Difficulty in joint movement (arthritis, gout, etc.)

The skeleton is responsible for producing blood cells (formed in bone marrow). It also acts as a reservoir for minerals like calcium.

Muscles are composed of bundles of specialized cells that contract and relax to create movement. The brain controls the voluntary movement of the skeletal muscles.

Membranes are thin layers of tissue that cover a body surface, line a cavity, divide a space or organ, or form the boundaries of individual cells.

Body tissues are collections of cells specialized to perform a particular function.

Connective tissues include blood, adipose tissue (fat) and various fibrous and elastic tissues (tendons, ligaments and cartilage) that hold the body together.

The skin is the largest organ in the body. It protects internal organs from the environment and regulates body temperature via perspiration.