L 24-25 Gastrointestinal System I & II – Vocabulary Flashcards

Vocabulary flashcards covering major anatomical terms, blood supply, innervation, peritoneal structures, and clinical correlations of the gastrointestinal system as presented in the lecture notes.

Foregut

GI region from distal esophagus to major duodenal papilla; supplied by celiac trunk, vagus nerve, and drains to celiac lymph nodes.

Midgut

GI region from major duodenal papilla to left colic flexure; supplied by superior mesenteric artery, vagus nerve, and drains to superior mesenteric lymph nodes.

Hindgut

GI region from left colic flexure to pectinate line of anal canal; supplied by inferior mesenteric artery, pelvic splanchnic nerves, and drains to inferior mesenteric lymph nodes.

Celiac Trunk

First unpaired branch of abdominal aorta that supplies foregut organs via left gastric, splenic, and common hepatic arteries.

Superior Mesenteric Artery (SMA)

Artery that supplies midgut structures including pancreas, small intestine, cecum, ascending and transverse colon.

Inferior Mesenteric Artery (IMA)

Artery that supplies hindgut structures including descending and sigmoid colon, rectum, and upper anal canal.

Celiac Ganglia

Sympathetic ganglia that relay preganglionic fibers to foregut organs, producing decreased motility and vasoconstriction.

Superior Mesenteric Ganglia

Sympathetic ganglia that innervate midgut organs, reducing secretion and motility.

Inferior Mesenteric Ganglia

Sympathetic ganglia that innervate hindgut organs via lumbar splanchnic nerves.

Pelvic Splanchnic Nerves

Parasympathetic nerves (S2-S4) that supply hindgut distal to left colic flexure and pelvic organs.

Vagus Nerve (CN X)

Provides parasympathetic innervation to foregut and midgut, increasing GI motility and secretion.

Parietal Peritoneum

Outer serous membrane lining the body wall; somatic innervation makes it highly pain-sensitive.

Visceral Peritoneum

Inner serous layer covering abdominal organs; visceral innervation produces referred pain.

Peritoneal Cavity

Potential space between parietal and visceral peritoneum; may accumulate fluid in ascites.

Mesentery

Double layer of peritoneum suspending an intraperitoneal organ and conveying vessels, nerves, and lymphatics.

Transverse Mesocolon

Mesentery attaching transverse colon to posterior abdominal wall.

Sigmoid Mesocolon

Peritoneal fold anchoring sigmoid colon and containing its vessels.

Mesoappendix

Peritoneal fold connecting vermiform appendix to ileum and cecum, carrying appendicular artery.

Mesentery Proper

Fan-shaped mesentery attaching jejunum and ileum to posterior wall.

Peritoneal Ligament

Double layer of peritoneum connecting organs to each other or to the body wall, e.g., falciform ligament.

Hepatogastric Ligament

Part of lesser omentum connecting liver to lesser curvature of stomach.

Hepatoduodenal Ligament

Right free edge of lesser omentum containing the portal triad.

Gastrocolic Ligament

Portion of greater omentum connecting stomach to transverse colon.

Falciform Ligament

Peritoneal ligament attaching liver to anterior abdominal wall and containing ligamentum teres hepatis.

Omentum

Double layer of peritoneum connecting stomach to other organs; divided into greater and lesser omenta.

Lesser Omentum

Ventral mesentery derivative connecting liver to stomach and duodenum via hepatogastric and hepatoduodenal ligaments.

Greater Omentum

Large apron-like fold of peritoneum hanging from greater curvature, containing gastrocolic, gastrosplenic, and gastrophrenic ligaments.

Omental Bursa (Lesser Sac)

Posterior peritoneal compartment behind the stomach; communicates with greater sac via omental (epiploic) foramen.

Omental (Epiploic) Foramen

Opening posterior to hepatoduodenal ligament that links greater and lesser sacs.

Intraperitoneal Organ

Organ almost completely covered by visceral peritoneum and suspended by a mesentery, e.g., stomach, spleen.

