Nerves Flashcards
Where does C1 CSN exit?
Lateral vertebral foramen of C1
What does C1 supply?
Muscles of atlanto occipital joint, part of sternohyoideus and sternothyrodieus
Where does C2 exit through?
Intervertebral foramen of C1 vertebrae
What does C2 supply to?
Cleidomastoideus and omotransversarius
What does C3 and C4 supply to ?
Epaxial and hypaxial muscles of neck, supplies brachipcephlicus parts, omotransversarius, and trapezius
What does C5 and C6 supply?
Diaphragm, becomes the phrenic nerve
What thoracic limb muscles are not supplied by the brachial plexus?
trapezius, omotransversarius, cleidomastoideus, cleidocervicalis
What are the CSN of the suprascapular nerve?
C6-C7
What does the suprascapular nerve innervate?
extensors of shoulder: supra and infraspinatus
What happens if the suprascapular nerve is damaged?
deviation of shoulder outward, muscles unable to function
What compensates for the suprascapular nerve?
Brachiocephalicus and biceps brachii
How do you diagnose a damaged suprascapular nerve?
Seeing abducted shoulder and prominent scapular spine
What re the CSN segments of the axillary nerve?
C6-C8
What does the axillary nerve innervate?
Flexors of shoulder: teres major and minor, deltoideus
What happens if the axillary nerve is damaged?
Flexors of shoulder paralyzed, no cutaneous sensation on lateral aspect of shoulder or craniolateral aspect of upper brachium
What compensates for the axillary nerve?
latissimus dorsi and triceps
What are the reflex tests that can be used for the axillary nerve?
Pinprick: to see if there is sensation in the autonomous zone
What are the CSN segments of the musculocutaneous nerve?
C6-C8
What does the musculocutaneous nerve innervate?
Flexors of the elbow: biceps brachii and brachialis
Sensory: medial cutaneous antebrachial nerve
What happens if the musculocutaneous nerve is damaged?
paralysis of elbow flexors, no cutaneous sensation on medial aspect of antebrachium
How do you know if the musculocutaneous nerve is damaged?
Animal fails to offer paw, reluctant to go upstairs
What reflex tests can be done on the musculocutaneous nerve?
Pin prick, biceps biceps reflex test
What are the CSN segments of the radial nerve?
C6-T1
What does the radial nerve innervate?
Extensors of elbow, carpus and digits
What are the branches that the radial nerve gives off?
Cranial cutaneous antebrachial nerve (small)
lateral cutaneous antebrachial nerve (thick)
Deep muscular branch
What are the digits supplied by the radial nerve?
digits 1 through axial aspect of digit 4
What happens if you injure the radial nerve at a high level?
Can’t bear weight, paralysis of extensors, no cutaneous sensation, knuckling over of paw
What happens if you injure the radial nerve at a lower level?
no cutaneous sensation, limb can still bear weight because triceps brachii is not affected, paw will knuckle over
What are the reflex tests for the radial nerve?
Triceps brachii, externsor carpi radialis reflex test
What are the CSN segments of the Median nerve?
C7-T1
What does the median nerve innervate?
Caudomedial group of muscles of antebrachium, flexors of the carpus and digits
What does the median nerve run with and where?
Through carpal canal with median artery, vein, and palmar branch of the ulnar nerve
What happens if the median nerve is injured?
Effect pronator teres and flexor carpi radialis
What is a reflex test for the median nerve?
Pin pick on the caudomedial side of the manus
What are the CSN segments of the Ulnar nerve?
C8-T1
What does the ulnar nerve innervate?
caudomedial group of muscles of the antebrachium, flexors of the carpus and digits
What is the branch that the ulnar nerve gives off?
Caudal cutaneous antebrachial nerve
What digits does the ulnar nerve innervate?
Dorsal and palmar aspects of carpus and digits 5 and abaxial portion of digit 4
What happens if the ulnar nerve is damaged?
flexor carpi ulnaris will be affected
What reflex tests can be used on the ulnar nerve?
pin prick tests, interossei reflex test
What are the the segments of the Cleidobrachial nerve?
C6-C7
What are the segments of the subscapular nerve?
C6-C7
What are the segments of the superficial pectoral nerve?
C6-C8
What are the segments of the thoracodorsal nerve?
C6-T1
What does the thoracodorsal nerve supply?
Latissimus dorsi
What are the segments of the deep pectoral nerve?
C6-T1
What are the segments of the long thoracic nerve?
C8-T1
What does the long thoracic nerve supply?
Serratus ventralis thoracis
What are the segments of the lateral thoracic nerve?
C8-T1
What does the lateral thoracic nerve supply?
Cutaneous trunci
How do lumbar nerves run as opposed to cervical nerves?
In a caudal direction as opposed to running dorsally and ventrally
What are the nerves that innervate the abdominal wall and pelvic limb?
