Answer
Each upper limb is divisible into four segments; these are brachium, antebrachium, carpus and manus.
1. Brachium. The brachium is the part of the limb that extends from shoulder to elbow. It contains one large bone-- the humerus.
2. Antebrachium is another name for the forearm. It extends from the elbow to to the wrist and contains two bones the ulna ( the larger bone) and the radius ( the smaller bone).
3. The carpus is the wrist. It contains eight bones in two rows-- proximal and distal.
Proximal row: Naming from the thumb side these are scaphoid, lunate, triquetrum, and pisiform
The distal row comprises the trapezium, trapezoid, capitate and lunate.
Note: The flexor retinaculum covers the carpal tunnel.
Work Step by Step
4. The Manus. Manus is Latin for hand. There 19 bones in the hand-- 5 carpal bones in the palm and 14 metacarpals in the fingers. The metcarpals are numbered I-V, with I at the base of the thumb (pollex) and V at the base of the little finger. Each of four fingers has three phalanges bone , but the thumb has only two. The phalanges (singular phalanx) are usually identified by Roman numerals (I, II, III, IV, V) preceded by the adjectives proximal, middle and distal. Thus, taking the pollex as digit I, proximal phalanx I would be the bone in the first segment of the thumb. The right distal phalanx II would be the bone in the last segment of the finger most right-handed people use for pointing.
