Human Musculoskeletal Anatomy

Musculoskeletal system refers to the complex system in the human body comprising bones, muscle and connective tissues. It provides support, enhances mobility and protects the organs.

The Human Skeleton consists of 206 bones and is divided into two key components: the axial skeleton and the appendicular skeleton.
The axial skeleton includes the skull, vertebral column and rib cage.
The appendicular skeleton incorporates upper limbs, lower limbs, pelvic girdle and pectoral girdle.
Bones have a core structure filled with marrow, which can produce new blood cells.

Connective Tissues such as ligaments, tendons, and cartilages allow movement, flexibility, and support.

Ligaments are tough elastic tissues present around joints that connect bone to bone.
Tendons are less elastic but have a greater strength and attach muscles to bones.
Cartilage is a flexible yet strong connective tissue that reduces friction among joints.

Muscles and Movement

Muscle tissue is divided into skeletal, smooth, and cardiac muscles. Their contraction and relaxation are the primary causes of human body movement.

Skeletal muscles or voluntary muscles are those controlled by human will, such as the biceps.
They work through a pull mechanism and always work in pairs. When one contracts (agonist muscle), the other relaxes (antagonist muscle). This allows the movement of body parts.
Smooth muscles are found in the walls of hollow machinery organs like intestines, stomach, and blood vessels. Their contraction is controlled involuntarily.
Cardiac muscles, found only in the heart, are involuntary muscles that contract to pump blood around the body.

Joints

Joints are crucial for body movements and come in various types - hinge, ball and socket, pivot and gliding joints.

Hinge joints like elbows and knees allow movement in one direction, similar to the opening and closing of a door.
Ball and socket joints (like the shoulder and hip) allow for all-round rotational movement.
Pivot joints (as in the neck) allow rotational movement.
Gliding joints provide some sliding motion, seen between the carpals in the wrist.

Disorders of the Musculoskeletal System

Common issues include arthritis, osteoporosis, and fractures.

Arthritis is a condition causing inflammation of one or more joints leading to pain and stiffness.
Osteoporosis is a disorder where bone density decreases, leading to fragile bones.
Fractures refer to breakage or crack in a bone, most commonly caused by impactful accidents or falls.

These are just basics but always refer to the syllabus for the depth of understanding required. Real exam focus should be on understanding how these parts work together to create smooth, coordinated movements and how this might revise if one part is defective or damaged.