Skeletal System
The Skeletal System
Structure and Functions
- The skeletal system is primarily made of bones and joints, along with supporting tissues like ligaments and cartilage.
- It serves as the body's framework, providing shape and support.
- The main function is to protect vital organs such as the heart and brain.
- It assists in movement, as skeletal muscles are attached to bones.
- The skeletal system is vital for blood cell production, which occurs in the bone marrow.
- Bones also act as a storage site for minerals like calcium and phosphate.
Types of Bones and Their Roles
- Long bones (e.g., femur, humerus) provide strength and mobility.
- Short bones (e.g., carpals of the hand, tarsals of the foot) are often cube-shaped and provide support and stability.
- Flat bones (e.g., skull, rib cage) serve a protective role.
- Irregular bones (e.g., vertebrae, facial bones) are uniquely shaped to serve specific functions.
- Sesamoid bones (like the knee) are embedded in tendons or muscles and reduce friction and wear.
Bone Composition
- Bones are living tissues made up of calcium and phosphate, giving hardness and strength.
- The layer of compact bone on the outside is dense and ensures rigidity.
- Inside, a network of spongy bone is present. It is lightweight but strong.
- The periosteum is a membrane that surrounds the bone, delivering nutrients and removing waste products.
Joint Types and Movements
- Pivot joints (e.g., neck) allow rotational movement.
- Hinge joints (e.g., elbows, knees) enable movement in one direction, similar to the opening and closing of a door.
- Ball and socket joints (e.g., shoulder, hip) allow a wide range of motion in several directions.
- Saddle joints (e.g., thumb) allow movement in two directions.
Health and Disease
- Regular exercise helps enhance bone density and reduces the risk of osteoporosis.
- Fractures are common injuries in the skeletal system due to impact or excessive force.
- Arthritis is a degenerative condition affecting joints, causing swelling and pain.
- Osteoporosis is a disorder where bones become brittle and fragile due to loss of tissue.
- Adequate intake of calcium and Vitamin D is important for strong bones. Exercise and a balanced diet are also crucial.