The anatomical neck of the humerus is obliquely directed, forming an obtuse angle with the body of the humerus. It represents the fused epiphyseal plate.
It gives attachment to the capsular ligament of the shoulder joint except at the upper inferior-medial aspects
It is best marked in the lower half of its circumference; in the upper half it is represented by a narrow groove separating the head of the humerus from the two tubercles, the greater tubercle and the lesser tubercle.
It affords attachment to the articular capsule of the shoulder-joint, and is perforated by numerous vascular foramina.