Musculoskeletal system

From ArticleWorld

The musculoskeletal system is the body system that serves the dual functions of providing structure to the body and giving movement to the body. In humans, this consists of the bony skeleton which is attached, by means of tendons, to the various muscles that move the skeleton. Ligaments attach areas of the skeleton to other bony structures.

Types

Among animal species there are three kinds of musculoskeletal systems. Humans and other vertebrates have a solid internal musculoskeletal system. Calcified bones join together via ligaments to provide an internal firm support system. The bones are generally somewhat hollow with the inner part, the bone marrow, providing various blood cell components.

Lesser animal species, such as annelids and cnidarians, allow water to provide the necessary structure. Water fills certain areas or pouches that use hydrostatic pressure to create shape. Worms are among those that have hydrostatic musculoskeletal systems.

Arthropods, including insects, make use of an exterior skeleton, called an exoskeleton. The interior muscles are attached to the exoskeleton and allow the arthropod to move.

Anatomy

Mammals have a common basic structure. Each animal has a skull, bones involved in some sort of neck and spine, a ribcage to support and protect the heart and lungs, and long bones to support each of four extremities. Bones also support and participate in the manipulation of the distal extremities in some mammals. Hoofed animals, such as the horse, do not have specific bones at the distal extremities. Some mammals also have bones to form a tail.

Muscles attach via tendons to several bony areas. In humans, there are facial muscles that form expression, cervical muscles that control the neck movement and truncal muscles, which can flex the abdomen or extend and rotate the back. Humans also have extensor muscles, which extend the bones of the upper and lower extremities, and flexor muscles, which flex the bones of the extremities. Muscles allow for the rotation of some of these joints as well.

Disorders

The most common disorder of the bony aspect of the musculoskeletal system is a fracture of one of the bones. Upon immobilization and reduction of the bone into its proper position, the cells involved in bone formation will repair the fracture over time.

The most common disorders of the muscles of the musculoskeletal system are “sprains”, which involve a stretching injury to the ligaments, or “strains”, which involve an overuse or stretching injury of the muscle itself or of the tendon.