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.