The naming describes what kind of break occurred. 2. There are 6 types of fractures: complete, incomplete, simple, compound, impacted, and spiral. 3. Complete fracture: bone is broken clear through 4. Incomplete fracture: the bone is not separated into 2 parts

8. 5. Simple fracture: fracture that does not pierce the skin 6. Compound fracture: fracture that does pierce the skin 7. Impacted fracture: the broken bones are wedged into each other 8. Spiral fracture: occurs when the break is ragged due to twisting of the bone

9. Oblique= Complete Comminuted= same as Impacted VIDEOS- if you are at all squeamish, then please do not watch the last two videos. 1.Healing ProcessHealing 2.Fracture Compilation *Epic*Fracture 3.Injury Compilation (Slow Mo)Injury