C20 Flashcards
Brachial plexus
Main nerves of the brachial plexus
- N. thoracicus longus
- N. thoracodorsalis
- N. thoracicus lateralis
- Nn. Pectorales craniales et caudales
- Nn. subscapulare
- N. suprascapularis
- N. musculocutaneus
- N. axillaris
- N. radialis
- N. medianus
- N. ulnaris
N. thoracicus longus
Passes caudally on the lateral surface of the thoracic part of the ventral serratus muscle.
innervates M. serratus ventralis
N. thoracodorsalis
Arises from the last cervical spinal nerve, runs caudally
Crosses M. teres major toward the latissimus dorsi
Innervates: M. latissimus dorsi
N. thoracicus lateralis
arises from the caudal part of the plexus (c8 and Th1)
some of the branches unites with the intercostal nerves
innervates: skin caudal to tricep and over ventral thorax and abdomen ( abdomnial part of the cutaneous muscle)
Nn. pectroalis cranialis et caudalis
Cranial part of the plexus
Innervates: pectoral muscles
Cranial: M. pectoralis superficilais
Un: M. subclavia
Caudal: M. pectoralis profundus
Nn. subscapularis
Can either rise as a separate nerve or as a plxus from the crnail part of the brachial plexus
Innervates: cranial and middle part of the subscapular muscle
N. suprascapularis
enters between the subscapular and suprascapular muscle
runs to the lateral side of the scapula
close relation to the bone, makes it vulnerable to traumatic damage (shoulder slip, sweeny in horses)
Innervates: M. supraspinatus and M. infraspinatus
N. musculocutaneous
Arises caudal to the suprascapular nerve
runs paralell with the median nerve with which it communicates
- In Un: forms a loop around the axillary, ansa Axillaris
- In Ca: closer to the elbow joint, r- communicans
Branches to become
- Proximal muscular branch, innervating: coracobrachialis and bicep
- median nerve, innervating: brachial muscle, skin on the medial aspect of antebrachia
N. axillaris
passes caudal to the shoulder joint to the lateral aspect of the limb
Innervates:
on the medial side: teres major, caudal third of subscapular muscle, joint capsule and teres minor
On the lateral side: deltoideus and cleidobracialis
cutaneus branch: innervating the skin on the cranial aspect of the arm and antebrachium
the branch to the cleidobrachial muscle is also considered an independent branch of the plexus, and is also termed the axillaris accesorius
N. radialis
recieves its fibers fromt he 8th cervical nerve mostly
largest nerve of the brachial plexus, with the widest dirstribution
extends all the way down to the phalanxes and to the distal end of the carpus in the horse
Innervates: all extensor muscles of the thoracic limb - the shoulder joint
- Tricep
- TFA
- Anconeus
- skin on the lateral aspect - r.cutaneus antebrachia
- All extensors of carpus and digits
N. mediana
runs down the meidal surface of the antebrachiumit is connected to the musculocutaneus nerve
at the cranial aspect the median nerve passes laterally under the pronator muscle to innervate the large caudal group of the flexors the antebrachia
passes through the supracondylar foramen in the cat
Innervates
- M. flexor radialis
- pronator teres
- pronator quadratus
- DDF
- SDF - radial and humeral head
N. ulnaris
Runs on the medial aspect of the antebrachia
passes caudally at the level of the elbow joint
runs under the ulnar head of the ulnar flexor muscle to the ulnar groove on the caudal aspect of the antebrachium
It passes through the carpal canal
- n. cutaneus antebrachia caudale - sensory
- r. dorsalis - proximal to the accessory carpal bone - innervates the skin on the lateral surface of the limb
innervates
- M. flexor carpi ulnaris
- m. flexor digitalis superficialis
- m. flexor digitalis profundus - ulnar and humerla head
- interosseus muscles
