The gastrointestinal tract (up to the end) Flashcards
What is the peritoneal relationship of the stomach?
totally intraperitoneal
What is the angular incision of the stomach?
An indentation on the lesser curvature that marks the junction with the pylorus
What attaches the cardia to the diaphragm?
Gastrophrenic ligament
What level can the fundus reach?
level of the 5th IC space
What is the angle of His?
Formed on the greater curvature by the cardial notch / incision, prevents reflux
What are the 2 parts of the pyloric part of the stomach?
- Pyloric antrum
- Pyloric canal
What is the pylorus?
Sphincteric region, with a thick circular layer of smooth muscle named the pyloric sphincter.
What happens to the interior of the stomach when there is contraction (swallowing)?
Formation of a tunnel, Magen Strasse with longitudinal ridges called gastric folds/rugae
What are the 3 parts of the muscular layer of the stomach?
- inner circular layer
- outer longitudinal layer
- innermost oblique layer (only from cardia to angular notch)
What is the gastrosplenic ligament a continuation of, and what does it continue as?
continuation of gastrocolic, continues as phrenicosplenic
What are the 6 arteries that supply the stomach?
- Left gastric (branch of celiac trunk)
- Right gastric (branch of proper hepatic)
- Posterior gastric (from splenic)
- Short gastric arteries (form splenic)
- Left gastro-epiploic (from splenic)
- Right gastro-epiploic (from gastroduodenal)
What are the 4 lymph nodes for the stomach?
- gastric lymph nodes
- pancreatico-splenic
- pyloric / gastroomental
- pancreaticoduodenal
What is the parasympathetic innervation of the stomach?
anterior and posterior vagal trunks + celiac plexus
What is the sympathetic innervation of the stomach?
celiac plexus of T6-T9 through greater splanchnic nerves
At what level is the duodenojejunal junction?
at the level of L2
What can we find at the duodenojejunal junction?
The ligament of Treitz, which attaches is to the crux of the diaphragm
What is the duodenal ampulla?
connection of pylorus with the duodenum in the superior horizontal part, that is dilated
What is the peritoneal relation of the superior horizontal part of the duodenum?
Intraperitoneal
What attaches at the ampulla of the duodenum?
The hepatoduodenal ligament
What is the name of the opening and sphincter of the hepatopancreatic ampulla in the duodenum?
Vater’s papillae, with Oddi sphincter
What opens into the descending duodenum?
- Hepatopancreatic ampulla (common bile duct + main pancreatic duct)
- Accessory pancreatic duct of Santorini
What is the peritoneal relation of the descending duodenum?
secondary retroperitoneal
What is the peritoneal relation of the inferior horizontal duodenum?
secondary peritoneal
What crosses the inferior horizontal duodenum?
The SMA/SMV and root of mesentery
What is the peritoneal relation of the ascending duodenum?
Secondarily retroperitoneal
What are the 3 branches that supply the duodenum?
- Superior pancreaticoduodenal (from gastroduodenal)
- Gastroduodenal artery (from common hepatic)
- Inferior pancreaticoduodenal (from SMA)
What is the first / minor Riolan anastomosis?
Anastomosis of inferior and superior pancreaticoduodenal arteries. It marks the border between foregut and midgut embryologically
What is the innervation of the duodenum (2)?
- Parasymp : vagus
- Syp : greater and lesser splanchnic nerves
What is the peritoneal relation of the descending duodenum?
secondary retroperitoneal
What is the peritoneal relation of the inferior horizontal duodenum?
secondary peritoneal
What crosses the inferior horizontal duodenum?
The SMA/SMV and root of mesentery
What is the peritoneal relation of the ascending duodenum?
Secondarily retroperitoneal
What are the 3 branches that supply the duodenum?
- Superior pancreaticoduodenal (from gastroduodenal)
- Gastroduodenal artery (from common hepatic)
- Inferior pancreaticoduodenal (from SMA)
What is the first / minor Riolan anastomosis?
Anastomosis of inferior and superior pancreaticoduodenal arteries. It marks the border between foregut and midgut embryologically
What is the innervation of the duodenum (2)?
- Parasymp : vagus
- Symp : greater and lesser splanchnic nerves
What is the peritoneal relation of the jejunum?
It’s intraperitoneal
What is the innervation of the jejunum and ileum?
Parasymp : vagal trunks
Symp : T8-T10 sympathetic trunk and lesser splanchnic nerves
What is important about the ileum histologically? (4)
- Peyer patches on the opposite side of the mesentary
- Short plica circularis
- More mesenteric fat than jejunum
- Short vasa racta
What is Meckel’s diverticulum?
A remnant of the yolk stalk of the embryo, persists abnormally, “close” to the the ileocecal junction
From where to where does the root of mesentery extend?
from the duodenojejunal flexure to the ileocecal junction
At what level does the SMA arise?
At the level of L1
What is the arterial supply of the jejunum an ileum?
SMA, which gives 15-18 jejunal and ileal branches that form the intestinal arterial arcades
What are haustra of the colon?
sacculations of the colon separated by haustral folds
What is the innervation of the jejunum and ileum?
