Which bone is the upper arm bone?

Which bone is the upper arm bone?

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

Answer: (B)

The upper arm bone is the humerus. It is the long bone that runs from the shoulder to the elbow, forming the main framework of the arm. The humerus has a rounded head that fits into the shoulder socket (glenoid cavity of the scapula) to make the shoulder joint, and its lower end interacts with the forearm bones at the elbow. The radius and ulna are the two bones of the forearm, extending from the elbow to the wrist, not the upper arm. The scapula is the shoulder blade, a flat bone that contributes to the shoulder girdle and does not run along the arm itself.

The upper arm bone is the humerus. It is the long bone that runs from the shoulder to the elbow, forming the main framework of the arm. The humerus has a rounded head that fits into the shoulder socket (glenoid cavity of the scapula) to make the shoulder joint, and its lower end interacts with the forearm bones at the elbow. The radius and ulna are the two bones of the forearm, extending from the elbow to the wrist, not the upper arm. The scapula is the shoulder blade, a flat bone that contributes to the shoulder girdle and does not run along the arm itself.