Dr Ahmed Fathalla Ibrahim LUMBAR PLEXUS LUMBAR PLEXUS

Dr. Ahmed Fathalla Ibrahim

LUMBAR PLEXUS

LUMBAR PLEXUS q. FORMATION: formed by anterior (ventral) rami of L 1, 2, 3 + part of L 4 q. SITE: in the substance of psoas major q. DISTRIBUTION: § Gives muscular branches to psoas major & quadratus lumborum from roots § Gives 6 branches

BRANCHES OF LUMBAR PLEXUS v. Four branches lateral to psoas major: § Iliohypogastric nerve (L 1) § Ilioinguinal nerve (L 1) § Lateral cutaneous nerve of thigh (L 2, 3) § Femoral nerve (L 2, 3, 4) v. One branch anterior to psoas major: § Genitofemoral nerve (L 1, 2) v. One branch medial to psoas major: § Obturator nerve (L 2, 3, 4)

BRANCHES OF LUMBAR PLEXUS § Iliohypogastric: superficial to QL, QL passes through anterior abdominal wall, supplies TA, IO & EO + skin of lower part of anterior abdominal wall § Ilioinguinal: superficial to QL, passes through inguinal canal, supplies TA, IO & EO + skin of external genitalia § Lateral cutaneous nerve of thigh: superficial to iliacus, iliacus deep to inguinal ligament, supplies skin of lateral surface of thigh

BRANCHES OF LUMBAR PLEXUS § Femoral nerve: between psoas major & iliacus, iliacus supplies iliacus (in abdomen), deep to inguinal ligament, supplies muscles of anterior compartment of thigh § Genitofemoral nerve: divides into: 1. Genital branch: enters spermatic cord, supplies cremaster muscle 2. Femoral branch: supplies skin of upper part of front of thigh

BRANCHES OF LUMBAR PLEXUS § Obturator nerve: anterior to sacroiliac joint (behind common iliac vessels), vessels) supplies pelvic peritoneum, passes through obturator canal, canal supplies muscles of medial compartment of thigh

SYMPATHETIC TRUNK & AORTIC PLEXUSES

ABDOMINAL PART OF SYMPATHETIC TRUNK q. BEGINNING: continuation of thoracic part after passing behind medial arcuate ligament q. TERMINATION: continues in the pelvis by passing behind common iliac vessels q. COURSE: runs along medial border of posas major 1) Left: to left side of abdominal aorta 2) Right: behind IVC

ABDOMINAL PART OF SYMPATHETIC TRUNK q NUMBER OF GANGLIA: 4 q BRANCHES: 1. White rami communicantes (preganglionic & visceral afferent sensory nerve fibers): join upper 2 ganglia to L 1 & L 2 2. Gray rami communicantes (postganglionic nerve fibers) to blood vessels & sweat glands): join each ganglion to corresponding lumbar nerve 3. Fibers join aortic plexuses & share in formation of superior hypogastric plexus

AORTIC PLEXUSES v. AORTIC PLEXUS: around abdominal aorta v. CELIAC PLEXUS: formed of 2 ganglia connected by fibers around celiac artery v. RENAL PLEXUS: around renal artery v. SUPERIOR MESENTRIC PLEXUS: around superior mesenteric artery v. INFERIOR MESENTERIC PLEXUS: around inferior mesenteric artery

AORTIC PLEXUSES q FORMATION: each plexus is formed of: 1. Preganglionic sympathetic fibers from greater & lesser splanchnic nerves that usually relay in celiac ganglia 2. Postganglionic sympathetic fibers from celiac ganglia & sympathetic trunks 3. Preganglionic parasympathetic fibers from vagus or pelvic splanchnic nerves ( in case of inferior mesenteric plexus) 4. Visceral afferent fibers N. B. : Sympathetic fibers from plexuses & sympathetic trunks form superior hypogastric plexus below bifurcation of abdominal aorta

LYMPH NODES

PREAORTIC LYMPH NODES q. CELIAC L. N. : around celiac trunk • Afferents: from foregut q. SUPERIOR MESENTERIC L. N. : around superior mesenteric artery • Afferents: from midgut q. INFERIOR MESENTERIC L. N. : around inferior mesenteric artery • Afferents: from hindgut v. EEFERENTS FORM THE INTESTINAL LYMPH TRUNK

LATERAL AORTIC LYMPH NODES • Also called: “paraaortic or lumbar L. N. ” • AFFERENTS: from kidneys, gonads, uterine tubes, fundus of uterus, anterior abdominal wall (deep lymphatics), common iliac L. N. • EFFERENTS: form RIGHT & LEFT LUMBAR LYMPH TRUNKS

CYSTERNA CHYLI & THORACIC DUCT q CYSTERNA CHYLI: § An elongated lymph sac (opposite L 1 & L 2), on the right side of abdominal aorta § Afferents: 1) Intestinal lymph trunk 2) Right & left lumbar lymph trunks 3) Lymphatics from thorax q THORACIC DUCT: § Upward continuation of cysterna chyli § Ascends to thorax through aortic opening