Skeletal System Protecting your body

Skeletal System System of bones and cartilage protecting your body and your vital organs while producing and storing blood

Parts of Skeletal System Axial- center Appendicular- appendages Vertebral column- spine Thoracic Cage- ribs Pectoral girdle- shoulders Pelvic girdle- hips

Joints- where bones connect Cartilaginous- bones connected by cartilage- cushions, but only allows slight movement Fibrous- non-moveable- thin layer connects bones Synovial- allows free movement- often have a meniscus to absorb shock between the joints

Examples Cartilaginous- lower ribs Fibrous- skull bones Synovial- knee, shoulder, hip, fingers

Types of Bone Bone has three main layers – Periosteum- Outer surface of bone. Connects to ligaments and tendons – Compact bone- makes up outer portion under periosteum. A solid hard layer – Spongy bone- inner part of bone, matrix of material with many gaps

Types of Bone

Parts of a Bone Epiphysis- top and bottom of bone, where connects to other bones Diaphysis- the “shaft” of the bone, thinner

Bone Cells Osteocytes- small cells within the bone- many together make compact bone Osteoblasts- create bone tissue Osteoclasts- break down bone tissue

Marrow Cells active in the spongy section of the bone- – Work in making both red and white blood cells Yellow marrow/pink marrow

Marrow Transplant Donors chosen based on the receptors on cell surfaces- chosen to be as close a match as possible – Patient cells killed – Cells from donor given to patient – Patient gets new immune system

Bone Diseases Rickets Arthritis Spina Bifida Bone Cysts and Spurs Osteogenesis Imperfecta

Rickets Deficiency of vitamin D (with others) causes brittle formation of bones. Often characterized by bowed legs.

Arthritis Pain and inflammation of joints Often caused by excess wear over time

Spina Bifida Very common birth defect linked to folic acid intake of mother during pregnancy Baby born without closure of spinal column- spine often outside of body

Bone Cysts and Spurs Cyst- small fluid-filled capsule in the bone Spur- Small growth on bone, often at site of joint- can cause severe pain

Osteogenesis Imperfecta Mainly genetic dominant trait Causes single AA substitution resulting in poor bone formation – Leads to very weak bones that are easily broken

Osteogenesis imperfecta posterchild