Skeletal System Parts | Human Skeletal System Function and Bone Structure

Skeletal System Parts: Skeletal System is the bony framework of the body. The main parts of the skeletal system consist of bones, ligaments and cartilage.

Human Adult skeletal system consists of 206 bones, where as in infants there are 270 bones.

Functions of the Skeletal System

The main functions of the skeletal system are:

• Skeletal System is a supportive system of our body.
• Skeletal system is a protective system in protecting our internal organs like brain, heart, lungs, ureter etc.
• Helps in the absorption of vitamin D and minerals like calcium etc.
• Skeletal system helps in the production of blood cells like Red Blood Cells and White Blood Cells.
• This system helps in the storage of minerals like calcium, potassium and phosphorous.

3D illustration of human skeleton system. Photo courtesy of Somkiat Fakmee/Freedigitalphotos.net

Structure of Bone

The bones consist of proximal epiphysis, distal epiphysis and diaphysis or shaft. If there is a small projection, it is called as tubercle and if it is big it is known as tuberocity.

In the middle part of the bone there is an area which consists of yellow bone marrow and red bone marrow. Red bone marrow is the place for producing RBC and Yellow bone marrow helps in storing the fat cells. If there is a round portion on the bone it is known as process.

As bone is a living tissue, it needs the supply of oxygen, blood and needs to conduct nerve impulses, this place is known as foramen. There is a cavity called as bursa.

Types of Layers in the Bone

Bone is composed of two layers namely:

• Compact Tissue and
• Spongy or Calcareous Tissue

A long bone comprises of both these layers.

Different Types or Shapes of Bones

• Long Bones : Bones of Extremities
• Short Bones : Bones present in digits
• Flat Bones : Bones of rib cage and skull
• Irregular Bones : Bones that are present in the vertebral column
• Sesmoid Bone : Triangular bone (Patella)

Divisions of Skeletal System

Skeletal system can be divided into two divisions

• Axial Skeletal System
• Appendicular Skeletal System

Axial Skeletal System

The Axial Skeletal system consists of Skull (Cranium), Sternum, Ribs and Vertebral Column.

Appendicular Skeletal System

Appendicular Skeletal System consists of upper limbs, lower limbs, shoulder girdle and pelvic girdle.