User:Aryanraghu/NERVE SUPPLY OF HAND

NERVES ENTERING HAND
1.Median nerve:Root value-Lateral cord(C5,C6,C7) and Medial cord(C8,T1).
 * Anterior of hand-

2.Ulnar Nerve:Root value-Medial cord-C8,T1.

1.Ulnar Nerve:Root value-C8,T1.
 * Posterior of hand-

2.Radial Nerve:Root value-C5,C6,C7,C8,T1.

Definition and function
Part of upper limb distal to forearm.It includes wrist,palm and phalanges. Hand has evolved with diverse fine and coarse movements due to large number of small and large muscles and all are finely regulated by nerve supply from 4 nerves named above.

Evolution
The prehensile hands and feet of primates evolved from the mobile hands of semi-arboreal tree shrews that lived about a. This development has been accompanied by important changes in the brain and the relocation of the eyes to the front of the face, together allowing the muscle control and stereoscopic vision necessary for controlled grasping. This grasping, also known as power grip, is supplemented by the precision grip between the thumb and the distal finger pads made possible by the opposable thumbs.

CUTANEOUS SUPPLY OF HAND

 * Anterior:
 * 1) Palmer Cutaneous Branch Of Median nerve-Lateral part of skin of palm over thenar eminence and distal to it.
 * 2) Palmer Cutaneous Branch Of Ulnar Nerve-Medial part of skin over hypothenar eminence and distal to it.
 * Posterior:
 * 1) Dorsal Branch Of Ulnar Nerve-Medial part of skin of dorsum of hand(except nails).
 * 2) Superficial branch of Radial Nerve-lateral part of skin of dorsum of hand(Except nails).

MUSCULAR SUPPLY
Lateral branch supplies-
 * Median Nerve:It enters hand below flexor retinaculum and divides into lateral and medial branches.

1.Thenar Muscles-Abductor Pollices Brevis,Flexor Pollices Brevis and Opponens Pollices by a muscular recurrent branch.

2.One proper digital branch to radial side of index finger.

3.Branches to thumb.

Medial branch gives 2 common digital branches which supply middle finger and radial side of ring finger and ulnar side of index finger.

Superficial Branch supplies superficial muscle of palm-Palmaris Brevis.This muscle holds skin tightly to underlying deep fascia.Palmaris Brevis originates from flexor retinaculum and inserted on to palmar skin.
 * Ulnar Nerve:It enters hand superficial to flexor retinaculum along with ulnar artery which is lateral to nerve.Ulnar nerve passes lateral to pisciform bone and then it divides into two branches -superficial and deep.

Deep Branch goes along with deep branch of ulnar artery supplying intrinsic muscles of hand.It lies proximal to Deep Palmar Arch of palm.Deep Branch supplies :

1.Hypothenar Muscles:Abductor Digiti Minimi,Flexor Digiti Minimi,Opponens Digiti Minimi.

2.3rd and 4th lumbricals.

3.All 4 Palmar interossei.

4.All 4 dorsal Interossei

5.Deep branch of ulnar nerve terminates by supplying Adductor Pollices Brevis.


 * Radial Nerve gives cutaneous supply only.It does not give branches to any muscles of hand.Though it gives nerve supply to Extensor muscles of forearm.

CREATED BY
Raghunandan Dixit,AIIMS,NEW DELHI.