Structure of the Musculoskeletal System
- The musculoskeletal system includes all the muscles and bones in the body.
- A primary function is to support the body, maintain posture and aid movement.
- The skeletal system is divided into two sections: the axial skeleton (skull, vertebral column, rib cage) and the appendicular skeleton (shoulders, arms, pelvis, legs).
- There are 206 bones in the adult human body. Each bone has a protective layer known as the periosteum.
- The skeletal system is also important for protecting vital organs. For instance, the ribs protect the heart and lungs while the skull protects the brain.
- Major components also include connective tissues such as cartilage, which cushions joints, and ligaments, which hold bones together.
- Bones are connected to each other by joints, which can be immovable (like those in the skull), slightly movable (like those in the spine), or freely movable (like the knees, elbows, hips).
- The muscular system is primarily responsible for movement. It is composed of three types of muscles: skeletal, smooth, and cardiac.
- Skeletal muscles are attached to bones and can be controlled voluntarily.
- They contract and relax to move the body parts they are attached to, and work in pairs known as antagonistic pairs - when one contracts, the other relaxes.
- Smooth muscles are found in the organs, blood vessels, and other body structures. They work involuntarily and control many types of movement within the body.
- Cardiac muscles are located in the heart. They contract and relax continually to pump blood around the body.
- The musculoskeletal system also plays a key role in maintaining homeostasis - the body's effort to maintain a stable internal environment.
- It's also an important site of production for red and white blood cells, which happens in the bone marrow.
- Regular physical activity can help keep the musculoskeletal system healthy, by strengthening muscles, improving joint flexibility, and enhancing bone density.