Final answer:
The extensor carpi radialis longus muscle extends and abducts the wrist, inserts on the base of the second metacarpal, is innervated by the radial nerve, and has its blood supply from the radial artery.
Step-by-step explanation:
The extensor carpi radialis longus is a muscle of the forearm that participates in extending and abducting the wrist. Its insertion is on the base of the second metacarpal bone, allowing it to effectively extend and abduct the hand at the wrist joint.
As part of the superficial posterior compartment of the forearm, it works alongside other extensors, like the extensor carpi radialis brevis and the extensor digitorum. This muscle is innervated by the radial nerve. The blood supply for the extensor carpi radialis longus comes from the radial artery. This setup enables the muscle to assist in stabilizing the hand during finger flexion and wrist extension movements.