Appendicular Skeleton

The skeleton which is present in the lateral side of a body is called appendicular skeleton.

Bones of upper extremity

Pictorial girdle:

Pictorial girdle is also called shoulder girdle. It provides articulation to the arm bones and surface for the attachment of tendons of biceps and triceps muscle of the upper arm.

Forelimbs:

There are 60 bones in the forelimbs having 30 bones in each limb. The bones of the forelimbs are as follows:

Humerus: Humerus is situated in the upper arm and one in each limb. It is long bone consisting rounded head, rod like shaft and hinglike the lower end.

Radius and ulna: Radius and ulna are 2 bones of the forearm of each limb. Radius lies on the inner side while ulna lies towards the little finger. Ulna is larger in size than the radius. Radius and ulna articulate with the humerus at the elbow joint and carpels at the wrist joint.

Carpels: Carpels are 8 in number in each limb and arranged in two rows of four each. They are fitted together and held in position by the ligaments.

Metacarpals: Metacarpals are 5 in number in each limb and form the palm.

Phalanges: The phalanges are 14 in number in each limb, 3 in a finger and 2 in a thumb.

Bones of lower extremity

Pelvic girdle:

Pelvic girdle is located in the lower part of the trunk. It supports and protects the abdomen, urinary bladder, reproductive organs etc. It lowers the center of gravity and helps in the erect posture. The shape of the female pelvis protects the baby in the uterus and also allows for the passage of the baby during birth.

Hind limb:

There are 60 bones in hind limbs i.e. 30 bones in each. These bones provide strength to the legs to support body weight and help in locomotion. It consists of following bones,

Femur or thigh bone: The femur is the longest and strongest bone in the body. Its inner portion consists spongy bone.

Patella or knee cap: Patella is one in each leg which provides additional joint. It is small, flat and triangular bone.

Tibia and fibula: Tibia and fibula are the two bones of each leg. Tibia is also known as shin bone with large upper end and articulates with the femur. Lower ends articulates with the ankle bones. Similarly, the fibula is a long slender and weak bone that is situated on the outer side of the tibia.

Tarsals: Tarsals are 7 in each leg and they form posterior part of the foot called ankle.

Metatarsals: Metatarsals are 5 in each leg and form a larger part of the foot. They articulate with tarsal and phalanges.

Phalanges: Phalanges are 14 in each leg i.e. 2 in the big toe and 3 in each of the other toe.