Brachial Plexus Flashcards
N. suprascapularis Arises from?
c6-c7
N. suprascapularis מעצבב ועובר דרך?
The nerve enters the distal end of the intermuscular space between the Mm. supraspinatus and subscapularis from the medial side. It is accompanied by the supraspinous artery and vein. It passes over the
scapular notch, innervates the m. supraspinatus and continues across the neck of the scapula
distal to the end of the spine to enter the m. infraspinatus. Prior to passing distal to the spine the
nerve sends a small branch to the lateral part of the shoulder joint.
Nn. subscapulares Arises from?
Usually a single, but occasionally double, nerve that arises from the union of a branch from the sixth and seventh cervical nerves (c6-c7)
Nn. subscapulares מעצבב ועובר דרך?
It usually divides into cranial and caudal parts on
entering the medial surface of the subscapular muscle, which it supplies. The subscapular nerve is about 5 cm long in a medium sized dog. This permits the extensive sliding movement of the shoulder on the thorax during locomotion without nerve injury.
N. axillaris
This nerve passes from medial to lateral by running between the caudo-ventral edge of the M. subscapularis and the distal M. teres major. It then crosses the flexor surface of the shoulder joint to reach the deep surface of the Pars acromialis of the M. deltoideus. The nerve innervates the true flexors of the shoulder joint (i.e. M. teres major, M. teres minor, and M. deltoideus), and the M. cleidobrachialis (formerly the clavicular part of the deltoid); it also supplies a branch to the shoulder joint capsule.
N. axillaris nerve gives off ?
The axillary nerve gives off a cutaneous branch,
the N. cutaneus antebrachii cranialis.
N. axillaris Arises from?
c6-c8
N. musculocutaneus מעצבב ועובר דרך?
From the brachial plexus, this nerve runs towards the elbow joint on the caudo-medial surface of the M. biceps brachii; it lies cranial to the A. brachialis and the median and ulnar nerves. At the shoulder joint, a small branch is usually given off to the M. coracobrachialis. A little farther distally, the nerve gives off the R. muscularis proximalis to the M. biceps brachii. Just proximal to the elbow, the musculocutaneus nerve gives off a communicating branch to the N. medianus; this R. communicans usually lies on the medial surface of the brachial artery.
Distal to the R. communicans the nerve gives off the R. muscularis distalis to the M. brachialis and a small branch to the elbow joint:
N. musculocutaneus terminates as the?
it terminates as the N. cutaneus antebrachii medialis.
N. musculocutaneus gives off 3 branches..who are them?
R. muscularis proximalis R. communicans R. muscularis distalis
N. musculocutaneus Arises from?
c6-c8
N. radialis Arises from?
c6-t2
N. radialis מעצבב ועובר דרך?
The N. radialis is a vitally important nerve as it innervates all the extensors of the elbow, carpus, and digits. After leaving the brachial plexus, this large nerve runs over the tendinous insertion of the M. latissimus dorsi and dips between the medial and long heads of the triceps. It then continues disto-laterally on the caudal and lateral surfaces of the M. brachialis. Branches are supplied to the M. tensor fasciae antebrachii, M. triceps brachii (all four heads) and M. anconeus
N. radialis divides into..?were?
Beneath the distal margin of the lateral head of the triceps, it divides into superficial
and deep branches:R. superficialis R. profundus
R. superficialis
The superficial branch appears at the cranio-ventral edge of the triceps’ lateral head and divides into a larger R. lateralis and a smaller R. medialis. The lateral branch gives off the N. cutaneus antebrachii lateralis to the lateral aspect of the elbow and proximal antebrachium.
The lateral and medial branches then run distally flanking the V. cephalica and the slender lateral and medial branches of the A. antebrachialis superficialis cranialis; they innervate the skin on the cranio-lateral, cranial and cranio-medial aspects of the antebrachium.
R. profundus
The deep branch runs beneath the M. extensor carpi radialis, across the flexor surface of
the elbow and reaches the deep lateral aspect of the antebrachium by passing under the M.
supinator. It innervates all the extensors of the carpus and the digits (including the M. extensor
carpi ulnaris / M. ulnaris lateralis), the M. brachioradialis, M. supinator and M. abductor digiti I
longus; it also supplies a small branch to the elbow joint capsule.
N. medianus
The N. medianus and N. ulnaris innervate all the flexors of the carpus and digits. The median nerve is initially bound to the N. ulnaris by fascia. The nerves separate in the proximal
brachium but remain adjacent to each other; the median nerve lies caudal to the brachial artery
and cranial to the ulnar nerve. Just proximal to the elbow the median nerve receives the R. communicans from the N. musculocutaneus. Distal to the elbow, it passes beneath the M. pronator teres and, with the A. mediana, runs between the superficial and the deep digital
flexors. Branches are supplied to the M. pronator teres, M. pronator quadratus, M. flexor carpi radialis, M. flexor digitorum superficialis, parts of the deep digital flexor and elbow joint
capsule.
N. ulnaris
The ulnar and median nerves innervate all the flexors of the carpus and digits. Initially,
the N. ulnaris is bound to the median nerve by fascia. The nerves separate in the proximal
brachium but remain adjacent to each other; the ulnar nerve lies caudal to the median nerve. In
the mid-brachium, the ulnar nerve gives off a cutaneous branch, the N. cutaneus antebrachii
caudalis. This branch runs over the medial aspect of the olecranon and innervates the skin of the
caudal antebrachium.
The N. ulnaris continues distally (accompanied the A. collateralis ulnaris) over the
medial epicondyle of the humerus, and runs between the superficial digital flexor and M. flexor
carpi ulnaris Caput ulnare. Branches are supplied to the M. flexor carpi ulnaris and parts of the
deep digital flexor; a small branch is also supplied to the elbow joint capsule. The nerve
descends on the caudal surface of the deep digital flexor, covered by the humeral head of the M.
flexor carpi ulnaris. Proximal to the carpus a R. dorsalis is given off, and the N. ulnaris
continues as the R. palmaris.
N. medianus Arises from?
c7-t1
N. ulnaris Arises from?
c8-t2
