Hindlimb Innervation Flashcards
What is the most common clinical signs associated with compromised motor innervations?
Weakness in lower legs, muscle atrophy and gait defects
What are the hip extensors
Gluteal muscles: super. gluteal, deep gluteal, middle gluteal
Hamstrings: biceps femoris, semimembranosus, semitendinosus
What are the hip flexors?
TFL, Sartorius, iliopsoas
What are the muscle adductors if the hindlimb
Adductor, pectineus, gracilis
What are the stifle extensors?
Quadriceps:
Recuts femoris
Vastus medialis
V. Intermedius
V. Lateralis
What are the stifle joint flexors?
Popliteus
Lumbosacral plexus
From L4-S2
Gives origin to the nerves that innervate the hindlimb
What does L3 give rise to?
Illioinguinal and genitofemoral (L3&L4) nerves
What does the femoral branch of the Genitofemoral nerve innervate?
Cutaneous innervation to the proximal medial thigh
What does the genital branch of the Genitofemoral nerve innervate?
Spermatic fascia
Cremaster m.
Scrotum
Lateral cutaneous femoral nerve
Originates from L4
Provides sensory innervation to the cranio-lateral surface of the thigh
Femoral nerve
L4-L6
Motor innervation to the stifle extensors (quadriceps)
What is the sensory innervation of the femoral nerve?
Saphenous branch
To the medial surface of the thigh, stifle and hock
Clinical significance of the femoral nerve
Paralysis of the quadriceps
Loss of weight bearing
Loss of sensation in the medial surface of the limb
Obturator nerve
L4-L6
Supplies the adductor muscles of the thigh
Clinical significance of the obturator nerve
Looses ability to adduct the limbs, so the limbs remain abducted ( dystocia and calving)
Lumbosacral trunk
L7-S1&2
Cranial gluteal
Cd. Gluteal
Cd. Cutaneous femoral
What does the cranial gluteal supply?
Middle and deep gluteal
Tensor fasciae lata
What does the cranial gluteal supply?
Super. Gluteal m. (Hip extensor)
What does the cd. cutaneous femoral supply?
Sensory to cd. thigh
Sciatic nerve
Distal communication of the lumbosacral trunk
Supplies the internal obturator, gemelli, quadriceps femoris, hamstrings group
What are the branches of the sciatic nerve?
Common peroneal and tibial
Sensory innervation to the lateral surface of the limb distal to the stifle
Motor innervation to the leg muscles
What branches are of the common peroneal
Superficial branch: skin; dorsal surface of the leg and foot
Deep branch: hock flexors/ digit extensors
Tibial nerve
Passes between the 2 heads of gastrocnemius
What is the cutaneous branch of the common peroneal?
Lateral sural nerve: skin/ lateral surface of leg
What is the cutaneous branch of the sciatic nerve?
Caudal sural nerve
What do the muscular branches of the sciatic nerve innervate?
Muscular branches of the gastrocnemius and caudal crual muscles
Medial & lateral plantar of the sciatic nerve
Supplies sensory nerves to planter surface of foot
What are the clinical considerations of the sciatic nerve?
Largest nerve in the body
What can the sciatic nerve be damaged from?
Fracture of pelvis or femur
Dislocation of hip
Injections
Trauma
What can damages of the common peroneal cause?
Over extension of hock
Overflexion of digits
Atrophy to innervate muscles
Dog will flick the paw forward to bare weight
Lost sensation on dorsal aspect of hock and foot
What can damages to the tibial nerve cause?
Overflexion of hock
Overextension of digits
Atrophy to innervated muscles
Limb is lowered when applying weight
Lost sensation on plantar aspect of hock and foot
Pudendal nerve
S2-S3
Lies lateral to levator and coccygeus
Main trunk supply sensory innervation to prep use, scrotum, udder
How does the pudendal nerve end?
As dorsal nerve of penis clitoris
Superficial branch of the pudendal nerve
Supplies skin of anus, vulva, and ventral perineal region
What do the deep branches of the pudendal nerve supply?
Motor nerves to perineal muscles that include reproductive organs muscle
Caudal rectal nerves
Origin: most caudal sacral nerves
Provides sensory innervation to rectum, anus, perineal skin
What are the motor fibers to of the caudal rectal nerves?
Dorsal perineal muscles
External anal sphincter
Levanter ani
Clinical consideration of the caudal rectal nerves
When fixing an external anal sphincter the vet could hit the nerve.