Lumbosacral Plexus

Question 1

Off of T12. About 50% of people have a contribution from T12.
-No divisions, derived from VPR itself
-Innervates area underneath the Diaphragm and also some of the larger abdominal muscles

Answer 1

Subcostal Nerve

Question 2

Derived from L1 VPR.
-No divisions, derived from VPR itself
-Superior Division of L1
-Supplies motor to several big muscles like the External Abdominal Oblique m.
-Sensory also to the lateral side of hips, area between umbilicus and pubic bone

Answer 2

Iliohypogastric Nerve

Question 3

Derived from L1 VPR
-No divisions, derived from VPR itself
-Inferior Division

Answer 3

Ilioinguinal Nerve

Question 4

Nerve that supplies the lateral thigh with sensation
-Derived from the Posterior Divisions of L2-L3

Answer 4

Lateral Femoral Cutaneous Nerve

Question 5

Nerve that supplies sensation to the genitalia (males and females) and motor (males only).
-No divisions, derived from VPR itself (L1-L2)

Answer 5

Genitofemoral Nerve

Question 6

-Derived from the Posterior Divisions of L2-L4

Answer 6

Femoral Nerve

Question 7

-Present in about 9% of the population
-Derived from the Anterior Divisions of L3-L4
-Innervates the Pectineus Muscle

Answer 7

Accessory Obturator Nerve

Question 8

-Derived from the Anterior Divisions of L2-L4
-Supplies the Pectineus Muscle (if no accessory present)

Answer 8

Obturator Nerve

Question 9

A nerve mesh passing underneath the Psoas Major Muscle

Answer 9

Lumbar Plexus

Question 10

Which nerves in the Lumbar Plexus come directly from the VPR itself? (no divisions)

Answer 10

-Subcostal nerve (T12)
-Iliohypogastric (L1)
-Ilioinguinal (L1)
-Genitofemoral (L1-L2)

Question 11

VPR of L4-S4.
-All VPR form Anterior and Posterior Divisions
-All nerves are derived from Anterior or Posterior Divisions (none come off of VPR itself)

Answer 11

Sacral Plexus

Question 12

Formed by the VPR of L4, L5, and S1
-Ties in Lumbar Plexus with the Sacral Plexus
-Later on, becomes the Sciatic Nerve (With contributions from S2-S5 VPR)

Answer 12

Lumbosacral Trunk

Question 13

Nerve derived from the Anterior Divisions of L4-L5, S1-S3.
-Supplies motor to the posterior leg, and sensory & motor to the plantar surface of the foot, and motor to the hamstring muscles

Answer 13

Tibial Nerve (L4-L5, S1-S3)

Question 14

-Nerve derived from the Anterior Divisions of S2-S3
-Supplies sensation to the Posterior Thigh

Answer 14

Posterior Femoral Cutaneous Nerve (S2-S3)

Question 15

Nerve derived from the Anterior Divisions of S2-S4
-Supplies sensory to the external genitalia of both sexes and motor to the urethral and anal sphincters.
-Controls emptying mechanisms via sensors on urinary and bowel systems. Issues lead to incontinence

Answer 15

Pudendal Nerve (S2-S4)

Question 16

Nerve derived from the Anterior Divisions of S2-S4
-Supplies parasympathetic innervation to the pelvic viscera

Answer 16

Pelvic Splanchnic Nerve (S2-S4)

Question 17

Nerve derived from the Anterior Divisions of S3-S4
-Muscles occupy the pelvic inlet and support the viscera below.
-Makes up the pelvic diaphragm.

Answer 17

Nerve to Levator Ani

Question 18

Nerve derived from the Posterior Divisions of L4-L5; S1-S2
-Supplies motor to the Anterior leg, and sensory & motor to the dorsal surface of the foot, somewhat motor to the hamstring muscles

Answer 18

Common Peroneal Nerve (L4-L5; S1-S2)

Question 19

Only one that receives contributions from both Anterior (S2-S3) and Posterior (S1-S2) Divisions.

Answer 19

Posterior Femoral Cutaneous Nerve (S1-S2)