In the palm of the

hand A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala (which has two opposable thumbs on each "h ...

the

median nerve The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus. The median nerve originates from the lateral and medial cords of the brachial plexus, and has contr ...

is covered by the skin and the

palmar aponeurosis The palmar aponeurosis (palmar fascia) invests the muscles of the palm, and consists of central, lateral, and medial portions. Structure The central portion occupies the middle of the palm, is triangular in shape, and of great strength Its apex i ...

, and rests on the tendons of the

flexor muscles Anatomical terminology is a form of scientific terminology used by anatomists, zoologists, and health professionals such as doctors. Anatomical terminology uses many unique terms, suffixes, and prefixes deriving from Ancient Greek and Latin. The ...

. Immediately after emerging from under the

transverse carpal ligament The flexor retinaculum (transverse carpal ligament, or anterior annular ligament) is a fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones of the hands, covering them and forming the carpal tunnel. Structur ...

the

becomes enlarged and flattened and splits into a smaller, lateral, and a larger, medial portion. The ''lateral portion'' supplies a short, stout branch to certain of the muscles of the ball of the

thumb The thumb is the first digit of the hand, next to the index finger. When a person is standing in the medical anatomical position (where the palm is facing to the front), the thumb is the outermost digit. The Medical Latin English noun for thumb ...

, viz., the

abductor pollicis brevis The abductor pollicis brevis is a muscle in the hand that functions as an abductor of the thumb. Structure The abductor pollicis brevis is a flat, thin muscle located just under the skin. It is a thenar muscle, and therefore contributes to the ...

, the

opponens pollicis The opponens pollicis is a small, triangular muscle in the hand, which functions to oppose the thumb. It is one of the three thenar muscles. It lies deep to the abductor pollicis brevis and lateral to the flexor pollicis brevis. Structure The opp ...

, and the superficial head of the flexor brevis, and then divides into three proper palmar digital nerves of median nerve (proper volar digital nerves): * two of these supply the sides of the thumb, * while the third gives a twig to the first lumbricalis and is distributed to the radial side of the index finger. It also divides into two common palmar digital nerves: * The first of these divides into two proper digital nerves for the adjoining sides of the

index Index (or its plural form indices) may refer to: Arts, entertainment, and media Fictional entities * Index (''A Certain Magical Index''), a character in the light novel series ''A Certain Magical Index'' * The Index, an item on a Halo megastru ...

and

middle finger The middle finger, long finger, second finger, third finger, toll finger or tall man is the third digit of the human hand, located between the index finger and the ring finger. It is typically the longest digit. In anatomy, it is also called ...

s; * the second common palmar digital nerve splits into two proper digital nerves for the adjoining sides of the third and fourth digits. Each proper digital nerve, opposite the base of the first phalanx, gives off a dorsal branch which joins the dorsal digital nerve from the

superficial branch of the radial nerve The superficial branch of the radial nerve passes along the front of the radial side of the forearm to the commencement of its lower third. It is a sensory nerve. It lies at first slightly lateral to the radial artery, concealed beneath the Brac ...

, and supplies the

integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, shell, germ or rind. Etymology The term is derived from ''integumentum'', which is Latin for "a covering". In a transferred, or ...

on the dorsal aspect of the last phalanx. At the end of the digit, the proper digital nerve divides into two branches, * one of which supplies the pulp of the finger, * the other ramifies around and beneath the nail. The proper digital nerves, as they run along the fingers, are placed superficial to the corresponding arteries.

Additional images

File:Gray425.png, The palmar aponeurosis. File:Gray811and813.PNG, Cutaneous nerves of right upper extremity. File:Gray812and814.PNG, Diagram of segmental distribution of the cutaneous nerves of the right upper extremity. File:Slide5gggg.JPG, Proper palmar digital nerves of median nerve

References

External links

* {{Authority control Nerves of the upper limb

See also

Additional images

References

External links