Lumbar plexus

Question 1

describe the lumbar plexus

Answer 1

• originates from ventral rami of L1-4.
• formed withing the psoas major muscle and its main branches emerge either lateral to, on the surface of, or medial to the psoas major muscle.

Question 2

what is the root of the iliohypogastric nerve?

Answer 2

T12, L1

Question 3

what is the root of the ilioinguinal nerve?

Answer 3

L1

Question 4

what is the root of the genitofemoral nerve?

Answer 4

L1, L2

Question 5

what is the root of the lateral cutaneous nerve?

Answer 5

L2, L3

Question 6

what is the root of the obturator nerve?

Answer 6

L2, L3, L4

Question 7

what are the roots of the femoral nerve?

Answer 7

L2, L3,L4

Question 8

what does the iliohypogastric nerve innervate?

Answer 8

internal oblique and transversus abdominis

Question 9

what does the ilioinguinal nerve innervate?

Answer 9

Motor Functions: Innervates the internal oblique and transversus abdominis.

Sensory Functions: Innervates the skin on the superior antero-medial thigh.

Question 10

what does the genitofemoral nerve innervate?

Answer 10

Motor Functions: The genital branch innervates the cremasteric muscle.

Sensory Functions: The genital branch innervates the skin of the anterior scrotum (in males) or the skin over mons pubis and labia majora (in females).
The femoral branch innervates the skin on the upper anterior thigh.

Question 11

what does the lateral femoral
cutaneous nerve innervate?

Answer 11

sensory innervation of outer part of thigh

Question 12

what does the obturator nerve innervate?

Answer 12

Motor Functions: Innervates the muscles of the medial thigh – the obturator externus, adductor longus, adductor brevis, adductor magnus and gracilis.

Sensory Functions: Innervates the skin over the medial thigh.

Question 13

what does the femoral nerve innervate?

Answer 13

the muscles of anterior thigh - iliacus, pctineus, sartorius and quadriceps femoris.

Question 14

referred pain from foregut structures may be felt in which region?

Answer 14

epigastric

Question 15

referred pain from midgut structures is felt in what region?

Answer 15

umbilical

Question 16

referred pain from hindgut structures is felt in which region?

Answer 16

suprapubic

Question 17

which nerve pierces the psoas major muscle?

Answer 17

genitofemoral

Question 18

what is the relation of the iliohypogastric nerve to the psoas major muscle?

Answer 18

superolateral

Question 19

what is the relation of the ilioinguinal nerve to the psoas major muscle?

Answer 19

lateral, inferior and often parallel to iliohypogastric nerve

Question 20

what is the relation of the lateral femoral cutaneous nerve to the psoas major muscle?

Answer 20

lateral

Question 21

what is the relation of the obturator nerve to the psoas major muscle?

Answer 21

inferomedial border

Question 22

what is the relation of the femoral nerve to the psoas major muscle?

Answer 22

inferolateral border

Question 23

label this lumbar plexus

Answer 23