humerus anatomy

Structure of the Humerus

The humerus is a long bone making up the upper part of the human arm. It has three main sections: the proximal end, the shaft, and the distal end.The proximal end forms part of the shoulder joint. It features the humeral head which fits into the shoulder socket, the glenoid fossa of the scapula, allowing a wide range of motion. Adjacent to the humeral head, the anatomical neck and the greater and lesser tubercles provide attachment points for the muscles of the rotator cuff.

Moving further down, the shaft of the humerus is roughly cylindrical in shape, though slightly flattened from front to back. It acts mainly as a bridge between the shoulder and elbow joints. Key landmarks here include the deltoid tuberosity, where the deltoid muscle attaches, and the radial groove, which accommodates the passage of the radial nerve.

Finally, the distal end of the humerus articulates with the forearm to form the elbow joint. It houses several important structures:

• The trochlea, which interacts with the ulna.
• The capitulum, which meets the radius.
• The medial and lateral epicondyles, which serve as key spots for ligament and muscle attachment.

Humerus Anatomy Structural Details

Understanding the structural details of the humerus is vital for recognizing its function in the skeletal system. It consists of various segments, each serving specific roles and connections in the arm.

Proximal End of the Humerus

The proximal end of the humerus is integral to shoulder articulation. It includes several key features:

• Humeral Head: This oval section fits into the shoulder’s glenoid fossa, enabling a wide range of motion.
• Anatomical Neck: A narrow area just below the head providing structural transition.
• Greater and Lesser Tubercles: Elevations serving as muscle attachment points, specifically for rotator cuff muscles.

Shaft of the Humerus

The shaft forms the long body of the humerus. It connects the proximal and distal ends while featuring several important landmarks:

• Deltoid Tuberosity: A rough, raised area where the deltoid muscle attaches.
• Radial Groove: A depression accommodating the radial nerve and profunda brachii artery.

Distal End of the Humerus

The distal end of the humerus articulates with the forearm bones to form the elbow joint. Its notable features include:

Proximal Humerus Anatomy

The proximal humerus forms a crucial part of your upper arm anatomy that interfaces with the shoulder. It plays a vital role in the movement and support of the arm.

Humerus Head Anatomy

The humerus head is a large, rounded structure at the top of the humerus bone. It fits into the glenoid cavity of the shoulder blade to form the shoulder joint. This joint allows a great range of motion, enabling you to move your arm in nearly all directions.Here are some important features of the humerus head:

• Anatomical Neck: This is the slight constriction directly below the head, marking the boundaries between the head and the tubercles.
• Greater Tubercle: Located laterally, it provides attachment for several shoulder muscles, essential for arm elevation and rotation.
• Lesser Tubercle: Situated medially, providing attachment for the subscapularis muscle, aiding in the internal rotation of the arm.

Distal Humerus Anatomy

The distal humerus is a key section of the arm's skeletal framework that connects with the forearm. It plays a crucial role in forming the elbow joint and facilitates various arm movements.

Humerus Anatomy Explained

The anatomy of the distal humerus is composed of several essential structures, each responsible for different functionalities of the elbow joint.In the distal region, you find the:

• Trochlea: This spool-shaped structure articulates with the ulna, enabling hinge-like movements in the elbow.
• Capitulum: This rounded region connects with the head of the radius, allowing rotational movements of the forearm.
• Medial and Lateral Epicondyles: Protrusions that provide attachment points for muscles and ligaments contributing to joint stability.