Structure of the Musculoskeletal System

The musculoskeletal system comprises two distinct yet interconnected subsystems: bones (skeletal system), and muscles (muscular system).
The skeletal system is a matrix of 206 different bones in the human body. They provide a rigid framework for support, movement and protection of the body’s internal organs.
Bones can be categorised into four types: long bones (e.g. femur), short bones (e.g. carpals in wrist), flat bones (e.g. skull), and irregular bones (e.g. vertebrae).
Joints are the points of articulation or connection between two or more bones. They facilitate movement and provide mechanical support to the body. They are classified into three types: Fibrous (no movement like in skull sutures), Cartilaginous (limited movement like in spine), and Synovial (free movement like knee or elbow).
Synovial joints come in six forms: hinge (elbow and knee), pivot (neck), saddle (thumb), plane (wrist and ancle), condyloid (wrist), and ball-and-socket (hip and shoulder).
The muscular system is made up of over 600 muscles, allowing for all types of movement. Muscles can only contract to move the body; they cannot push.
Muscles can be categorised into three types: Smooth (found in organs like the stomach), Cardiac (found only in the heart), and Skeletal or Striated (attached to bones allowing bodily movement).
Skeletal muscles always occur in pairs known as antagonistic pairs. When one muscle in the pair contracts (agonist), the other muscle (antagonist) relaxes to allow movement.
For example, when the biceps muscle in the upper arm contracts, the triceps relaxes, allowing the bending of the arm at the elbow. And conversely, when the triceps contracts, the biceps relaxes, enabling the straightening of the arm.
Muscular contractions can be classified into three types: Isonomic (muscle length doesn’t change but tension does, as in lifting a weight), Isotonic (muscle changes length with constant tension, as in normal movement), and Isokinetic (repeated contraction and relaxation of muscle, as in cycling).
Understanding the structure of the musculoskeletal system aids in appreciating how to train effectively and avoid injuries. If bones, muscles, or joints are used improperly or subject to too much stress without sufficient recovery time, injuries can occur.
Regular physical activity strengthens the musculoskeletal system, encourages bone growth and reduces bone loss during ageing, thus reducing the risk of osteoporosis. Weak muscles and inflexible joints increase the risk of injuries.
Additionally, the musculoskeletal system plays an important role in maintaining posture and balance. It also produces heat, contributing to body temperature regulation.

Remember to also revise how nutritional intake and lifestyle choices can impact the health and function of the musculoskeletal system.