1. Bones and Skeletal Tissues
Chapter 6
Bones and Skeletal Tissues

2. Section 1
Skeletal Cartilage

3. Skeletal Cartilages Skeletal cartilage
Made of some variety of cartilage tissue which consists mostly of water.
Hyaline cartilages: provide support with flexibility
1. articular cartilages: cover ends of most bones at movable joints
2. costal cartilages: connect ribs to sternum
3. respiratory cartilages: larynx (voicebox) reinforce airways
4. nasal cartilages: support external nose

4. Skeletal Cartilages
Elastic cartilages: contain more stretchy elastic fibers so they are better able to stand up to repeated bending
Found in only two skeletal locations:
External ear
Epiglottis (flap that bends to cover larynx when we swallow)
Fibrocartilages: highly compressible and have great tinsile strength
Intermediate between hyaline and elastic
Padlike cartilage of knee and between vertebrae

5. Growth Of Cartilage
Bone has hard matrix, cartilage has a flexible matrix that can accommodate mitosis
Provide new skeletal growth
Grows in two ways:
Appositional growth:
Growth from outside
Iterstitial growth
Growth from the inside
Cartilage growth usually ends during adolescence when the skeleton stops growing

6. Classification of Bones
There are 206 bones in the human skeleton (adult)
Divided into two different groups
Axial
Forms the long axis of body; skull, vertebral column, rib cage
Protecting, supporting, or carrying other body parts
Appendicular
Bones in upper or lower limbs and girdles (shoulder/hips)
locomotion

7. Classification of Bones
For the most part, bones are classified by their shape:
Long
Short
Flat
irregular

8. Classification of Bones
Long bones
Longer than they are wide
All limb bones but patella and wrist/ankle bones
Short bones
Roughly cube shaped
Wrist and ankle bones
Sesmoid bones: type of short bone (shaped like seseme seed) form in a tendon - patella

9. Classification of Bones
Flat bones
Thin, flattened, usually a bit curved
Sternum, scapula, ribs, and skull bones
Irregular bones
Complicated shapes that fit none of the other catagories
Vertebrae and hip bones

10. Functions of Bones Support Protection Movement
Provide framework that supports the body and cradles its soft organs
Protection
Fused bones of skull protect brain, vertebrae protect spinal cord, etc…
Movement
Use bones as levers to move the body and its parts (walk, grasp, breathe); design of joints determines the types of movement possible

11. Functions of Bones Mineral and growth factor storage
Reservoir for minerals, most importantly calcium
Mineralized bone matrix stores important growth factors such as insulin
Bone cell formation
Most blood cell formation occurs in the marrow cavities of certain bones