Cat Spinal Nerves
1. Branchial Plexus- cervical nerves 6-8 along with the first thoracic nerve are referred to as the brachial plexus.
a. Vagus nerve (X)- extends posteriorly from the nodose ganglion and running along the common carotid artery in a sheath closely applied to the trachea.
b. Superior cervical and nodose ganglia- a pair of swellings, which occur just ventral to the hpoglossal nerve.
c. 6th cervical nerve and branching- extends to the area of the shoulder joint, thwer ehte suprascpular nerve originates.
d. Suprascapular nerve-passes between the supraspinatus and subscapularis muslces, supplying the supraspinatus and infraspinatus muscles.
e. 1st subscapulalar nerve and branching- form the 6th and 6th cervical nerves, which innervates the subscapularis muscle and travels with the subscapular vessels.
f. Axillary nerve- originates from the 6th and 7th cervical nerves and travels with the posterior humeral circumflex vessels benearth the posterior edge of the biceps branchii muscle to innervate lateral shoulder muslces such as the teres major, teres minor, deltoids, and the cleidobrachialis muscles.
g. Radial nerve- originates from vercial nerves 6,7,8 and the first thoracic nerve. Travels with the deep brancial vessels and innervates the triceps brachii, epitroclearis and extensor muslces of the forelimb.
h. Median nerve- arises from the cervical nerves, 7, 8 and the first thoracic nerve, and travels with the branchial artery and passes through the supracondyloid foramen to innervate some of the flexor muscles of the forelimb.
i. Ulnar nerve-arises from the 8th vervical and first thoracic nerves, travels paralle with the median nerve, crosses the medial epicondyle of the humerus, and innervates flexor muscles of the forelimb.
j. Intercostal nerves- supply intercostal muscles, lateral thoracic muscles and some abdominal muscles, back muscles and skin.
2. Lumbosacral Plexus (ventral)
a. Lateral femoral nerve- originates primarily from the fifth lumbar nerve, with minor contributions from the 4th lumbar nerve. It emerges form beneath the psoas minor muscle, passes over the illiopsoas muslce and travels with the illiolumbar vessles and supplies the lateral surfaces of the hip and thigh regions.
b. Femoral nerve- passes between the illiopsoas and psoas minor muscles, penetrating the abdominal wall and subdivides into three branches.
c. Obturator nerve-originates from the 6th nerve, with contributions form the fifth and seventh lumbar nerves. It passes into the pelvic region through the obturator foramen, where it branches to supply the thigh adductors, pectineus, gracilis and obturator externus muscles.
d. Saphenous nerve- one of the branches of the femoral nerve, runes parallels to the femoral and saphenous vessels.
e. Lumbosacral trunk- or cord, appears medial to the obturator nerve and is formed by fibers of the 6th and 7th lumbar nerves. As the cord passes caudally it recieves fibers from the sacral nerves.
3. Lumnosacral Plexus (dorsal)
a. Ischiadic (=sciatic) nerve- larges nerve, which extends form the lumbosacral cord. It courses over the lateral muscles of the thight giving off the muscular branch.
b. Tibial nerve-extends between the heads of the gastrocnemius muscle and innervates the fastrocnemius, plantaris, soleus and other muslces associated with extensino and flexion of the foot.
c. Common peroneal nerve- pieces the lateral head of the gastrocnemius muscle to supply the peroneal muscles, the tibialis anterior and extensor digitorum longus muscles, eventually innervating muscles of the digis.
d. Muscular branch