Vessels & Nerves Of The Thoracic Limb Flashcards
(25 cards)
The brachial plexus is usually formed by the ventral branches of the..
6th, 7th, & 8th cervical spinal nerves and the 1st & 2nd thoracic spinal nerves
The brachial plexus gives origin to the nerves that innervate the muscles and skin of the…
Thoracic limb, parts of the shoulder girdle musculature and the lateral wall of the thorax and abdomen.
What are some exception in regards to the brachial plexus origin?
The brachiocephalic, omotransverse, rhomboid, & trapezius muscles and the skin over the upper shoulder region - supplied by the dorsal and ventral branches of the cervical and thoracic spinal nerves
Brachial plexus branches are usually mixed:
The cerebrospinal fibers are joined by autonomous fibers from the stellate ganglion.
The brachial plexus is located:
Cranial to the first rib between the long muscle of the neck and the scaleni muscles
Where do the roots of the brachial plexus reach?
The medial aspect of the shoulder
The branches of the brachial plexus include:
-long thoracic nerve (n. thoracicus longus)
-thoracodorsal nerve (n. thoracodorsalis)
-lateral thoracic nerve (n. thoracicus lateralis)
-cranial and caudal pectoral nerves (nn. pectorales craniales and caudales)
-subscapular nerves (nn. subscapulares)
Long thoracic nerve
Passes caudally on the lateral surface of the thoracic part of the ventral serrate muscle, which it innervates!
Thoracodorsal nerve
Arises from the last cervical spinal nerve to innervate the broadest muscle of the back, latissimus dorsi.
Lateral thoracic nerve
Arises from the caudal parts of the plexus (C8 & Th1) to innervate the abdominal part of the cutaneous muscle and in extension, the skin caudal to the triceps and over the ventral thorax and abdomen.
Cranial and Caudal Pectoral nerves
Arise form the cranial part of the plexus and innervate the superficial pectoral msucle (and subclavian m. in ungulates), and the deep pectoral muscles.
Subscapular nerves
Arise as individual nerves or as a plexus from the cranial part of the brachial plexus to innervate the cranial and middle part of the sub scapular m.
What are three nerves with limited distribution, but of considerable functional importance?
- Suprascapular nerve (n. Suprascapularis)
- Musculocutaneoous nerve (n. Musculocutaneus)
- Axillary nerve (n. Axillaris)
The musculocutaneous nerve arises from the
Caudal to the suprascapular nerve from the brachial plexus
The musculotcutneous nerve runs
Parallel to the median nerve, which it joins in ungulates to form a loop around the axillary artery.
Axillary Nerve passes
Caudal to the shoulder joint to the lateral aspect of the limb
On the medial side, the Axillary nerve innervates the
Teres major muscle and the caudal third of the sub scapular muscle
The Axillary nerve also innervates the
Teres minor muscles
The axillary nerve branches to innervate the
Deltoid muscle and gives off a branch to the cleidobrachial muscle
The subscapular nerve passes between the
Subscapular and the supraspinous muscles to reach the cranial margin of the neck of the scapula, around which it winds to the lateral aspect of the bone.
The subscapular nerve innervates the
Supraspinous and Infraspinous muscles
3 nerves of the thoracic limb that extend from the brachial plexus all the way to the apex of the limb:
Radial nerve
Median nerve
Ulnar nerve
The radial nerve receives most of its fibers from the
8th cervical nerve
What is the largest nerve of the brachial plexus with the widest distribution?
Radial nerve
