GI Flashcards
Peritoneum (aka serous membrane)
Layer of serosa that lines the abdominal cavity. Has two portions: parietal and visceral
Parietal Peritoneum
Portion that lines body wall
Visceral peritoneum
Portion that lines the organs
Mesentery
fold of peritoneum layers (parietal & visceral) through which nerves, vessels and lymphatics travel to/from organs; also anchors organs (GI organs) to the posterior wall of the abdomen
Intraperitoneal
organs covered in peritoneum & suspended from body wall by mesentery such as stomach, liver, gallbladder, spleen, etc.
Primary Retroperitoneal
organs develop and remain outside the peritoneal cavity; not associated wtih mesentery (kidneys, adrenal glands, aorta, IVC, bladder, prostate, vagina)
Secondary Retroperitoneal
organs develop in mesentery, only part of the organ surface is covered by peritoneum, and organs are separated from body wall by bloodless plane such as pancreas, duodenum (2nd & 3rd), ascending and descending colon.
Hepatorenal (Morrison’s) pouch
located behind the liver, located between the liver and the right kidney. It is a potential space that can be filled with fluid in abnormal circumstances.
Rectovesical/ Rectouterine (Douglas) pouch
Rectovesical- a potential space between the rectum and the bladder;
Rectouterine- potential space between the bladder and uterus
Both can be filled with fluid under abnormal circumstances
Dorsal Mesentery
in adults, it is the portion that attaches to the greater curvature of the stomach
Ventral mesentery
Present in embryos between the body wall and liver and the liver and stomach; the only remnants of it are the falciform ligament and the lesser omentum
What makes up the Foregut?
Esophagus, stomach, duodenum (1st & 2nd)
Develop in association: liver, gallbladder, and spleen
What does Celiac Trunk supply?
Foregut (esophagus, stomach, duodenum (1st &2nd), liver, gallbladder, and spleen
Branches into: splenic artery, left gastric artery, common hepatic artery
What makes up the midgut?
Duodenum (3rd & 4th), Jejunum, Ileum, Cecum, Appendix, Ascending colon, Transverse colon
This is where most of the absorption of nutrients & water occur
Superior Mesenteric Artery supplies?
Midgut (Duodenum 3rd & 4th), Jejunum, Ileum, Cecum, Appendix, Ascending colon, and Transverse colon)
Originates off aorta from L1; branches into: inferior pancreaticoduodenal artery, jejunum and illeum arteries, ileocolic artery, right colic artery, and middle colic artery
What makes up the Hindgut?
Transverse colon, Descending colon, Sigmoid colon, and rectum to ano-rectal line
Inferior Mesenteric Artery supplies?
Hindgut (Transverse colon, Descending colon, Sigmoid colon, Rectum to ano-rectal line)
Originates off aorta from L3; branches into the left colic artery, sigmoid artery, and superior rectal artery
Foregut Venous Drainage
Splenic vein & gastric vein will drain to portal vein
Midgut Venous Drainage
Superior mesenteric vein will drain to portal vein
Hindgut Venous Drainage
Inferior mesenteric vein will drain to portal vein
Lesser Sac
A recess of the peritoneal cavity that lies between the stomach and posterior abdominal wall.
Opening to the lesser sac is on the right side called Foramen of Winslow.
Foramen of Winslow
opening to the lesser sac on the right side (only opening)
Greater Omentum
a large apron-like fold of visceral peritoneum (fat & tissue) that hangs down from the stomach and drapes over the transverse colon, small intestines, and descending colon.
Has some ability to protect organs in region by wrapping itself around a tumor or something if need be.
Lesser Omentum
is between the inferior liver to the lesser curvature of the stomach. It contains the falciform ligament, the hepatogastric ligament, and the hepatoduodenal ligament
Hepatogastric ligament
connects the liver to the lesser curvature of the stomach; basically lays over the lesser omentum
Hepatoduodenal ligament
Contains proper hepatic artery, common bile duct, and hepatic portal vein
Esophagus
muscular tube that brings food and liquid down from pharynx to stomach; pierces the diaphragm at T10 level.
