From Academic Kids
The finger is any of the digits of the hand in humans and other species such as the great apes. The grace of the fingers is not sacrificed to their dexterity due to the placement of their muscles in the forearm, with motion communicated via long tendons which may be observed on the back of the hand. A notable exception is the thumb, with its flexor and rotators comprised in the hand itself.
The bones of the fingers are called phalanges (singular phalanx); the thumb has two phalanges, and the other fingers have three. The fingers' names in English are shown below, from the most radial to the most ulnar:
- index finger, pointer finger, or forefinger
- middle finger or long finger
- ring finger
- little finger or pinky finger
In anatomy, the thumb is the first finger and the little finger is the fifth finger. Thus the third finger means the middle finger in anatomy, not the ring finger as in daily English.
Relative to much of the skin of the human body, the fingertips have a high concentration of nerve endings, equipping them as centers of tactile sensation; touching something or someone is often done with the hands and in particular the fingers.
Another important example of this capacity is in the ability to read Braille. Additionally, prehension is enhanced by the presence of the ridges and whorls known as fingerprints. Each finger is protected at its dorsal terminus by a fingernail (Latin unguis, unguiculus).
In young children, the fingertip is one of the few tissues in the human body capable of full regeneration, although this ability disappears after about age 6.  (http://www.straightdope.com/mailbag/mnewlimb.html)