GA Lab 4 - Posterior Abdominal Wall Flashcards
What are the 3 parts of the abdominal prevertebral plexus? What fibers are in all? Describe each.
- Celiac: includes nerve fibers associated with the roots of the celiac trunk and superior mesenteric artery
- Aortic: from just below the superior mesenteric artery to the aortic bifurcation
- Superior hypogastric: at the bifurcation of the abdominal aorta, the abdominal prevertebral plexus continues inferiorly
How many sympathetic chain ganglia in abdomen?
Usually 4
How many lumbar splanchnics are there?
2-4
What is the abdominal prevertebral plexus a conduit for?
- Preganglionic sympathetic and visceral afferent fibers from the thoracic and lumbar splanchnic nerves
- Preganglionic parasympathetic and visceral afferent fibers from the vagus nerves
- Preganglionic parasympathetic fibers from the pelvic splanchnic nerves
What are prevertebral ganglia?
Collections of postganglionic sympathetic neuronal cell bodies in recognizable aggregations along the abdominal prevertebral plexus:
- Celiac ganglia
- SM ganglia
- Aorticorenal ganglia
- IM ganglia
Afferent pathway of kidneys and upper ureters? Referred pain area?
Least splanchnic nerve entering at T12
Referred pain: flanks and pubic region
Afferent pathway of hindgut and lower ureters? Referred pain area?
Lumbar splanchnics entering at L1/L2
Referred pain: flanks, groins, lateral and anterior thighs
Pathway of iliohypogastric nerve?
L1 => anterior surface of quadratus lomborum => pierces the transversus abdominis muscle => continues anteriorly around the body between the transversus abdominis and internal oblique muscles => above the iliac crest, a lateral cutaneous branch pierces the internal and external oblique muscles to supply the posterolateral gluteal skin + the anterior cutaneous branch continues in an anterior direction, piercing the internal oblique just medial to the ASIS as it continues in an obliquely downward and medial direction => becoming cutaneous, just above the superficial inguinal ring, after piercing the aponeurosis of the external oblique, it distributes to the skin in the pubic region
Which posterior abdominal wall nerve passes anteriorly to the iliacus?
Ilioinguinal nerve
Pathway of ilioinguinal nerve?
L1 => crosses part of the iliacus muscle on its way to the iliac crest => near the anterior end of the iliac crest, it pierces the transversus abdominis muscle => then pierces the internal oblique muscle and enters the inguinal canal => emerges through the superficial inguinal ring, along with the spermatic cord, and provides cutaneous innervation to the upper medial thigh, the root of the penis, and the anterior surface of the scrotum in men, or the mons pubis and labium majus in women
What is anterior to the genitofemoral nerves along its course?
Ureters
Pathway of genitofemoral nerve and its 2 branches?
L1 and L2 => passes downward in the substance of the psoas major muscle until it emerges on the anterior surface of the psoas major => then descends on the surface of the muscle
Genital branch: continues downward and enters the inguinal canal through the deep inguinal ring
Femoral branch: descends on the lateral side of the external iliac artery and passes posterior to the inguinal ligament, entering the femoral sheath lateral to the femoral artery => it pierces the anterior layer of the femoral sheath and the fascia lata to supply the skin of the upper anterior thigh
Pathway of the lateral cutaneous nerve of the thigh?
L2 and L3 => emerges from the lateral border of the psoas major muscle, passing obliquely downward across the iliacus muscle toward the ASIS => posterior to the inguinal ligament and enters the thigh
Motor function of obturator nerve?
Pelvic muscles
Motor function of femoral nerve?
Iliacus and muscles in thigh
