Bones Dr : Sherif Mohammed Zaki Assistant professor of anatomy Faculty of medicine Cairo university

Function of bone

Gives a specific shape to the body and provides it with a central axis.

2- Protects the vital organs, the skull protects the brain, and thoracic cage protects the heart and lungs.

3- Provides surface area for muscular attachment.

4- Forms the joints which make the important part of the locomotor system.

5-Transmits and supports the body weight 5-Transmits and supports the body weight. The vertebral column transmits the weight of the head and trunk to the bony pelvis then through the bones of lower limbs to the feet and lastly to the ground.

6- Forms the blood elements in the bone marrow. 7-Stores calcium salts.

Classification of the bony skeleton

According to their position in the body:

Bony skeleton is divided into Axial skeleton: Skull and mandible. Ribs Hyoid bone Vertebral column. Sternum & ribs Appendicular skeleton: Bones of the upper limb. Bones of the lower limb Bony skeleton is divided into

Appendicular skeleton: Axial skeleton: Skull and mandible. Vertebral column. Sternum & ribs Appendicular skeleton: Bones of the upper limb. Bones of the lower limb

Skull & mandible

Hyoid bone

Ribs & sternum

Vertebral column

According to the process of ossification

l-Intramembraneous: as Clavicle, Mandible, and skull Cap.

l-Intramembraneous: The bones are developed directly from connective tissue membrane (mesenchyme).

2- Intra-cartilaginous ossification: It occurs in long bones, vertebrae, ribs and base of skull. The connective tissue membrane (mesenchyme) is changed at first into a cartilage model.

Classification of bones according to shape

1- Long bones 2- Short bones 3- Flat bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

1- Long bone Present in upper and lower limbs (appendicular skeleton). Each bone consists of two ends called epiphysis and a shaft in between called diaphysis.

1- Long bone Present in upper and lower limbs (appendicular skeleton). Each bone consists of two ends called epiphysis and a shaft in between called diaphysis.

Carpal bones (in hand) 2- Short bones 1- Long bones 3- Flat bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

Tarsal bones (in foot). 2- Short bones 1- Long bones 3- Flat bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

Scapula 3- Flat bones 1- Long bones 2- Short bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

Sternum 3- Flat bones 1- Long bones 2- Short bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

Skull 3- Flat bones 1- Long bones 2- Short bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

Vertebrae 4- Irregular bones 1- Long bones 2- Short bones 3- Flat bones 4- Irregular bones 5- Pneumatic bones 6- Sesamoid bones

5- pneumatic bone

6- Sesamoid bone (patella)

Bones of upper limb

Bones of upper Bones of the shoulder girdle: Clavicle: anteriorly. Scapula: posteriorly. (ii) Bones of the arm: humerus. (iii) Bones of the forearm: Radius: laterally. Ulna: medially.

Bones of upper (iv) Skeleton of the hand: Carpal bones: in the wrist. Metacarpal bones: in the palm. Phalanges: in the fingers.

Bones of lower limb

Bones of lower limb (i) Bones of the Pelvic girdle: Hip bone. (ii) Bones of the thigh: femur. (iii) Bones of the leg: Fibula: laterally. Tibia: medially.

Bones of lower limb Skeleton of the foot: Tarsal bones: in the foot. Metatarsal bones: in the plantar. Phalanges: in the toes.

Bony skeleton is divided into Axial skeleton: Skull and mandible. Vertebral column. Sternum & ribs Appendicular skeleton: Bones of the upper limb. Bones of the lower limb