Lumbosacral Plexus

Question 1

Cervical intumescence

Answer 1

C6-T2
Thoracic limbs innervation

Question 2

Lumbar intumescence

Answer 2

L4-S3
Pelvic limbs and pelvic viscera innervation

Question 3

Functional regions of the spinal cord

Answer 3

Cervical C1-5 (neck)
Cervical intumescence C6-T2 (thoracic limbs)
Thoracolumbar T3-L3 (truck)
Lumbosacral intumescence L4-S3 (pelvic limbs and pelvic viscera)
Caudal segments Cd1-5 (tail)

Question 4

Lumbosacral plexus

Answer 4

Ventral branches of lumbar and sacral spinal nerves

Question 5

Nerves that innervate abdominal wall cranial to caudal

Answer 5

Cranial

Costoabdominal nerve
Cranial iliohypogastric nerve
Caudal iliohypogastric nerve
Ilioinguinal nerve
Lateral cutaneous femoral nerve

Caudal

Question 6

Genitofemoral nerve innervates

Answer 6

Formed by ventral branches of L3 and L4 spinal nerves

Motor to cremaster muscle

Sensory from skin in inguinal region proximal medial thigh

Question 7

Obturator nerve innervates

Answer 7

Arises from L4 L5 L6 spinal nerves

Innervates external obturator muscle pectineus muscle, gracilis muscle, adductor muscle

Question 8

Femoral nerve innervates

Answer 8

Arises from L4, L5 L6 spinal nerves

Emerges from iliopsoas muscle

Innervates iliopsoas muscle, quadriceps femoris muscle and sartorius muscle

Gives rise to Saphenous nerve

Sensory innervation to cutaneous skin of medial femoral, genual, tibial, and pes regions

Question 9

Caudal cutaneous femoral nerve

Answer 9

Follows caudal gluteal artery to level of ischiatic tuberosity

Terminates in skin on proximal caudal half of thigh

Question 10

Nerves of Lumbosacral trunk

Answer 10

Caudal gluteal nerve
Cranial gluteal nerve
Sciatic nerve

Question 11

Lumbosacral trunk

Answer 11

Formed by ventral branches of L6 L7 S1 and S2

Near greater ischiatic notch

Question 12

Caudal gluteal nerve

Answer 12

Superficial gluteal muscle

Question 13

Cranial gluteal nerve

Answer 13

Middle gluteal muscle
Piriformis muscle
Deep gluteal muscle
Tensor fasciae latae muscle

Question 14

Sciatic nerve

Answer 14

Arises from L6 L7 S1 S2 spinal nerves

Courses over greater ischiatic notch dorsal and caudal to coxal joint

Question 15

Sciatic nerve innervates

Answer 15

Internal obturator muscle
Gemelli muscle
Quadratus femoris muscle
Biceps femoris muscle
Semimembranosus muscle
Semitendinosus muscle

Question 16

Sciatic nerve gives rise to

Answer 16

Lateral and caudal cutaneous sural nerves (arise from perineal and tibial components of sciatic nerve)

Innervation to lateral and caudal surfaces of crus

Question 17

Sciatic nerve divides into

Answer 17

Common perineal (fibular) nerve
Tibial nerve

Question 18

Common perineal (fibular) nerve

Answer 18

Innervates flexors of the tarsal joint and extensors of the digit

Question 19

Tibial nerve

Answer 19

Innervates extensors of tarsal joint and flexors of the digits

Question 20

Branches of common peroneal (fibular) nerve

Answer 20

Deep peroneal nerve
Superficial peroneal nerve

Question 21

Deep peroneal nerve

Answer 21

Innervates cranial tibial muscle long digital extensor muscle and peroneus longus muscle

Courses distally with cranial tibial artery

Question 22

Superficial peroneal nerve

Answer 22

Innervates lateral digital extensor nerve and peroneus brevis muscle

Question 23

Tibial nerve innervates

Answer 23

Arises from L7 S1 spinal nerves

Innervates gastrocnemius muscle superficial digital flexor muscle deep digital flexor muscle and popliteus muscle