What is structure A material makes up the most?

The articular cartilage at the ends of long bones is formed from hyaline cartilage.

5 Types of Bones

1. Long

2. Flat

3. Short

4. Irregular

5. Sesamoid

Flat Bones

Protect Internal Organs

- Ribs, Sternum, Scapulae, Cranial Bones

Long Bones

Supports Weight & Facilitate Movements

- Humerous, radius, ulna, meacarpals, metatarsal, Tibia, fibula, femur.

Short Bones

Cube like shaped

- Tarsals and Carpals.

Irregular Bones

Complex Shapes

- Vertebrae and Sacrum

Sesamoid Bones

Reinforce Tendons.

7 functions of bones

1. Support

2. Protection

3. Anchorage Skeletal Muscles ( for tendons )

4. Mineral Storage ( calcium and phosphate )

5. Blood cell Formations

6. Triglyceride ( fat storage )

7. Hormone Production ( produces osteocalcin )

Osteoclasts

Osteoclasts are the bone cells that break down bone. If they were activated more than normal, you should expect to see bone loss.

Anatomy of Bones

Compact Bones : dense, smooth- looking external layer of compact

Spongy : honeycomb looking of spongy bone. ( made up of tissues ( cross - hatching called trabeculae )

Traveculae : helps bone resist stress. ( also find bone marrow )

2 different bones marrow

red : produces blood cells

yellow : stores energy as fat

Epiphyses

flared ends, bones shaft

diaphysis

has medullary cavity thats filled with yellow marrow

Structural Units of Bones

1. Osteons : cylindrical, structures that ru parallel to bones axis.

2. each tube of osteon is called Lamellae

- ( filled with collagen fibers that run in the same direction )

- goes different directions to reinforced resistant of torsion stress. ( twisting )

3. central canals : holds nerves, veins and arteries. Tucked in a tiny lacunae spaces ( gaps ) ( which helps store osteocytes )

4. Osteocyte ( mature bone cells that monitor & maintain your bone matrix )

5. Osteoblasts ( bone makers )

6. Osteoclasts ( bone breakers )

Bone Remodeling

1. Resorption ( tear down process ) : secrete both a collagen - digesting enzyme and a acidic hydrogen ion mixture that dissolves the calcium phosphate, releasing its components back into the blood.

2. adoptosis : cells self destruct.