Skeletal system

Human skeleton front

Hip bone

The Skeletal system is the body part that forms the supporting structure of an organism. It can include both the biological and the anatomical aspects of cell structure, the immune system, and the body. The skeletal system serves many important functions; it provides the shape and form for our bodies in addition to supporting, protecting, allowing bodily movement, producing blood for the body, and storing minerals.

Structure

The human skeletal system is divided into two main groups: the Axial skeleton and the Appendicular skeleton. The axial skeleton includes the bones of the head, neck, chest, and spine. The appendicular skeleton includes the bones of the arms, legs, pelvis, and shoulder area.

Axial Skeleton

The axial skeleton consists of 80 bones. It is formed by the vertebral column, the rib cage, and the skull. It maintains the upright position of the body.

Appendicular Skeleton

The appendicular skeleton consists of 126 bones in the human body. It includes the pectoral girdles, the upper limbs, the pelvic girdle, and the lower limbs. The primary function of the appendicular skeleton is for movement and manipulation of objects.

Functions

The skeletal system performs several vital functions, including support, movement, protection, production of blood cells, storage of minerals and endocrine regulation.

Support

The skeleton provides the framework which supports the body and maintains its shape.

Movement

The joints between bones permit movement, some allowing a wider range of movement than others.

Protection

The skeleton protects many vital organs:

• The skull protects the brain
• The vertebrae protect the spinal cord
• The rib cage, spine, and sternum protect the lungs, heart and major blood vessels.

Blood Cell Production

The skeleton is the site of haematopoiesis, the development of blood cells that takes place in the bone marrow.

Mineral Storage

Bone matrix can store calcium and is involved in calcium metabolism, and bone marrow can store iron in ferritin and is involved in iron metabolism.

Diseases and Conditions

There are many diseases and conditions that can affect the skeletal system, including Osteoporosis, Arthritis, Rickets and Leukemia.

Gallery

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  Right lower arm

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  Lower spine

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  Humerus

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  Rib cage

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  Bone marrow in right arm

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  Vector (.svg) template

See Also

• Bone
• Human skeleton
• Musculoskeletal system
• Orthopedics