Anatomy of the Upper Limb Bones

A concise overview of the key anatomical features, articulations, muscle attachments, and clinical significance of the Humerus, Hip Bone, Scapula, and Clavicle for quick revision.

Core Principles

• Humerus: The long bone of the arm, articulating with the scapula at the shoulder and the radius/ulna at the elbow. Key features include the surgical neck (common fracture site) and radial groove.
• Hip Bone (Os Coxae): An irregular bone formed by the fusion of ilium, ischium, and pubis, forming the pelvic girdle. The acetabulum is its key feature for the hip joint.
• Scapula: A flat, triangular bone on the posterior thorax, connecting the upper limb to the trunk. It features the glenoid cavity for the humerus and the acromion for the clavicle.
• Clavicle: A modified long bone acting as a strut between the sternum and scapula. It's the first bone to ossify and the last to fuse, with its mid-shaft being a common fracture site.
• Articulations: Understanding how these bones connect (shoulder, elbow, hip, knee joints) is crucial for function and clinical assessment.
• Clinical Significance: Knowledge of common fracture sites and associated nerve/vessel injuries is vital for diagnosis and treatment.

Key Terms

• Humerus: The long bone of the upper arm.
• Os Coxae: The hip bone, formed by ilium, ischium, and pubis.
• Scapula: The shoulder blade.
• Clavicle: The collarbone.
• Acetabulum: The socket in the hip bone that receives the head of the femur.
• Glenoid Cavity: The socket in the scapula that receives the head of the humerus.
• Surgical Neck: A common fracture site on the humerus, near the axillary nerve.
• Linea Aspera: A roughened ridge on the posterior aspect of the femur shaft for muscle attachment.

Quiz

• Which nerve is commonly injured with a fracture of the humerus at the surgical neck?: Axillary Nerve
• The acetabulum, the socket for the hip joint, is formed by the fusion of which three bones?: Ilium, Ischium, Pubis
• Which bone is known as the 'collarbone' and acts as a strut between the sternum and scapula?: Clavicle