Blood supplied by esophageal branches of aorta & left gastric artery of celiac trunk)
Veinous drainage by esophagus branches of azygos vein & left gastric vein to portal vein
Stomach
functions as a blender and reservoir for food to be mechanically and chemically prepared for digestion;
Blood is supplied via branches off celiac trunk (which branch off aorta): left and right gastric arteries to the lesser curvature, right and left gastro-omental arteries to the greater curvature, and short gastric arteries to the fundus & upper stomach
Venous drainage: right and left gastric veins from lesser curvature to portal vein, short gastric and left gastro-omental into splenic vein, right gastro-omental into superior mesenteric vein
Celiac Trunk
branches off aorta and supplies the foregut
Spleen
functions as a lymphatic organ (proliferation), immune surveillance, recycles old RBCs and platelets and is reservoir of RBCs & platelets
most vascular organ; vulnerable to injury but protected by lower left ribcage; held in place by gastrosplenic ligament & splenorenal ligament
blood supplied by splenic artery which branches off celiac trunk
venous drainage by splenic vein to portal vein
Duodenum
Is the first part of the small intestine, extending from the pylorus to the duodenojejunal junction. Functions to receive chyme mixed with stomach acid, enzymes and digestive juices to aid in digestion There are four parts: 1st- superior (intraperitoneal) 2nd-descending (retroperitoneal) 3rd- horizontal (retroperitoneal) 4th- ascending (intraperitoneal)
Blood supplied by: celiac trunk (superior pancreaticoduodenal artery) and SMA (inferior pancreaticoduodenal arteries)
Venous drainage: parallel arteries that drain into the splenic vein/ SMV
Ligament of Treitz
suspensory ligament that connects the diaphragm to the 4th part of duodenum
Sphincter of Oddi
Releases bile into the 2nd part of the duodenum.
Bile is produced?
Bile is produced in the liver, which will go down the left and right hepatic ducts into the common hepatic duct and all the way down to the sphincter of Oddi. If sphincter closed then it will go back up common bile duct and pool into the gallbladder for storage.
Pancreas
is an accessory digestive gland that produces pancreatic juices which enters into the duodenum via main and accessory pancreatic ducts. Also secretes insulin & glucagon
Located posterior to stomach. Has 5 parts: Head, Uncinate process, Neck, Body, and Tail.
Blood supplied by pancreatic arteries ( from splenic artery) & superior and inferior pancreaticoduodenal artery
Venous drainage: pancreatic veins drain to splenic veins which drain to portal vein.
Portal Triad
Consists of the portal vein, proper hepatic artery, and common bile duct. Travels within the hepatoduodenal ligament
Falciform Ligament
separates the left and right love of the liver
Caudate Lobe
Located within the right lobe; has its own blood supply and drainage so can functionally independently
Ligamentum Teres
located in the liver right next/underneath the falciform ligament
Liver
Functions to process nutrients from GI tract, store glycogen, secretor of bile, detoxification, & phagocytosis
blood supply:
celiac trunk–>common hepatic artery–> hepatic artery proper–> right and left hepatic arteries
Venous drainage:
right, intermediate, left hepatic veins drain into IVC
Gallbladder
When bile is not used, it is stored and concentrated in the gallbladder.
Blood supplied by: cystic artery (branches from right hepatic artery)
Venous drainage: cystic veins which drains to portal vein or to liver
Tenaie Coli
the middle white part that runs along the large intestine; it is a band of smooth muscle
Cecum
blind intestinal pouch at the most proximal end of the large intestine; it is joined by the Ileum; gives rise to the appendix
Appendix
Comes off of the cecum; has its own supply of mesentery and artery
Large intestine
This is where absorption of water from foods that are going to be shitted occurs.
Blood supplied by: SMA branches (ileocolic artery, right colic artery, middle colic artery) which are all joined together via marginal artery
Venous drainage: drain to the SMV–>portal vein
Superior rectal artery
supplied 2/3 of the anal canal and last branch off of the IMA
Suprarenal arteries
There are three: superior, middle, and inferior
Superior: branches off of the inferior phrenic artery and call these little arteries connect directly to the adrenal gland on top of kidney
Middle: branches off of the abdominal aorta and connects also to the adrenal gland
Inferior: branches off of the renal artery and connects to the underside of adrenal gland
Renal Artery
Comes off the abdominal aorta at the same level as the SMA
Umbilical artery
Branches off of the internal iliac artery
Where is the Sphincter of Oddi located?
2nd part of the duodenom
Where does the bile and pancreatic enzymes secrete into?
2nd part of the duodenom
