The Abdomen Stuart M Bunt Functional Anatomy 212 T290 Entire gut laid out T318 barium meal/small intestines T315 overall layout of gut A1 Embryonic plate, gastrulation/streak MF10 embryological devt of mesentaries T13 gut rotation T14 gut rotation cont. T8 situs invertus T39 omental bursa T311 greater and lesser sac MG6(?) fusion of trans mesocolon with omentum T38 retroperitoneal attachments (post abd. wall) T160 suspensory ligament of duodenum (of Treitz) T37 duodenal pockets/folds T43 ileocecal fold (put volvulus etc here from next lecture slides?) Functional Anatomy 212

Overview

Embryology Revision Foregut, Midgut and Hindgut suspended by the dorsal mesentary, initially straight Ventral mesentary connects stomach and ant. abd. wall, rest of gut free anteriorly Mesentary supplies blood and nerves to gut between layers of peritoneum Complex adult layout due to 270o rotation

Blood Supply to Abdominal Organs Foregut Celiac trunk Midgut Superior mesenteric artery Hindgut Inferior mesenteric artery Rectum Internal iliac artery (pudendal and rectal arteries)

Stomach Variable size and shape, distensible J shaped related to body form Lesser and greater curvature gastroesophageal junction fundus,cardiac part, body, pyloric part pyloric antrum and sphincter rugae and gastric pits

Blood Supply of Stomach

Superior Mesenteric Artery Territory

Inferior mesenteric artery territory

Venous system Portal Vein Hepatic Veins Inf. Vena Cava Splenic vein inferior mesenteric vein Superior mesenteric vein Gastric veins Hepatic Veins Inf. Vena Cava

Anastomoses

Stomach rotates and distends Front Dorsal Mesentary Ventral Mesentary Back Splenic tissue Omentum Epiploic Foramen

Omentum

Under the OMENTUM

The Peritoneal cavity is divided in two Rotation of stomach forms the greater omentum (allows stomach distension and infection control) Omental bursa or Lesser sac is inside omentum (a potential space) Lesser omentum runs from stomach to liver (note free lower border above epiploic foramen contains portal vein, hepatic artery and bile duct Falciform ligament runs from liver to ant abd. wall

Mesenteries are important:- Paracolic gutters channel fuid Stop herniation due to bipedal posture Supply blood/nerves Sensitive to stretch Contain infection Useful in surgery

On return some gut fuses with posterior wall Diaphragm 1 2 Duo. Asc. Colon Desc. Colon 3 1.lienorenal lig. 2.trans. mesocolon 3.mesentary proper 4.mes. of sig. colon 4 Rectum

Retro-peritoneal

Oesophagus 10 inches from pharynx to stomach narrow at cricoid cartilage where left bronchus crosses oesophageal hiatus in diaphragm mucous membrane folded (normally collapsed) stratified squamous epithelium striated above smooth below trachea on right, lower aorta on left medial to L. lung, behind left atrium

Duodenum first 12 inches of gut four parts form C shape duodenal cap radiologically identified, ulcers form here mobile descending part pancreatic and bile ducts horizontal part crosses psoas, IVC and aorta crossed by mesentery, sup mesen. art. ascending part

Jejunum 2/5ths of small intestine gradual transition to ileum many small villi increasing numbers of lymph nodules no submucosal glands lacteals in each villus columnar epithelium

Ileum distal 3/5ths of intestine narrower, thinner, less vascular, slower, more fat and arterial arcades in mesentery than jejunum. Peyer’s patches of lymphoid tissue

Colon ascending colon retroperitoneal right colic or hepatic flexure transverse colon (mesocolon) droops towards pelvis? left colic or splenic flexure descending colon retroperitoneal pelvic or sigmoid colon S shaped

Colonoscopy Barium enema outlines structures on X-rays

Appendix

The Liver Largest Gland (one of largest organs) Right upper abdomen under diaphragm Grows as outgrowth of gut plus mesoderm Diaphragmatic surface Visceral surface down and left related to stomach, duodenum, r. kidney, r. colonic flexure bears gall bladder

Biliary System R and L Hepatic ducts Common hepatic duct Joined by cystic duct (to gall bladder) Forms bile duct (common bile duct) Gall Bladder body and fundus, salts and water absorbed store for bile, released in response to cholecystokinin

Pancreas

Pancreas Head in concavity of duodenum body across vertebrae tail reaches the spleen pancreatic duct (+ accessory?) ampulla duodenal papilla

Spleen

The Spleen Lies in left hypochondriac region between gastric fundus and diaphragm at level of 9th-10th rib (not normally palpable) Soft, friable, highly vascular, dark purple Diaphragmatic surface convex and smooth facing diaphragm Visceral surface gastric, renal, pancreatic and colic impressions Slides T74 pancreas from back (bile duct) T75 annular pancreas formation T83 annular pancreas T82 ducts inside annular pancreas THESE SHOULD HAVE GONE IN LAST LECTURE? T73 splenic artery T86 splenic pedicle and accessory splenicules(Need slide of development?) T87 splenic artery, short gastrics and left gastro-epiploic T159 point of attachment of lienorenal ligament T88 hilum of spleen T89 many sorts of splenic hilum arteries T197 Distribution of Vagus nerve in abdomen T202 entrance points of splanchnic nerves into abdomen T203 ceoliac plexus T204 lumbar sympathetic ganglia T206 hypogastric plexus T207 general path of sympathetics to viscera (too complicated?) (Need more/better autonomic slides next year?)

The Spleen (2) Hilum of spleen long fissure through which vessels and nerves pass Suspended from stomach by gastrolienal ligament (contains short gastric and left gastro-epiploic branches of spenic artery) Suspended from posterior abdominal wall by lienorenal ligament Covered by adherent peritoneum

Relationship to the Spleen

Kidneys In fat capsule Suprarenal glands superiorly Direct Arterial and venous supply

Kidney Internal Structure Renal pyramids between renal columns Renal Cortex Renal papillae drain into minor calix Major calix join to form renal pelvis Ureter as outlet

Kidneys External View Artery - Vein - Ureter

Relationships of the Kidneys