Lumbosacral plexus Flashcards
What are the roots of the iliohypogastric nerve?
T12, L1
What is the trajectory of the iliohypogastric nerve?
emerges from upper lateral border of psoas major
crosses obliquely behind lower pole of kidney + in front of quadratus lumborum
runs to iliac crest across quadratus lumborum muscle of posterior abdominal wall
perforates transversus abdominis
divides into its terminal branches.
What are the motor functions of the iliohypogastric nerve?
Innervates internal oblique + transversus abdominis.
What is the sensory function of the iliohypogastric nerve?
Innervates pubic region
What is the root of the ilioinguinal nerve?
L1
What is the trajectory of the ilioinguinal nerve?
follows same anatomical course as larger iliohypogastric nerve->passes obliquely across quadratum lumborum
enters tranversus abdominis near anterior end of iliac crest (there can be easily pierced to perform local anaesthesia to the inguinal canal)
After innervating muscles of anterior abdominal wall
innervates upper middle thigh + suprapubic skin.
What are the motor functions of the ilioinguinal nerve?
Innervates internal oblique + transversus abdominis.
What is the sensory function of the ilioinguinal nerve?
Innervates skin on upper middle thigh.
- In males: also supplies skin over root of penis + anterior scrotum.
- In females: supplies skin over mons pubis + labia majora.
What are the roots of the genitofemoral nerve?
L1, L2
What is the trajectory of the genitofemoral nerve?
descends under peritoneum on psoas major
crosses obliquely behind ureter
Above inguinal ligament quickly divides into genital branch + femoral branch.
What are the sensory functions of the genitofemoral nerve?
innervates skin of anterior scrotum (in males) or skin over mons pubis + labia majora (in females).
Femoral branch innervates skin on upper anterior thigh.
What is a specificity of the lateral femorsl cutaneous nerve?
- purely sensory function.
What are the roots of the lateral femoral cutaneous nerve?
L2, L3
WHat is the trajectory of the lateral femoral cutaneous nerve?
emerges lateral to psoasenters thigh under lateral aspect of inguinal ligament
providing cutaneous innervation to the skin there
supplies parietal peritoneum in iliac fossa
then passes under inguinal ligament
over Sartorius muscle into thigh
divides into two branches: anterior + posterior branches
What is Meralgia paresthetica?
tingling, numbness and burning pain in your outer thigh due to obesity, pregnancy causing compression of lateral femoral cutaneous nerve.