The upper limb is the part of the appendicular skeleton and has 30 bones in which, the humerus in the arm, the ulna, and radius in the forearm, the 8 carpals in the wrist, the 5 metacarpals in the palm, and the 14 phalanges in the hand.
Here we see the structure of humerus-
-It is the longest and largest bone of the upper limb.
-Below to the head is the neck, and the greater tubercle is a lateral projection distal to the neck, the lesser tubercle projects anteriorly.
-Between these 2 tubercles, there is a groove, the intertubercular sulcus.
-The body of the humerus is cylindrical at the proximal end and becomes triangular, flat and broad at its distal end.
-Laterally, at the middle portion of the shaft, is the deltoid tuberosity, a point of attachment for the deltoid muscle.
-The capitulum is a rounded knob on the distal lateral aspect of the bone that articulates with the head of the radius.
-The radial fossa is an anterior depression above the capitulum.
-The trochlea is in the medial aspect, that articulates with the trochlear notch of the ulna.
-There is a medial and lateral epicondyle, these are rough projections on either side of the distal end of the humerus, which provide an area for the attachment of muscles of the forearm.