The index finger is the second digit of the hand. Along with the thumb and middle finger, it is one of the most often-used digits. The finger has practical applications of both sensory touch and grasp, but it is often used for expressive purposes as well. This usually takes the form of non-verbal hand gestures. For this reason, the index finger is also known as the pointer. The finger is comprised of three phalanges extending from the hand's second metacarpal. The proximate phalange provides the base of the finger, which connects to the intermediate phalange via the knuckle joint. At the end of the finger, the distal phalange provides support to the sensitive pulp of the fingertip. The extensor indicis extends the index finger, while the palmar interosseus adducts it. Oxygenated blood arrives at the finger through the common palmar artery, which extends off of the palmar arch connecting the ulnar and radial arteries. The medial nerve innervates the finger's skin.
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In Depth: Index finger