Skeletal System

Functions Support Protection -Bones protect soft body organs -Example fused bones of the skull protect the brain

Functions Movement -Skeletal muscles attach to bones by tendons, use the bones as leavers to move body parts Storage -Minerals including calcium and phosphate -Calcium in its ion state must be present in the blood stream to allow the nervous system to transit signals

Functions Blood Cell Formation - Occurs within the marrow cavities of certain bones

Skeletal System Axial -Includes the 80 bones of the skull, spine, ribs, and sternum -Protect your brain, spinal cord, heart, and lungs

Skeletal System Appendicular -Includes the 126 bones of your shoulders, arms, hands, hips, legs, and feet -Help to perform wide range of motion

Two Basic Types Compact Bone -Dense and smooth Spongy Bone - Composed of small needlelike pieces of bone and lots of open space

Classifications Long Bones -Longer than they are wider -Mostly compact bone -Limbs are mainly comprised of long bones

Classifications Short Bones -Cube shaped -Contain mostly spongy bone -Found in wrist and ankle

Classifications Flat Bones -Thin, flat, usually curved -Found in the skull, ribs, and sternum

Classifications Irregular Bones -Do not fit any other category -Vertebrae -Hip

Bone Growth During development most bones start out as cartilage (Strong flexible connective tissue) Ossification Occurs – Bone is formed, renewed, and replaced Osteoblasts – Bone forming cells Osteoclasts – Bone destroying cells

Bone Growth Diagram

Bone Remolding Essential for bones to retain normal proportions and strength Accounts for the fact that bones increase strength in areas where larger muscles are located

Joints Hold bones together Give mobility Can be divided into three types based on function Synarthrosis – Immovable Amphiarthrosis – Slightly moveable Diarthrosis – Freely moveable

Joints Division based on structure Fibrous joints – united by fibrous tissue Cartilaginous joints – connected by cartilage Synovial joints – bones ends are separated by joint cavity containing synovial fluid

Synovial Joints

Joint Problems Dislocation – Bone is forced out of its normal joint cavity Bursitis – Inflammation of the synovial membrane Rheumatoid Arthritis – Chronic inflammation disorder -Autoimmune disease – bodies immune system tries to destroy tissue -Inflammation of the synovial membrain occurs

Bone Problems Rickets – disease found in children in which the bones fail to calcify Fractures – breaks in the bone Osteoporosis – bone thinning disease -More common in women but can effect men -Result in low production of estrogen -Poor diet -Lack of weight bearing exercises

Fracture Types Closed – Bone breaks completely but does not penetrate the skin (simple) Open – bone breaks and the bone penetrates the skin (compound) Spiral Compression Impacted Greenstick