Hand anatomy, nerves, spine relationship

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Hand anatomy, nerves, spine relationship

Postby misterjuanperalta on January 22nd, 2015, 6:17 pm

The hand is innervated by 3 nerves: the median, ulnar, and radial. Each has sensory and motor components. Variations from the classic nerve distribution are so common that they are the rule rather than the exception. The skin of the forearm is innervated medially by the medial antebrachial cutaneous nerve and laterally by the lateral antebrachial cutaneous nerve.

The median nerve is responsible for innervating the muscles involved in the fine precision and pinch function of the hand. It originates from the lateral and medial cords of the brachial plexus (C5-T1). In the forearm, the motor branches supply the pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis muscles. The anterior interosseus branch innervates the flexor pollicis longus, flexor digitorum profundus (index and long finger), and pronator quadratus muscles.

Proximal to the wrist, the palmar cutaneous branch provides sensation at the thenar eminence. As the median nerve passes through the carpal tunnel, the recurrent motor branch innervates the thenar muscles (abductor pollicis brevis, opponens pollicis, and superficial head of flexor pollicis brevis). It also innervates the index and long finger lumbrical muscles. Sensory digital branches provide sensation to the thumb, index, long, and radial side of the ring finger.

The ulnar nerve is responsible for innervating the muscles involved in the power grasping function of the hand. It originates at the medial cord of the brachial plexus (C8-T1). Motor branches innervate the flexor carpi ulnaris and flexor digitorum profundus muscles to the ring and small fingers. Proximal to the wrist, the palmar cutaneous branch provides sensation at the hypothenar eminence. The dorsal branch, which branches from the main trunk at the distal forearm, provides sensation to the ulnar portion of the dorsum of the hand and small finger, and part of the ring finger.

At the hand, the superficial branch forms the digital nerves, which provide sensation at the small finger and ulnar aspect of the ring finger. The deep motor branch passes through the Guyon canal in company with the ulnar artery. It innervates the hypothenar muscles (abductor digiti minimi, opponens digiti minimi, flexor digiti minimi, and palmaris brevis), all interossei, the 2 ulnar lumbricals, the adductor pollicis, and the deep head of the flexor pollicis brevis.

The radial nerve is responsible for innervating the wrist extensors, which control the position of the hand and stabilize the fixed unit. It originates from the posterior cord of the brachial plexus (C6-8). At the elbow, motor branches innervate the brachioradialis and extensor carpi radialis longus muscles.

At the proximal forearm, the radial nerve divides into the superficial and deep branches. The deep posterior interosseous branch innervates all the muscles in the extensor compartment: supinator, extensor carpi radialis brevis, extensor digitorum communis, extensor digiti minimi, extensor carpi ulnaris, extensor indicis proprius, extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus.

The superficial branch provides sensation at the radial aspect of the dorsum of the hand, the dorsum of the thumb, and the dorsum of the index finger, long finger, and radial half of the ring finger proximal to the distal interphalangeal joints.

Source: http://emedicine.medscape.com/article/1 ... #aw2aab6b7
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Re: Hand anatomy, nerves, spine relationship

Postby elliottok on February 11th, 2015, 5:05 pm

Spam. Please stop.
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Re: Hand anatomy, nerves, spine relationship

Postby garym on February 13th, 2015, 8:55 am

elliottok wrote:Spam. Please stop.


I don't see spam here. Found the information interesting.
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Re: Hand anatomy, nerves, spine relationship

Postby Yuliasir on February 13th, 2015, 9:24 am

garym wrote:
elliottok wrote:Spam. Please stop.


I don't see spam here. Found the information interesting.



Me too by the way. Way to much of our fellows have a very little idea about what muscles and nerves we have in our body and how they are realted to each other, therefore too much of perveived issues are considered as dangerous etc. So as far as long the links provided by mrjuanperalta doe net lead to any viral infected sites, or do not imply bying something unnencessary or doubtful, they might be useful.
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