Unit 5 lumbosacral plexus

Question 1

What makes up the lumbar plexus?

Answer 1

VPR from L1-L4
Also, in 50% of people there is also a contribution of T12 VPR

Question 2

Where is lumbar plexus?

Answer 2

under psoas major muscle

Question 3

Divisions of lumbar plexus

Answer 3

Both anterior and posterior divisions. Most nerves branch from these divisions.

Some nerves, however, branch directly from the VPR

Question 4

Nerves from lumbar plexus that come directly off the VPR?

Answer 4

subcostal nerve
iliohypogastric nerve
ilioinguinal nerve
genitofemoral nerve

Question 5

subcostal nerves comes from?

Answer 5

T12 VPR

Question 6

Iliohypogastric nerve comes from?

Answer 6

L1 VPR

Question 7

ilioinguinal nerve comes from?

Answer 7

L1VPR

Question 8

Genitofemoral nerve comes from?

Answer 8

L1- L2 VPR

Question 9

nerves from posterior division of lumbar plexus?

Answer 9

lateral femoral cutaneous nerve
femoral nerve

Question 10

lateral femoral cutanesous nerves comes from?

Answer 10

L2-L3

Question 11

femoral nerve comes from?

Answer 11

L2-L4

Question 12

nerves from Ant. division of lumbar plexus?

Answer 12

obturator nerve
accessory obturator nerve

Question 13

where does obturator nerve originate?

Answer 13

L2-L4

Question 14

where does accessory obturator nerve originate?

Answer 14

L3-L4

Question 15

how often is accessory obturator nerve present?

Answer 15

9%

Question 16

what does acessory obturator nerve supply when present?

Answer 16

pectineous muscle

Question 17

What forms sacral pleuxs?

Answer 17

ventral primary rami of L4-S4

Question 18

how does sacral plexus divide?

Answer 18

all VPR form anterior and posterior divisions

Question 19

What makes up the lumbosacral trunk?

Answer 19

L4 L5 and S1 VPR

Question 20

distal continuation of lumbosacral trunk?

Answer 20

sciatic nerve

Question 21

What forms sacral plexus?

Answer 21

S1-S4 VPR

Question 22

nerves from ant. division of sacral plexus?

Answer 22

tibial nerve
post. femoral cutaneous nerve
Pudendal
pelvic splanchnic nerve
n. to levator ani

Question 23

where does tibial nerve originate?

Answer 23

ant division of L4-L5 and S1-S3

Question 24

where does post femoral cutaneous nerve originate?

Answer 24

ant. division of S2-S3
post. divisions of S1-S2

Question 25

where does pudendal nerve originate?

Answer 25

ant. divisions of S2-S4

Question 26

where does pelvic splanchnic nerve originate?

Answer 26

ant. divisions of S2-S4

Question 27

where does levator ani originate?

Answer 27

ant. divisions of S3-S4

Question 28

function of tibial nerve?

Answer 28

motor to post let and hamstring sesory/motor to plantar surface of foot

Question 29

function post. femoral cutaneous nerve>

Answer 29

sensory to post thigh

Question 30

function of pudendal nerve?

Answer 30

sensory to the external genitalia, motor to urethral and anal sphincters

Question 31

fucntion of pelvic splanchnic nerve?

Answer 31

parasymphathetic to pelvic viscera

Question 32

function of levator ani?

Answer 32

make up the pelvic diaphragm

Question 33

nerves from post. division of sacral plexus?

Answer 33

common peroneal nerve post femoral cutaneous nerve

Question 34

what nerve comes from both ant. and post. divisions of sacral plexus?

Answer 34

post femoral cutaneous nerve

Question 35

where does common peroneal nerve originate?

Answer 35

post divisions of L4-L5 S1-S2 VPR

Question 36

function of common peroneal nerve?

Answer 36

motor to ant leg and dorsal surgace of the foot, hamstring muscle sensory to dorsal surface of the foot