Lumbar plexus

Question 1

ventral rami

Answer 1

• formed by the ventral rami of L1-4

Question 2

location

Answer 2

• located between the anterior and posterior bellies of psoas major
• Merges with the sacral plexus through the lumbosacral trunk (arises from L4&L5).!

Question 3

general muscle supply

Answer 3

• Consists of a group of 6 nerves (including lateral femoral cutaneous nerve) that supply the
  o lower abdomen
  o extensor muscles of the thigh
  o adductor muscles of the thigh

Question 4

ILIOHYPOGASTRIC nerve

Answer 4

ABDOMEN
Lower parts of I Obl abdominis & TAbd
come from L1

Question 5

ILIOINGUINAL nerve

Answer 5

ABDOMEN
Lower parts of I Obl abdominis & TAbd
comes from L1
follows along iliac crest

Question 6

femoral nerve

Answer 6

ANTERIOR HIP & ANTERIOR COMPARTMENT OF THIGH - heads towards inguinal canal
1.	iliacus
2.	Sartorius
3.	Rectus femoris
4.	 Vastus lateralis
5.	 vastus intermedius
6.	 vastus medialis
(Pectineus)

Question 7

obturator

Answer 7

MEDIAL COMPARTMENT OF THIGH - goes through obturator foramen
1.	Gracilis
2.	Pectineus
3.	Adductor longus
obturator nerve between 4 and 5
4.	 Adductor brevis
5.	 adductor magnus
Obturator externus

Question 8

GENITOFEMORAL

Answer 8

INGUINAL CANAL
Cremaster muscle
L1,2
pierces out of psoas major

Question 9

lateral femoral cutaneous nerve

Answer 9

sensory to anterolateral thigh

Question 10

Anatomical landmarks of the nerve

- ILIOHYPOGASTRIC nerve

Answer 10

L1
Crosses anterior surface of quadratus lumborum, posterior to kidney. Pierces transversus abdominis. Cutaneous branches supply posterolateral gluteal & pubic region skin.
kidney infection may cause irritation of the nerves and hence pain sensation on the skin of the inguinal region

Question 11

Anatomical landmarks of the nerve

- ILIOINGUINAL nerve

Answer 11

L1
Crosses Quadratus lumborum just below iliohypogastric, pierces transversus abdominis & Internal Oblique near anterior iliac crest and enters inguinal canal.

Question 12

Anatomical landmarks of the nerve

- GENITOFEMORAL

Answer 12

L1 and 2
Pierces through psoas major then emerges on its anterior surface & descends posterior to ureter.
Has genital and femoral branches
Genital branch enters the inguinal canal and supplies
- Motor innervations: cremaster muscle;
- Sensory innervations: scrotum, labia majora
Femoral branch enters anterior thigh and supplies skin over femoral triangle

Question 13

Anatomical landmarks of the nerve

- lateral femoral cutaneous nerve

Answer 13

L2&3
Emerges from lateral border of psoas, crosses iliacus toward ASIS, passes posterior to the inguinal ligament to enter the thigh
Tight closing (jeans), pregnancy, adiposity can compress the nerve causing numb, tingling or burning sensation.

Question 14

Anatomical landmarks of the nerve

FEMORAL

Answer 14

L2-4
Enters the thigh deep to the inguinal ligament
Visible in the femoral triangle
Supplies muscles of the: anterior compartment of the thigh
Terminates as cutaneous branches to medial & anterior thigh & the saphenous nerve (sensory supply of medial thigh, leg, and foot).

Question 15

Anatomical landmarks of the nerve

OBTURATOR

Answer 15

L2-4
Emerges from medial side of psoas major near pelvic brim, posterior to iliac vessels & passes through the obturator foramen
Supplies muscles and skin of the medial thigh