Which artery supplies blood specifically to the forearm, wrist, and thumb?

The radial artery is primarily responsible for supplying blood to the forearm, wrist, and thumb. As it extends down the forearm, it runs along the radial side (thumb side) and gives off several branches that provide blood to the muscles and tissues in that region. This direct distribution makes the radial artery crucial for maintaining proper blood flow to these specific areas.

In contrast, the ulnar artery, while also supplying parts of the forearm and hand, predominantly services the structures on the ulnar side (the side opposite the thumb) of the forearm and is more involved with the little finger and surrounding structures. The femoral artery, located in the thigh, supplies blood to the lower limb more generally, not specifically to the forearm or hand. The brachial artery primarily supplies the upper arm and branches into the radial and ulnar arteries in the elbow area. Thus, the specificity of the radial artery's supply to the forearm, wrist, and thumb distinguishes it as the correct choice in this context.