Which bone is the upper arm bone?

Which bone is the upper arm bone?

• A. Scapula
• B. Humerus
• C. Ulna
• D. Radius

Answer: (B)

The upper arm bone is the humerus. It’s the long bone that runs from the shoulder joint down to the elbow, forming the main support of the upper limb. At the shoulder, its rounded proximal end (the head) fits into the glenoid cavity of the scapula to make the shoulder joint. At the elbow, its distal end interacts with the forearm bones—the ulna and radius—through the elbow joint. The scapula is the shoulder blade and part of the shoulder girdle, while the ulna and radius are the bones of the forearm, not the upper arm.

The upper arm bone is the humerus. It’s the long bone that runs from the shoulder joint down to the elbow, forming the main support of the upper limb. At the shoulder, its rounded proximal end (the head) fits into the glenoid cavity of the scapula to make the shoulder joint. At the elbow, its distal end interacts with the forearm bones—the ulna and radius—through the elbow joint. The scapula is the shoulder blade and part of the shoulder girdle, while the ulna and radius are the bones of the forearm, not the upper arm.