skeletal system and Bones

What are the main functions of the skeletal system?

Support of the body, protection of soft organs, movement due to attached muscles, storage of minerals and fats, and blood formation.

What are the four types of bone classified by shape? Give an example of each.

1. Long Bones (e.g., femur), 2. Short Bones (e.g., carpals), 3. Flat Bones (e.g., skull), 4. Irregular Bones (e.g., vertebrae).

How does ossification occur in bones?

Ossification involves the formation of new cartilage at the epiphyseal plates, which is later converted to bone as older cartilage is broken down.

Compare the three types of bone cells.

1. Osteocytes: Mature bone cells. 2. Osteoblasts: Bone-forming cells responsible for bone growth. 3. Osteoclasts: Bone-destroying cells that remodel bone and release calcium.

What are the steps involved in the repair of bone fractures?

1. Hematoma formation, 2. Fibrocartilage callus formation, 3. Replacement with bony callus, 4. Remodeling to form a permanent patch.

What are the characteristics of long bones?

Long bones are typically longer than wide, have a shaft with heads at both ends, and mainly contain compact bone.

What covers the external surface of the epiphysis?

Articular cartilage covers the external surface of the epiphysis, made of hyaline cartilage to reduce friction at joint surfaces.

What is the medullary cavity and its function?

The medullary cavity is located in the shaft of long bones and contains yellow marrow in adults, which stores fat, and red marrow in infants for blood cell formation.

What is the significance of the periosteum?

The periosteum is the fibrous connective tissue membrane that covers the outside of the diaphysis and provides protection and nourishment to the bone.

What is an osteon (Haversian system)?

An osteon is the structural unit of compact bone, consisting of a central canal surrounded by concentric rings of bone.