Radial nerve
The radial nerve (Abbr. Radial nerve ) or spokes nerve is a nerve of the Armnervengeflechts (brachial plexus). It has its origin in humans in the posterior fasciculus of the brachial plexus and thus draws fibers from the spinal cord segments C5-Th1, in domestic mammals from C7-Th1, in predators also from Th2. It innervates the extensor muscles of the elbow , wrist and finger (in animals the front toe) joints .
course
In the middle of the upper arm, the radial nerve runs between the heads (caput laterale and caput mediale) of the musculus triceps brachii and, lying directly on the humerus , turns outwards (laterally) together with the deep artery brachii in the radial canal and runs over the elbow . There it divides into a ramus superficialis (skin branch) and a ramus profundus (muscle branch). The ramus profundus breaks through the supinator muscle .
Innervated muscles
The radial nerve innervates the following muscles on the upper arm:
In animals, the nerve also innervates the tensor fasciae antebrachii muscle ; in ungulates , a branch also attaches to the brachialis muscle .
It supplies the following muscles on the forearm:
- Extensor carpi radialis longus and brevis muscles
- Musculus extensor digitorum (in animals, Musculus extensor digitorum communis )
- Musculus extensor digiti minimi (animals: Musculus extensor digitorum lateralis )
- Extensor carpi ulnaris muscle
- Extensor indicis muscle
- Abductor pollicis longus muscle
- Extensor pollicis longus and brevis muscles
- Brachioradialis muscle (absent in ungulates)
- Supinator muscle
- short finger extensors
Treated skin areas
The radial nerve supplies sensitively
- the lateral lower upper arm (N. cutaneus brachii lateralis inferior)
- the extensor side of the forearm (N. cutaneus antebrachii posterior)
- the back of the hand (in animals the forefoot) (ramus superficialis)
Radial paralysis
A radial paralysis occurs mainly due to the damaged nerves in the area on the upper arm where the nerve is applied directly to the bone. In this case, the wrist extensors and the extensors of the finger or, in animals, the front toe joints are paralyzed . Due to the relatively higher tone of the intact flexor muscles, the fingers are bent, as is the carpal joint (wrist). In humans, this is referred to as falling hand or kissing hand (similar to the posture when kissing the hand ), in animals as " killing over ".
See also
literature
- Martin Trepel: Neuroanatomy. Structure and function. 3rd revised edition. Urban & Fischer, Munich et al. 2004, ISBN 3-437-41297-3 .
- Franz-Viktor Salomon: nervous system, systema nervosum. In: Franz-Viktor Salomon, Hans Geyer, Uwe Gille (Ed.): Anatomy for veterinary medicine. Enke, Stuttgart 2004, ISBN 3-8304-1007-7 , pp. 464-577.