Lumbosacral Plexus

Question 1

site of division into left and right common iliac arteris

Answer 1

L4

Question 2

external iliac becomes femoral artery when,..

Answer 2

passes under inguinal ligament

Question 3

branches of internal iliac artery

Answer 3

anterior and posterior division

Question 4

anterior division of internal iliac fn

Answer 4

supply pelvic viscera, perineum structures, gluteal region

Question 5

posterior division of internal iliac fn

Answer 5

supply gluteal muscles, lower back. nearby sacral nerves and meninges

Question 6

3 main branches of posterior division of internal iliac artery and fn

Answer 6

superior to inferior

iliolumbar- psoas

lateral sacral- meninges/ sacral spinal roots

superior gluteal- gluteal muscles

Question 7

3 MSK related branches of anterior divison of internal iliac

Answer 7

superior to inferior

obturator- medial thigh

inferior gluteal- gluteal muscles

internal pudenal- perineum

Question 8

lumbosacral plexus is collection of…

Answer 8

ventral rami of lumbar and sacral spinal nerves- often separated into lumbar and sacral

Question 9

lumbar plexus spinal nerves

Answer 9

L1-L4 ventral rami

Question 10

3 main sensory nerves of lumbar plexus and primary branches

Answer 10

ilioinguinal- L1 that course thru inguinal canal, sensation in scrotum/ labia

lateral femoral cutaneous nerve- L1,2, goes beneath inguinal ligament and sensation to anterolateral thigh

genitofemoral- L1,2 and has genital branch and femoral branch

Question 11

2 main motor lumbar plexus nerves

Answer 11

femoral- L2,3,4 beneath inguinal ligament and innervates anterior thigh muscles

obturator- also L2,3,4 passes thru obturator canal, innervates medial thigh muscles

Question 12

sacral plexus nerve roots

Answer 12

L4,5 and S1-4

Question 13

list lumbosacral plexus nerves

Answer 13

lumbosacral trunk
sciatic nerve
superior gluteal
inferior gluteal
posterior femoral cutaneous
pudenal
obturator internus and quadratus femoris nerves

Question 14

lumbosacral trunk

Answer 14

portion of L4,5 ventral rami unite, join w/ large sacral nerves

Question 15

sciatic nerve

Answer 15

large nerve formed by L4,5 and S1,2,3

exits greater sciatic foramen and innervates muscles througout lower limb

Question 16

superior gluteal nerve

Answer 16

L4,5 and S1 exits greater sciatic forament and innervates hip abductors

Question 17

inferior gluteal nerve

Answer 17

L5, S1,2 exits greater sciatic foramen and innervates gluteus maximus

Question 18

posterior femoral cutaneous nerve

Answer 18

S1,2,3 sensory to posterior thigh

Question 19

pudendal nerve

Answer 19

S2,3,4 exits greater sciatic foramen and enters lesser sciatic foramen- sensory to external genitalia