GI Anatomy Flashcards
At what level does the gastro-oesophageal junction lie?
T10
Which part of the stomach is most superior and can become dilated with gas?
Fundus
The angular incisure marks the boundary between which two parts of the stomach?
Stomach body and the pyloric antrum
The stomach is an intraperitoneal organ. T/F?
True
What is the name of the folds of the stomach which flatten out to allow it to expand in volume?
Rugae
The left and right gastric arteries supply the stomach via anastamoses at the lesser curvature. What is the origin of these arteries?
The left gastric artery is a direct branch of the coeliac trunk
The right gastric artery comes from the common hepatic artery which also originates from the coeliac trunk
The anastomoses of the left and right gastro-epiploic arteries supply the stomach at the greater curvature. What is the origin of these arteries?
The left gastroepiploic artery comes from the splenic artery
The right gastroepiploic artery comes from the gastroduodenal artery
Lymph from the stomach drains into which nodes?
Coeliac nodes
What is the innervation of the stomach?
Parasympathetic innervation is 5rough the vagus nerve
Sympathetic innervation is through the splanchnic nerves (T6-T9)
Where does the duodenum lie in relation to the peritoneum?
The duodenum is retroperitoneal apart from the first 2.5cm which are intraperitoneal
Describe the blood supply to the duodenum
The first part of the duodenum until approximately the major duodenal papilla is supplied by the superior pancreticoduodenal artery which is a branch if the gastroduodenal artery
The remainder of the duodenum is supplied by the inferior pancreaticoduodenal artery which is a branch of the superior mesenteric artery
To which nodes does lymph from the duodenum drain?
Coeliac and superior mesenteric nodes
Describe the innervation of the duodenum
Sympathetic - greater and lesser splanchnic nerves
Parasympathetic - vagus nerve
What type of epithelium exists in the stomach?
Simple columnar epithelium
Describe the four layered microstructure of the GI tract.
Muscosa - epithelium, lamina propria, muscularis mucosae
Submucosa - larger blood and lymph vessels
Muscularis externa - innermost oblique muscle (only in stomach), inner circular muscle, outer longitudinal muscle
Serosa
The myenteric and submucosal plexuses combine to form the enteruc nervous system. Where do these plexuses lie?
The submucosal plexus lies within the submucosa
The myenteric plexus lies between the inner circular and outer longitudinal muscle layers in the muscularis externa
What type of epithelium exists in the oesophagus?
Stratified squamous epithelium
What is the name of the glands within the duodenum which secrete bicarbonate ions to neutralise acidic gastric secretions?
Brunner’s glands
Peyers patches exist in the small kntestine - what do these do?
They are lymphatic areas which protect against ingested pathogens
The lower oesophageal sphincter is merely a physiological sphincter, not an anatomical sphincter. What does these mean?
There is no thickening of the muscle but the sphincter still functions to close the opening between the oesophagus and cardia of the stomach
What is the greater omentum?
A large apron like fold of peritoneum which hangs from the greater curvature of the stomach and is mainly comprised of fatty tissue
What is the lesser omentum?
A small fold of peritoneum which exists between the liver and the stomach
The lesser sac allows the motility and expansion of the stomach. T/F?
True
What is the name of the foramen in the lesser omentum which provides a communication between the greater and lesser sac?
Epiploic foramen
What is the infracolic compartment?
The region of the greater sac which exists inferior to the transverse colon
What is the subphrenic space?
A potential space which sits between the right lobe of the liver and the inferior surface of the diaphragm
Which ligament divides the subphrenic space into a right and left half?
Falciform ligament
What is the name of the embryological remnant of the umbilical vein?
Ligamentum teres or round ligament of the liver
In terms of surface anatomy, where does the fundus of the gallbladder lie?
Where the latera edge of the recus abdominus (linea semilunaris) meets the costal margin
What features of the small intestine enhance its absorptive function?
The surface area of the small intestine is very large to help with absorption. This is achieved by:
Long length of intestine
Plicae circularis (permanent folds of the mucosa and submucosa)
Villi
Microvilli
What cells are contained in the crypts which exist between villi in the small intestine?
Enteroemdocrine cells
Paneth cells
Stem cells