Humerus
It is the bone found in the upper arm,
Its head articulates with the scapula at the glenoid cavity of the pectoral girdle where it forms a ball and socket joint.
Near the head are two roughened projections, the greater and lesser tuberosities.
These extend into a shaft which provides surface for muscle attachment.
Between the tuberosities is a groove.
It is along this groove than the tendon of the biceps muscles passes.
At the lower end is the trochlea which articulates with the forearm to form a hinge joint at the elbow.
umerus