The humerus is a long bone located in the upper arm, extending from the shoulder to the elbow. It is the largest and strongest bone in the upper limb and serves as a crucial component of the skeletal system. Structurally, the humerus consists of a proximal end, a shaft, and a distal end.
The proximal end of the humerus connects to the shoulder joint, comprising specific features like the humeral head, anatomical and surgical necks, and various tuberosities. The humeral head forms a ball-like structure, articulating with the glenoid cavity of the scapula to form the shoulder joint.
The shaft of the humerus is long and curved, providing support and stability to the upper arm. Numerous prominent muscle attachments are found along the shaft, facilitating movement and range of motion of the arm. Towards the distal end, the humerus widens to form the capitulum and trochlea, which articulate with the bones of the forearm (radius and ulna) to create the elbow joint.
The humerus plays a crucial role in various upper limb movements, including flexion, extension, rotation, and adduction. It also serves as a site for many muscle attachments, allowing for the attachment and action of different muscles that control arm movements.
In summary, the humerus is the largest bone in the upper extremity, connecting the shoulder and the elbow joints. Its structural features include a proximal end connecting to the shoulder joint, a long and curved shaft, and a distal end articulating with the forearm bones. It is essential for providing stability and facilitating a wide range of upper limb movements.
