Vessels & Nerves Of The Thoracic Limb

Question 1

The brachial plexus is usually formed by the ventral branches of the..

Answer 1

6th, 7th, & 8th cervical spinal nerves and the 1st & 2nd thoracic spinal nerves

Question 2

The brachial plexus gives origin to the nerves that innervate the muscles and skin of the…

Answer 2

Thoracic limb, parts of the shoulder girdle musculature and the lateral wall of the thorax and abdomen.

Question 3

What are some exception in regards to the brachial plexus origin?

Answer 3

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

Question 4

Brachial plexus branches are usually mixed:

Answer 4

The cerebrospinal fibers are joined by autonomous fibers from the stellate ganglion.

Question 5

The brachial plexus is located:

Answer 5

Cranial to the first rib between the long muscle of the neck and the scaleni muscles

Question 6

Where do the roots of the brachial plexus reach?

Answer 6

The medial aspect of the shoulder

Question 7

The branches of the brachial plexus include:

Answer 7

-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)

Question 8

Long thoracic nerve

Answer 8

Passes caudally on the lateral surface of the thoracic part of the ventral serrate muscle, which it innervates!

Question 9

Thoracodorsal nerve

Answer 9

Arises from the last cervical spinal nerve to innervate the broadest muscle of the back, latissimus dorsi.

Question 10

Lateral thoracic nerve

Answer 10

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.

Question 11

Cranial and Caudal Pectoral nerves

Answer 11

Arise form the cranial part of the plexus and innervate the superficial pectoral msucle (and subclavian m. in ungulates), and the deep pectoral muscles.

Question 12

Subscapular nerves

Answer 12

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.

Question 13

What are three nerves with limited distribution, but of considerable functional importance?

Answer 13

1. Suprascapular nerve (n. Suprascapularis)
2. Musculocutaneoous nerve (n. Musculocutaneus)
3. Axillary nerve (n. Axillaris)

Question 14

The musculocutaneous nerve arises from the

Answer 14

Caudal to the suprascapular nerve from the brachial plexus

Question 15

The musculotcutneous nerve runs

Answer 15

Parallel to the median nerve, which it joins in ungulates to form a loop around the axillary artery.

Question 16

Axillary Nerve passes

Answer 16

Caudal to the shoulder joint to the lateral aspect of the limb

Question 17

On the medial side, the Axillary nerve innervates the

Answer 17

Teres major muscle and the caudal third of the sub scapular muscle

Question 18

The Axillary nerve also innervates the

Answer 18

Teres minor muscles

Question 19

The axillary nerve branches to innervate the

Answer 19

Deltoid muscle and gives off a branch to the cleidobrachial muscle

Question 20

The subscapular nerve passes between the

Answer 20

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.

Question 21

The subscapular nerve innervates the

Answer 21

Supraspinous and Infraspinous muscles

Question 22

3 nerves of the thoracic limb that extend from the brachial plexus all the way to the apex of the limb:

Answer 22

Radial nerve
Median nerve
Ulnar nerve

Question 23

The radial nerve receives most of its fibers from the

Answer 23

8th cervical nerve

Question 24

What is the largest nerve of the brachial plexus with the widest distribution?

Answer 24

Radial nerve

Question 25

The radial nerve innervates all

Answer 25

Extensor muscles of the thoracic limb, expect those of the shoulder joint