Primary Retroperitoneal Organ

Organ that never had a mesentery, e.g., kidneys, aorta, IVC.

Secondary Retroperitoneal Organ

Organ that lost its mesentery during development, e.g., pancreas (except tail), ascending and descending colon.

Portal Vein

Formed by union of splenic and superior mesenteric veins; carries nutrient-rich blood to liver.

Portosystemic Anastomosis

Connection between portal and systemic venous systems; sites include esophagus, umbilicus, and rectum.

Esophageal Varices

Dilated submucosal veins at lower esophagus due to portal hypertension; risk of fatal bleeding.

Caput Medusae

Radiating peri-umbilical veins caused by portal hypertension through para-umbilical anastomoses.

Hemorrhoids

Varicosities of rectal venous plexuses; internal (painless) or external (painful) depending on location relative to pectinate line.

Common Hepatic Artery

Branch of celiac trunk that gives rise to gastroduodenal and proper hepatic arteries.

Proper Hepatic Artery

Supplies liver; divides into right and left hepatic arteries, right often giving off cystic artery.

Splenic Artery

Tortuous branch of celiac trunk supplying spleen, pancreas, and stomach via short gastric and left gastro-omental arteries.

Left Gastric Artery

Smallest celiac branch; supplies lesser curvature and esophageal branches.

Right Gastric Artery

Typically branch of proper hepatic artery anastomosing with left gastric on lesser curvature.

Right Gastro-Omental Artery

Branch of gastroduodenal artery supplying greater curvature and anastomosing with left gastro-omental artery.

Left Gastro-Omental Artery

Branch of splenic artery supplying greater curvature of stomach.

Short Gastric Arteries

Branches of splenic artery supplying fundus of stomach without significant anastomoses.

Stomach Cardia

Region around esophageal opening; contains physiological sphincter preventing reflux.

Fundus

Dome-shaped superior part of stomach above cardiac notch.

Body of Stomach

Largest central region between fundus and pyloric antrum.

Pyloric Sphincter

Thickened circular muscle controlling gastric emptying into duodenum.

Omental Bursa Posterior Wall

Structures deep to stomach: pancreas, left kidney, spleen, aorta, IVC.

Ascites

Pathologic accumulation of fluid within peritoneal cavity.

Spleen

Largest lymphoid organ; intraperitoneal in left hypochondrium; filters blood and stores platelets.

Splenorenal Ligament

Peritoneal fold between spleen and left kidney containing splenic vessels and tail of pancreas.

Gastrosplenic Ligament

Peritoneal fold connecting stomach to spleen carrying short gastric vessels.

Segmental Splenic Arterial Supply

Splenic artery divides into 4-5 terminal branches at hilum creating avascular planes for surgery.

Bare Area of Liver

Posterior hepatic surface not covered by peritoneum, in contact with diaphragm.

Ligamentum Teres Hepatis

Fibrous remnant of fetal left umbilical vein in free edge of falciform ligament.

Ligamentum Venosum

Fibrous remnant of fetal ductus venosus located in left sagittal fissure of liver.

Portal Triad

Bile duct (anterolateral), proper hepatic artery (anteromedial), and portal vein (posterior) within hepatoduodenal ligament.

Caudate Lobe

Posterior hepatic lobe functionally separate, receiving blood from right and left hepatic arteries and draining directly into IVC.

Quadrate Lobe

Anterior inferior lobe of liver located between gallbladder fossa and ligamentum teres.

Hepatic Veins

Right, middle, and left veins draining liver into IVC at caval opening.

Gallbladder

Intraperitoneal sac on visceral liver surface that stores and concentrates bile.

Cystic Duct

Channel connecting gallbladder to common hepatic duct; joins to form bile duct.

Cystohepatic Triangle (of Calot)

Space bounded by cystic duct, common hepatic duct, and liver; contains cystic artery.

Cholelithiasis (Gallstones)

Crystallized cholesterol deposits in gallbladder or biliary ducts causing biliary colic and potential jaundice.

