The skeleton is the body framework of the body. It forms the cavities and fossa that protect some structures, forms the joints and gives attachment to muscles. Bone marrow is involved in the formation of blood cells.

Described in two parts :  

1) Axial skeleton

2) Appendicular skeleton

1. The axial skeleton :

The axial skeleton consists of :   

• 1) Skull                                                                                      
• 2) Vertebral column
• 3) Sternum on breast bone
• 4) Ribs

2. The appendicular skeleton:

The appendicular Skeleton consists of :

• 1) The bones of the upper limbs or upper extremity
•  2) The bones of the lower limbs or lower extremity.

The axial skeleton:

1.Skull:

The skull is described in two parts :  

1) The cranium part

2) The facial part

The cranium part has :  

• Frontal bone – 1 
• Parietal bones – 2
• Temporal bones – 2
• Occipital bone -1
• Sphenoid bone -1
• Ethmoid bone – 1

The facial part has:         

• Zygomatic bones-2
• Maxilla bone-1
• Nasal bones-2              
• Lacrimal bones-2 
• Vomer bone-1
•  Palatine bones-2
• Turbinate bones-2 
• Mandible bone – 1

2. Vertebral column:

This consists of 24 movable bone vertebrae plus the sacrum and coccyx. The vertebral column is described in five parts and the bones of each part are numbered from above downwards.

• Cervical-7
• Thoracic-12
• Lumbar-5
• Sacrum (5 fused bones)-1 
• Coccyx (1 fused bones)-1 

3. Sternum or breast bone : 

This flat bone can be felt just under the skin in the middle of the front of the chest.

4. Ribs: 

There are 12 pairs of ribs which form the bony lateral walls of the thoracic Cage and articulate posteriorly with the thoracic Vertebrae. The first 10 pairs are attached anteriorly to the sternum by costal cartilage, some directly and some indirectly.

The appendicular skeleton: 

The appendicular skeleton consists of the shoulder girdle with the upper limbs and the pelvic girdle with the lower limbs.

1.The upper limbs:

The upper limbs has  :

• Clavicle-2
• Scapula-2
• Humerus – 2
• Radius – 2
• Ulna – 2
• Carpal bones (8X2) =16
• Metacarpal bones (5X2) = 10 
• phalanges (14X2) = 28

2. The lower limbs: 

The bones of the lower limbs has: 

• Hip bone -2
• Femur – 2
• Tibia – 2 
• Fibula – 2 
• Patella -2
• Tarsal bones (7X2)=14
• Metatarsal bones (5×2)=10
• Phalanges (14X2) = 28