Skeletal system
The Functions of the Skeletal System
- Provides support for the body, giving it its shape and form
- Offers protection for vital organs such as the brain, heart, and lungs
- Assists in body movement in conjunction with muscles
- Generates red and white blood cells in the bone marrow
- Acts as a storage area for minerals, especially calcium and phosphate
The Structure and Types of Bones
- The human body has 206 bones which are classified into four major types: long, short, flat, and irregular
- Long bones, such as the femur and humerus, support weight and facilitate movement
- Short bones, like those in the wrist and ankle, provide support and stability with little to no movement
- Flat bones, like the scapula and skull, provide protection to internal organs
- Irregular bones, such as the vertebrae and mandible, protect internal organs and support weight
The Composition of Bones
- Composed largely of collagen, a protein that provides a soft framework, and calcium phosphate, a mineral that adds strength and hardens the framework
- The combination of collagen and calcium phosphate makes bone both flexible and strong to withstand stress
- Contains living tissues such as bone cells, fat cells, and blood vessels
Joints of the Skeletal System
- Joints are where two or more bones meet, facilitating movement and providing mechanical support
- Fibrous joints are immovable, such as the sutures in the skull
- Cartilaginous joints allow limited movement, an example being the spine
- Synovial joints are freely movable and are the most common type of joint in the body. They include hinge joints (e.g., elbow, knee), ball-and-socket joints (e.g., shoulder, hip), and pivot joints (e.g., neck)
Effect of Activity on the Skeletal System
- Regular exercise increases bone density and reduces risk of osteoporosis
- High-impact weight-bearing exercises stimulate the growth and strengthening of the bone matrix
- Regular activity also improves joint flexibility and range of motion
- Excessive or incorrect exercise can lead to injuries, including stress fractures and strained muscles
Musculoskeletal Conditions
- Osteoporosis is a condition that weakens bones, making them fragile and more likely to break
- Arthritis is a common condition that causes pain and inflammation in a joint
- Fractures involve a break or a crack in a bone
- Strains and Sprains are injuries that involve the stretching or tearing of ligaments or tendons