Parasymp : vagal trunks
Symp : T8-T10 sympathetic trunk and lesser splanchnic nerves
What are the 3 features that differenciate small and large intestines?
- omental appendices (little fat pads)
- teniae coli
- haustra
What are teniae coli?
3 bands in which the longitudinal muscle fibers are gathered (not including rectum and anal canal)
What is the mesocolic teniae?
Where transverse and sigmoidal mesocolon attach
What is omental teniae?
Site of adhesion of the greater omentum to the transverse colon
What is teniae libera?
Teniae with no attachments
What are haustra of the colon?
sacculations of the colon separated by haustral folds
What is the peritoneal relation of the cecum?
It is semi-intraperitoneal
What is the ileocecal valve of Bauhin?
invaginations of the cecum caused by the ileum. The folds meet and form a valve
What is the vermiform appendix?
A blind intestinal diverticulum that contins masses of lymphoid tissue
What is the artery that supplies the cecum and the appendix?
The ileocolic artery
At which point is the vermiform appendix located?
At McBurney’s point
What is the peritoneal relation of the ascending colon?
Retroperitoneal (or semi-intraperitoneal)
What can we find between the ascending colon and the abdominal wall?
The right paracolic gutter, which is continuous with Subhepatic recess and Morrison’s pouch
What is Jackson’s membrane?
A membrane covering the anterior surface of the ascending colon that may cause obstruction
What is the arterial supply of the ascending colon? (3)
Ileocolic, right colic and middle colic branches of SMA
What is the arterial supply of the transverse colon? (2)
Middle colic branch of SMA and left colic branch of IMA
What is the 2nd/major arch of Rioland?
Anastomosis of the left colic artery with the middle colic artery
What is the peritoneal relation of the transverse colon?
intra-peritoneal
What is the peritoneal relation of the descending colon?
Retroperitoneal
What is the peritoneal relation of the sigmoid colon?
Intraperitoneal
What is the branch that supplies the descending colon?
The left colic artery
What is the marginal artery of Drummond?
Anastomosis of left and right colic arteries
How do we find the rectosigmoidal junction?
We see it thanks to the termination of teniae
What is the arterial supply of the sigmoid colon?
sigmoidal artery (from IMA)
What is Sudeck’s point?
Anastomosis of sigmoidal artery and superior rectal artery
What is the innervation of the colon?
- Parasymp : vagus nerves until 2/3 of transverse, then sacral plexus. It changes at Cannon Bauhm point
- Symp : superior hypogastric plexus
At which level do we find the rectosigmoidal junction?
At S3
What is the innervation of the rectum?
Parasymp : pelvic splanchnic nerves
Symp : lumbar part of sympathetic trunk and superior hypogastric plexus
What is Kohlrauasch’s fold?
The transverse rectal fold on the right side, that is most prominent
What is the ampulla of rectum?
dilated part of the rectum below Kohlrausch’s fold
What are the peritoneal relations of the rectum?
Superior 1/3 : intraperitoneal
Middle 1/3 : retroperitoneal
Inferior 1/3 : infraperitoneal
What are the 3 components of the external anal sphincter?
- subcutaneous
- superficial
- deep
What forms the anal cushions?
the superior rectal artery
What are the 2 ways of venous drainage for the rectum?
- Through the rectal veins
- Through the submucosal rectal plexus
What is the innervation of the rectum?
Parasymp : pelvic splanchnic nerves
Symp : lumbar part of sympathetic trunk and superior hypogastric plexus
Where does the anal canal begin?
At the level of the puborectalis forming a U shaped swing
Which anal sphincter is voluntary and which is involuntary?
Internal anal sphincter : involuntary
External anal sphincter : voluntary
What is the internal anal sphincter a thickening of?
Thickening of the circular smooth muscle layer
What are the 3 components of the external anal sphincter?
- subcutaneous
- superficial
- deep
What is zona cutanea?
zone that continues below the anocutaneous line, lined by stratified squamous keratinized non-hairy epithelium
What do the anal columns of moragni contain?
they contain the superior rectal artery and vein
What happens to the mucosa in the inferior part of the anal canal?
It forms the anal valves of Morgagni
What can we find between the anal columns and the anal valves?
The anal sinuses
What is the pectinate line?
It indicates the junction of the superior and inferior part of the anal canals, each derived from the hindgut and the proctodeum respectively
What is zona columnaris?
zone from anorectal junction to pectinate line, covered by simple columnar epithelium
What is zona hemorrhagica?
From the pectinate line until the Hilton white or anocutaneous line, covered by stratified squamous non K epithelium
What is zona cutanea?
zone that continues below the anocutaneous line, lined by stratified squamous keratinized non-hairy epithelium
Where is the Hilton white line / intersphincteric groove?
At the level of the itnerval between the subcutaneous part of the external anal sphincter and the lower border of the internal sphincter
What do we call the “anoderm”?
The zona hemorrhagica and cutanea together
What is the innervation of the anal canal?
Superior to pectineate line : inferior hypogastric plexus
Inferior to pectineate line : inferior anal / rectal nerves
