Lumbosacral Plexus Flashcards
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
Subcostal Nerve
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
Iliohypogastric Nerve
Derived from L1 VPR
-No divisions, derived from VPR itself
-Inferior Division
Ilioinguinal Nerve
Nerve that supplies the lateral thigh with sensation
-Derived from the Posterior Divisions of L2-L3
Lateral Femoral Cutaneous Nerve
Nerve that supplies sensation to the genitalia (males and females) and motor (males only).
-No divisions, derived from VPR itself (L1-L2)
Genitofemoral Nerve
-Derived from the Posterior Divisions of L2-L4
Femoral Nerve
-Present in about 9% of the population
-Derived from the Anterior Divisions of L3-L4
-Innervates the Pectineus Muscle
Accessory Obturator Nerve
-Derived from the Anterior Divisions of L2-L4
-Supplies the Pectineus Muscle (if no accessory present)
Obturator Nerve
A nerve mesh passing underneath the Psoas Major Muscle
Lumbar Plexus
Which nerves in the Lumbar Plexus come directly from the VPR itself? (no divisions)
-Subcostal nerve (T12)
-Iliohypogastric (L1)
-Ilioinguinal (L1)
-Genitofemoral (L1-L2)
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)
Sacral Plexus
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)
Lumbosacral Trunk
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
Tibial Nerve (L4-L5, S1-S3)
-Nerve derived from the Anterior Divisions of S2-S3
-Supplies sensation to the Posterior Thigh
Posterior Femoral Cutaneous Nerve (S2-S3)
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
Pudendal Nerve (S2-S4)