Appendicular skeleton: It consists of 2 parts-the girdles and the limbs.
(i) Pectoral girdle: It is called shoulder girdle. It is formed of the two bones: (a) Clavicle and (b) Scapula
(a) Clavicle: It is a small 'S shaped collar bone. lt lies on the anterio-lateral side of the thoracic basket. On outside, it articulates with the sternum. It articulates with the scapula on other end. It is called collar bone.
(b) Scapula: A large dorsoventrally flattened triangular bone having club-shaped spine is called shoulder blade. A glenoid cavity fits the head of humerus. There is an acromion process articulating with the clavicle.
Fore limb: It consists of thirty bones.
(a) The upper arm has humerus. It is a straight bone with a long shaft.
(b) The lower end of humerus articulates with the radius-ulna. Deltoid ridge is the characteristic feature of this bone.
(c) Radius is slightly shorter than ulna.
(d) The lower end of it articulates with the carpal of wrist. Carpals (wrist bones) are eight.
(e) Metacarpals are five.
(f) Phalanges are three bones in each finger.
Digital formula of phalanges: 2,3,3,3,4
(i) Pelvic girdle: It consists of two halves. Each is called innominate which has three bones:
(a) ilium,
(b) ischium, and
(c) pubis.
They unite in the centre to form acetabulum. Two hip bones make arch behind by uniting with the sacrum and the coccyx.
Hind limb: It consists of 30 bones.
(a) Femur is thigh bone. It is longest bone of the body.
(b) The patella forms knee cap (patella).
(c) Two bones lie in the shank region of the leg:
(i) tibia and
(ii) fibula.
(d) Seven tarsal bones make ankle.
(e) The foot possesses 7 tarsals.
(f) Metatarsals are five in number.
(g) And Phalanges are 14 in number.