Biliary Duct System

Network of hepatic ducts, common hepatic duct, cystic duct, and bile duct delivering bile to duodenum.

Ampulla of Vater

Dilated junction of bile and main pancreatic ducts entering duodenum at major papilla; regulated by sphincter of Oddi.

Pancreas

Secondarily retroperitoneal gland with exocrine (digestive enzymes) and endocrine (insulin, glucagon) functions.

Pancreatic Head

Widest part nestled in duodenal C-loop; includes uncinate process posterior to SMA.

Pancreatic Tail

Intraperitoneal segment within splenorenal ligament near splenic hilum.

Main Pancreatic Duct

Duct of Wirsung uniting with bile duct to form hepatopancreatic ampulla.

Accessory Pancreatic Duct

Duct of Santorini draining pancreatic head to minor duodenal papilla.

Anterior & Posterior Superior Pancreaticoduodenal Arteries

Branches of gastroduodenal artery supplying proximal duodenum and pancreatic head.

Anterior & Posterior Inferior Pancreaticoduodenal Arteries

Branches of SMA supplying distal duodenum and pancreatic head; anastomose with superior counterparts.

Suspensory Ligament of Duodenum

Ligament of Treitz anchoring duodenojejunal flexure to right crus of diaphragm.

Major Duodenal Papilla

Opening in second duodenal part where bile and main pancreatic ducts empty; marks foregut-midgut transition.

Minor Duodenal Papilla

Site where accessory pancreatic duct enters second part of duodenum.

Jejunum

Proximal 2/5 of small intestine beyond duodenum; thick walls, long vasa recta, few arterial arcades.

Ileum

Distal 3/5 of small intestine; thinner walls, short vasa recta, many arcades, contains Peyer’s patches.

Peyer’s Patches

Aggregated lymphoid nodules in ileal mucosa important for immune surveillance.

Meckel’s Diverticulum

Vestigial remnant of vitelline duct; ileal blind pouch 2 feet from ileocecal valve, may mimic appendicitis.

Vasa Recta

Straight arterial branches from intestinal arcades supplying jejunum and ileum.

Teniae Coli

Three longitudinal smooth muscle bands along large intestine excluding appendix and rectum.

Haustra

Sacculations of large intestine formed by tonic contractions of teniae coli.

Epiploic Appendices

Peritoneal fat tags projecting from serosa of colon.

Cecum

Blind intraperitoneal pouch in right iliac fossa receiving ileum via ileocecal orifice.

Vermiform Appendix

Narrow blind diverticulum with lymphoid tissue attached to cecum; blood supply via appendicular artery.

Ascending Colon

Secondarily retroperitoneal segment from cecum to right colic flexure.

Transverse Colon

Intraperitoneal segment suspended by transverse mesocolon; ends at left colic flexure.

Descending Colon

Secondarily retroperitoneal segment from left colic flexure to sigmoid colon.

Sigmoid Colon

Intraperitoneal S-shaped colon attached by sigmoid mesocolon; continues as rectum.

Marginal Artery (of Drummond)

Continuous arterial arcade along colon formed by SMA and IMA branches, providing collateral circulation.

Superior Rectal Artery

Terminal branch of IMA supplying rectum above pectinate line.

Middle Rectal Artery

Branch of internal iliac artery supplying mid-rectum and anastomosing with superior and inferior rectal arteries.

Inferior Rectal Artery

Branch of internal pudendal artery supplying anal canal below pectinate line.

Pectinate Line

Embryologic junction in anal canal separating endoderm (visceral) from ectoderm (somatic) territory, differing in blood supply, innervation, and lymph drainage.

Anal Columns

Longitudinal mucosal folds in upper anal canal containing terminal branches of superior rectal vessels.

Anal Valves

Semilunar folds uniting inferior ends of anal columns forming bases of anal sinuses.

Internal Anal Sphincter

Involuntary smooth muscle continuation of circular rectal layer controlled by autonomics.