Skeletal system HCS 1050 SLOs – 1.6 – 1.12

Functions of the Skeletal system Serve as a frame for the body Protect organs Serve as a lever for movement Form blood cells Store minerals

Functions:

Categorizing Bones Flat – ribs, cranium Short – carpals of the wrist, tarsals of the ankle Irregular – vertebrae, facial bones Long – most of the skeleton including bones of the arms and legs

Flat bones

Short Bones

Irregular Bones

Long Bones

Structure and Significance of Long Bones The long narrow shaft of long bones is called the diaphysis At the center of the diaphysis is a medullary cavity which contains bone marrow The two irregular ends are called the proximal and distal epiphysis

Long Bone Structure

Bone Marrow Red marrow is found in the spongy bone at the ends of the long bones and at the center of other bones Red marrow manufactures blood cells Yellow marrow is found mainly in the central cavities of the long bones Yellow marrow is composed of mainly fat

Bone Marrow

Bone Membranes and Cells Bones are covered on the outside (except at the joint regions) by a membrane called the periosteum This membrane’s inner layer contains cells (osteoblasts) that are essential in bone formation not only during growth but also in the repair of injuries. Blood vessels in the periosteum help to nourish bone tissue

Bone Membranes and Cells There are also nerve fibers here that register pain when a bone is fractured or when it is hit The endosteum is a thin membrane that lines the bone’s marrow cavity and is also important in bone tissue growth and repair

Compact and Spongy Bone Bone tissue or osseous tissue, is very much alive with their own blood vessels, lymphatic vessels and nerves The two types of osseous tissue are: 1) Compact bone: hard and dense Makes up the main shaft of long bones and outer layer of other bones 2) Spongy bone: Have more spaces than compact bone Found at the epiphyses (ends) of long bones

Do Now! Complete workbook pg. 101 handout exercises 7.1 and 7.2 Make sure to color the different structures on the diagram Complete workbook pg. 102 handout exercises 7.3 – 7.5