Posterior Abdominal Wall Flashcards
Name the bony elements of the posterior abdominal wall
- Lumbar vertebrae
- Wing of the ilium
- Sacrum
Name the muscles of the posterior abdominal wall
- quadratus lumborum
- psoas major
- psoas minor
- iliacus
Name the 7 nerves of the lumbar plexus
- subcostal
- iliohypogastric
- ilioinguinal
- genitofemoral
- obturator
- lateral femoral cutaneous
- femoral
Most nerves of the posterior abdominal wall pass through ____
Psoas major
What nerve supplies the skin in the suprapubic region?
iliohypogastric (L1)
The lumbar plexus is composed of what spinal levels?
T12-L4
What nerve supplies skin along the proximomedial thigh, root of penis, upper scrotum (Mona pubis) and labia majora?
ilioinguinal (L1)
What nerve supplies cremaster and scrotal skin?
Genital branch of genitofemoral n
What nerve supplies skin over the femoral triangle?
Femoral branch of genitofemoral n
What nerve supplies skin over the anterior gluteal region and greater trochanter?
Subcostal n (T12)
What nerve supplies skin over the lateral thigh?
Lateral femoral cutaneous n (L2-L3)
What nerve supplies skin medially above the knee?
Obturator (L2-L4)
The obturator nerve emerges from the… and enters the thigh via the ____
Medial border of Psoas major
Obturator foramen
What does the obturator nerve innervate?
- adductors of thigh
- skin medial & above knee
The femoral nerve emerges from the… and separates into…
- lateral border of psoas major
- ant femoral cutaneous branches & saphenous n near the inguinal ligament
What does the femoral nerve innervate?
- knee extensors
- thigh flexors
- skin of anteriomedial thigh
The ____ brings L4 to L5 nerve roots into the lumbosacral plexus
Lumbosacral trunk
What spinal levels contain axons for preganglionic sympathetic neurons that leave the spinal cord via ventral roots?
T1-L2
Preganglionic sympathetic neurons that leave the spinal cord via ventral roots pass through the ____
White communicating branches (white rami communicans)
Gray rami communicans pass from ____ to ____
Paravertebral ganglion
Adjacent ventral rami
The thoracic sympathetic trunk passes under the ____ and becomes the ____
Medial Arcuate ligament
Lumbar sympathetic trunk
What divisions are in the sciatic nerve?
Anterior & posterior
(L4-S3)
Describe the path of the sciatic nerve
- exits via greater sciatic foramen
- emerges from inferior border of piriformis
- runs into popliteal fossa
- branches into tibial & common fibular nerves
What divisions of the lumbosacral plexus make up the tibial division of the sciatic nerve?
Anterior
What divisions of the lumbosacral plexus make up the common fibular division of the sciatic nerve?
Posterior
What divisions of the lumbosacral plexus make up the posterior femoral cutaneous nerve?
Anterior & posterior
Describe the path of the posterior femoral cutaneous nerve
- exits via greater sciatic foramen
- runs deep to gluteus maximus & emerges from inferior border
Which nerves are derived from the anterior division of the lumbosacral plexus?
- tibial
- n to quadratus femoris
- n to obturator internus
- pudendal n
- n to Levator ani & coccygeus
Which nerves are derived from the posterior division of the lumbosacral plexus?
- common fibular
- superior gluteal
- inferior gluteal
- n to piriformis
- perforating cutaneous
Name 2 nerves that have mixed anterior and posterior divisions of the lumbosacral plexus
Sciatic
Posterior femoral cutaneous
The inferior cluneal nerves contain branches of ____ indicating…
Ventral rami
Lower extremity (appendicular skeleton) begins
The superior and middle cluneal nerves contain branches of ____
Dorsal rami
What spinal levels are in the lumbosacral plexus?
L4-S3
