4. Skeletal System 1- part 1 (1).pdf

The Skeletal System 1 part 1 Dr. Amani A. Mezher BSc PT, MD Rehab. MED, Faculty of Heath sciences 1 The Islamic University of Gaza.  Bone Bones are organs Bones are composed of all tissue types. Their prima...

The Skeletal System 1 part 1 Dr. Amani A. Mezher BSc PT, MD Rehab. MED, Faculty of Heath sciences 1 The Islamic University of Gaza.  Bone Bones are organs Bones are composed of all tissue types. Their primary component is osseous connective tissue. The matrix is sturdy and rigid due to calcification (also called mineralization).  Functions of Bones Support: form the framework that supports the body and cradles soft organs Protection: provide a protective case for the brain, spinal cord, and vital organs Movement: provide levers for muscles Mineral storage: reservoir for minerals, especially calcium and phosphorus Blood cell formation: hematopoiesis occurs within the marrow cavities of bones Energy storage (fat in yellow marrow)  Support and Protection Bones provide structural support and serve as a framework for the entire body. Bones protect many delicate tissues and organs from injury and trauma.  Movement Muscles attach to the bones of the skeleton – contract and pull on bone – functions as a series of levers. Storage of Mineral and Energy Reserves More than 90% of the body’s reserves of the minerals calcium and phosphate are stored and released by bone.  Hematopoiesis Blood Cell Formation Blood cell production in red bone marrow – located in some spongy bone. Red bone marrow contains stem cells – form all of the blood cell types.  Bone Classification A. Long Bones Short Bones Flat Bones Irregular Bones Sesamoid (Round) Bones  Classification of Bones: By Shape Long bones – longer than they are wide (e.g., humerus)  Classification of Bones: By Shape Short bones – Cube-shaped bones of the wrist and ankle – Bones that form within tendons (e.G., Patella)  Classification of Bones: By Shape Flat bones – thin, flattened, and a bit curved (e.g., sternum, and most skull bones)  Classification of Bones: By Shape Irregular bones – bones with complicated shapes (e.g., vertebrae and hip bones)  Classification of Bones Axial skeleton – – bones of the skull, vertebral column, and rib cage Appendicular skeleton – – bones of the upper and lower limbs, shoulder, and hip  Bone Structure - External  Cartilage protection for joints  Bone Structure - External Epiphyses Expanded ends of long bones Exterior is compact bone, and the interior is spongy bone Epiphyse Joint surface is covered with articular (hyaline) cartilage location of red bone marrow Epiphyseal line separates the diaphysis from the epiphyses  Bone Structure - External Diaphysis Tubular shaft that forms the axis of long bones Composed of compact bone that surrounds the medullary cavity Yellow bone marrow (fat) is contained in the medullary cavity Diaphysis  Bone Structure - Internal Spongy Bone- red marrow  Bone Structure - Internal Compact bone Compact and Spongy Bone  Bone Structure - Internal Medullary Cavity- yellow marrow  Bone Structure - Internal Epiphiseal Plate “Growth Plate”  Parts of a Long Bone epiphysis distal proximal diaphysis compact bone spongy bone articular cartilage periosteum endosteum medullary cavity trabeculae marrow red yellow  Structure of Short, Irregular, and Flat Bones Thin plates of periosteum-covered compact bone on the outside with endosteum-covered spongy bone on the inside Have no diaphysis or epiphyses Contain bone marrow between the trabeculae THE END