Lumbosacral Plexus

Question 1

Which anterior rami make up the lumbosacral plexus?

Answer 1

L1 - L5; S1 - S4

Question 2

Which spinal nerves make up the lumbar plexus?

Answer 2

Anterior rami of spinal nerves L1 - L4

Question 3

Which muscles does the lumbar plexus innervate?

Answer 3

Muscles of anterior and medial thigh

Question 4

What contributes to the sacral plexus?

Answer 4

Anterior rami of spinal nerves L4 - L5 and S1 - S4

Question 5

Which muscles does the sacral plexus innervate?

Answer 5

Muscles of the gluteal region

Question 6

Which plexus does the sciatic nerve originate from?

Answer 6

Sacral plexus

Question 7

Which regions does the sciatic nerve innervate?

Answer 7

Posterior thigh, leg, foot

Question 8

Which nerves exit through the greater sciatic foramen? Which regions do they innervate?

Answer 8

Gluteal nerves - Gluteal region

Sciatic nerve - Posterior thigh, leg, foot

Question 9

Which nerve exits deep to the inguinal ligament? What region does it innervate?

Answer 9

Femoral nerve - Anterior thigh

Question 10

Which nerve exits through the obturator foramen? Which region does it innervate?

Answer 10

Obturator nerve - Medial thigh

Question 11

Which nerves arise from the lumbar plexus?

Answer 11

Iliohypogastric nerve
Ilioinguinal nerve
Genitofemoral nerve
Lateral cutaneous nerve of thigh
Femoral nerve
Obturator nerve

Question 12

Which anterior ramus contributes to the iliohypogastric nerve?

Answer 12

L1

Question 13

Which anterior ramus contributes to the ilioinguinal nerve?

Answer 13

L1

Question 14

Which anterior rami contribute to the genitofemoral nerve?

Answer 14

L1 - L2

Question 15

Which anterior rami contribute to the lateral cutaneous nerve of the thigh?

Answer 15

L2 - L3

Question 16

Which anterior rami contribute to the femoral nerve?

Answer 16

L2 - L4

Question 17

Which anterior rami contribute to the obturator nerve?

Answer 17

L2 - L4

Question 18

What is the lumbosacral trunk? Where does it travel?

Answer 18

Anterior rami of L4 - L5 that forms sacral plexus with S1 - S4 anterior rami

Descends into pelvis

Question 19

What does the iliohypogastric nerve innervate?

Answer 19

Abdominal muscles
Skin overlying iliac crest
Hypogastric region

Question 20

Which muscle is a landmark for finding both the iliohypogastric and ilioinguinal nerves?

Answer 20

Quadratus lumborum

Question 21

Which regions does the ilioinguinal nerve innervate?

Answer 21

Abdominal muscles
Skin of genital region
Skin of medial thigh region

Question 22

Where does the ilioinguinal nerve typically lie in relation to the iliohypogastric nerve?

Answer 22

Inferiorly

Question 23

Where do the iliohypogastric and ilioinguinal nerves exit?

Answer 23

They disappear into the muscles of the anterolateral abdominal wall

Question 24

Where is the genitofemoral nerve found?

Answer 24

It appears on anterior aspect of psoas major

Question 25

What does the femoral branch of the genitofemoral nerve innervate?

Answer 25

Skin on anterior surface of thigh

Question 26

What does the genital branch of the genitofemoral nerve innervate?

Answer 26

Cremaster muscle

Skin of genitals

Question 27

Where does the genital branch of the genitofemoral nerve lie in relation to the femoral branch?

Answer 27

Medially

Question 28

What does the lateral cutaneous nerve of thigh innervate?

Answer 28

Skin on anterolateral surface of thigh

Question 29

Over which muscle does the lateral cutaneous nerve of thigh travel?

Answer 29

Iliacus

Question 30

Where does the lateral cutaneous nerve of thigh exit the pelvis?

Answer 30

Medial to the ASIS, deep to the inguinal ligament

Question 31

What does the femoral nerve innervate?

Answer 31

Iliacus

Anterior thigh

Question 32

Where is the femoral nerve found?

Answer 32

Lateral to psoas major

Question 33

What does the obturator nerve innervate?

Answer 33

Medial thigh

Question 34

Where does the femoral nerve exit the pelvis?

Answer 34

Deep to inguinal ligament

Question 35

Where does the obturator nerve exit the pelvis?

Answer 35

Obturator foramen

Question 36

Where is the obturator nerve found?

Answer 36

Medial to psoas major