Lumbar Plexus Part 1

Question 1

The lumbar plexus is formed by the anterior primary rami of what cord levels?

Answer 1

L1-L3 and part of L4 with contribution from T12 via a communication with L1

Question 2

What muscles are supplied by the muscular branches from the anterior rami of the lumbar plexus?

Answer 2

quadratus lumborum, psoas major, and psoas minor (if present)

Question 3

What levels supply the quadratus lumborum?

Answer 3

L1-L4

Question 4

Which levels supply the psoas major?

Answer 4

L2-L4

Question 5

Which levels supply the psoas minor?

Answer 5

L1 and L2

Question 6

What levels contribute to the iliohypogastic nerve?

Answer 6

T12 and L1

Question 7

What are the main branches of the Lumbar plexus? (6)

Answer 7

Iliohypogastric, Ilioinguinal, Genitofermoral, Lateral Cutaneous of the thigh, Femoral, and Obturator (Irate Indian Girls…)

Question 8

Which branch of the lumbar plexus travels between the quadratus lumborum and the kidney then through the transverse abdominal muscle?

Answer 8

Iliohypogastric nerve

Question 9

After traveling through the transverse abdominal muscle and then between it and the internal abdominal oblique, what branch does the iliohypogastric nerve give off?

Answer 9

lateral cutaneous branch

Question 10

What does the lateral cutaneous branch supply?

Answer 10

the posterolateral gluteal region

Question 11

After giving off the lateral cutaneous branch what does the iliohypogastric nerve continue as and what does it supply?

Answer 11

anterior cutaneous branch which supplies the skin of the pubic region

Question 12

What two muscles does the iliohypogastric nerve supply?

Answer 12

internal abdominal oblique and transverse abdominal

Question 13

What levels contribute to the ilioinguinal nerve?

Answer 13

T12 and L1

Question 14

What strucuture does the ilioinguinal nerve travel through before meeting up with the spermatic cord/round ligament?

Answer 14

inguinal canal

Question 15

What area does the ilioinguinal nerve supply sensory innervation to in both sexes? in males? in females?

Answer 15

skin of upper medial thigh;
base of penis and anterior scrotum;
mons pubis and labium majus

Question 16

What muscles are supplied by the ilioinguinal nerve?

Answer 16

internal abdominal oblique and transverse abdominal

Question 17

What levels contribute to the genitofemoral nerve?

Answer 17

L1 and L2

Question 18

What muscle does the genitofemoral nerve pass through before dividing into the genital and femoral branches?

Answer 18

psoas major

Question 19

Which branch of the genitofemoral nerve passes throught the inguinal canal?

Answer 19

genital branch

Question 20

What does the genital branch of the genitofemoral nerve supply motor info to? sensory?

Answer 20

motor supply to the cremaster muscle;
sensory to skin of the superior anterior scrotum;
sensory to the mons pubis and labium majus

Question 21

What reflex is triggered by stimulating skin of the medial thigh resulting in the ipsilateral testical rising?

Answer 21

cremasteric reflex (tests the genital branch of the genitofemoral nerve)

Question 22

how does the femoral branch of the genitofemoral branch reach its destination? what does it supply?

Answer 22

passes into the thigh posterior to the inguinal ligament;

supplies skin of the upper anterior thigh

Question 23

What levels contribute to the lateral cutaneous nerve of the thigh?

Answer 23

L2 and L3

Question 24

T/F: the lateral cutaneous nerve supplies some motor innervation.

Answer 24

False;l it is purely sensitive.

Question 25

What does the lateral cutaneous nerve of the thigh supply sensory info to?

Answer 25

lateral thigh, superior to the knee

Question 26

Describe the path of the lateral cutaneous nerve of the thigh.

Answer 26

leaves the abdominal cavity by passing under the inguinal ligament, travels anterior to the sartorius and through the fascia lata to reach the skin

Question 27

What is the largest branch of the lumbar plexus? What levels contribute to this nerve?

Answer 27

femoral nerve;

L2, L3, and L4

Question 28

What muscle does the femoral nerve form behind and then emerge lateral to?

Answer 28

psoas major

Question 29

After passing behind the inguinal ligament, what structure does the femoral nerve enter just lateral to the femoral artery?

Answer 29

femoral triangle

Question 30

After leaving the femoral triangle, the femoral nerve travels inferiorly and medially into what structure before reaching the medial aspect of the leg?

Answer 30

adductor canal

Question 31

T/F: the femoral nerve only gives off branches in the abdomen and the femoral triangle.

Answer 31

True

Question 32

What does the femoral nerve supply with its branches in the abdomen?

Answer 32

muscular branches to iliacus and pectineus;

also sends some fibers to the femoral artery

Question 33

What does the femoral nerve divide into once beyond the inguinal ligament?

Answer 33

anterior and posterior divisions

Question 34

What 3 nerves does the anterior division of the femoral nerve give rise to?

Answer 34

intermediate cutaneous nerve of the thigh,
medial cutaneous nerve of the thigh,
nerve to the sartorius