Cranial iliohypogastric nerve (L1)
Caudal iliohypogastric nerve (L2)
ilioinguinal nerve (L3)
genitofemoral nerve (L4)
Which nerves do you have to be careful about during a spay
Cranial and caudal iliohypogastric nerves
What does the genitofemoral nerve pass through?
Inguinal canal
What branches form the femoral nerve?
L4-L6
What type of innervation does the femoral nerve have?
Motor and sensory: extensors of stifle (sartorius)
quadriceps femoris
What is a branch of the femoral nerve?
Saphenous nerve
What does the saphenous nerve innervate?
Skin on ventral half of medial aspect of thigh, medial stifle, leg and digits
What happens if the femoral nerve is injured?
Loss of sensory innervation, unable to extend stifle can’t bear weight
What are the segment of the obturator nerve?
L6
What is the innervation of the obturator nerve?
No sensory, adduction of the limb, supplies medial group muscles of the thigh ( gracilis, pectineous, obturator)
What happens if the obturator nerve is injured?
Limb may abduct from body when walking due to paralysis of adductors
What makes up the lumbosacral plexus?
L6-S2
What are the segments of the ischiatic/sciatic nerve?
L6-S1/2
What does the sciatic nerve innervate?
hamstring group of muscles: biceps femoris, semimembranosus, semitendinosus, tenissimus
outward rotators: gemeli, internal obturator, quadratus femoris
What are the two branches of the sciatic nerve?
Common peroneal/fibular nerve
What is the innervation of the Common peroneal/fibular nerve?
Motor and sensory to craniolater group of mOuscles of leg and dorsal aspect of pes
Superficial branch: supplies skin over craniolateral crus and pess
deep branch: supplies most of the muscle son dorsolateral aspect of leg: flexors of hock, extensor of digits
What happens if the common peroneal/fibular nerve is injured?
Unable to extend digits, knuckling over, overextension of the hock, can still bear weight
What does the tibial nerve innervate?
Motor and sensory to caudomedial group of leg muscles, extensors of tarsus, flexors fo the digits, plantar aspect
What are the two branches of the tibial nerve?
Lateral plantar nerve and Medial plantar nerve
What happens if the tibial nerve is injured?
Affects gastrocnemius, SDF, DDF,
total nerve injury: dropped hock, unable to bear weight as unable to extend hock
What are the tests for the tibial nerve?
Gastrocnemius tendon reflex, extensor thrust reflex
What does the cranial gluteal nerve innervate?
Middle and deep gluteal and tensor fascia lata
What does the caudal gluteal nerve innervate?
Superficial gluteal, piriformis
What is the purpose of the caudal gluteal nerve?
Aid in hip extension and abduction
What does the pudendal nerve supply?
Genitalia, pelvic diaphragm, sphincter ani externus, perineal region
What is the branch off of the pudendal nerve?
Caudal rectal nerve
What does the caudal rectal nerve supply?
external sphincter muscle
What happens if the pudendal nerve is damaged?
Urinary incontinence
What is cranial nerve I?
Olfactory nerve
What fibers are present in cranial nerve I?
SVA, sensory
Where does cranial nerve I pass through?
Holes in cribriform plate to reach olfactory bulb
What other nerve follow a similar route as cranial nerve I?
Terminal nerve and accessory olfactory nerve: flehmen response at the vomernasal organ
What is cranial nerve II?
Optic nerve
What fibers are associated with Cranial nerve II?
SSA, sensory
Where does the cranial nerve II arise from?
Retinal ganglion cells
What is cranial nerve III?
Oculomotor nerve
What fibers are associated with cranial nerve III?
Motor
What does cranial nerve III innervate?
Dorsal rectus muscle of the eye, medial and ventral rectus muscle of the eye
What does cranial nerve III do?
Control eye movement with CN IV and VI (trochlear and abducent)
What happens if the cranial nerve III is damaged?
Lateral strabismus
What is cranial nerve IV?
Trochlear nerve
What are the fibers associated with trochlear nerve
motor
What does this nerve innervate?
Dorsal oblique muscle of the eye
What happens if the trochlear nerve is damaged?
dorsolateral strabismus
What is cranial nerve V?
Trigeminal nerve
What nerve fibers are associated with trigeminal nerve
Both sensory and motor
What are the three branches of the trigeminal nerve?
Opthalmic, mandibular, maxillary
Where does the trigeminal nerve pass through?
Trigeminal canal in petrous part of temporal bone where trigeminal ganglion is located
What trigeminal nerve?does the mandibular branch of the trigeminal innervate?
Muscles of mastication: masseter, temporalis, medial and lateral pterygoidues, rostral belly of digastricus
What is the sensory innervation of the mandibular branch of the trigeminal nerve?
cheek, lower lip, tongue, lower teeth, external ear drum, external ear canal, skin of majority of head
