The Foregut Flashcards
Where does the foregut run from and to?
Phraynx to proximal duodenum
Where does midgut run?
From distal duodenum to the proximal half of trnavserse colon
Where does the hindgut run?
From the distal third of transverse colon to the rectum
What does the small intestine include?
Duodenum
Jejunum
Ileum
What does the large intestine include?
Caecum
Appendix
Colon
What is the oesophagus?
Muscular tube
25cm long
Pharynx to stomach
What are the 3 constrictions of the oesophagus?
Cervical
Thoracic
Diaphragmatic
In which mediastinum is the oesophagus located
Posterior and superior
What is the vertebral level of the oesophageal opening (hiatus) in the diaphragm?
T10
What are the other structures which pass through the diaphragm at the oesophageal opening?
Oesophagus
Vagus nerve
Oesophagel branches of the left gastruc artery and vein
Lymphatics
What is oesophageal varices?
The lower end of the oesophagus is one of the important sites for portosystemic anastomoses.
In portal hypertension, the anastomoses open and forms venous dilatations called oesophageal varices.
Their rupture causes severe and dangerous haematemesis
What is the blood supply of the oesophagus?
Left gastric artery and left inferior phrenic artery
What is the venous drainage of the oesophagus?
Portal and systemic systems
Left gastric vein- Porta
Oesophageal veins- Azygous vein so systemic
Systemic- Portal anastosmosis
What is the lymohatic drainage of the oesophagus?
Left gastric lymph node to celiac nodes
What is the stomach?
A muscular bag forming the widest and most distendible part of the digestive tube
Where does the lesser omentum extend from?
Lesser curvature to liver
Where does the greater omentum extend from?
Greater curvature to beginning of duodenum
What is the pyloric sphincter?
Band of smooth muscle at the junction between the pylorus of the stomach and the duodenum of the small intestine
What is the function of the pyloric sphincter?
Digestion where it acts as a valve to controls the flow of partially digested food from the stomach to small intestine
The pyloric sphincter is formed from the thickening of which layer of gut tube?
Inner circular layer
What is pyloric stenosis?
Some children are born with a condition called congenital pyloric stenosis.
This is a narrowing of the opening from the stomach to the first part of the small intestine (the pylorus).
Symptoms include projectile vomiting without the presence of bile.
What are the gastric folds formed from?
Tissue- mucosal and submucosal
They are most apparent in the pylroic part and greater curvature
What are the 3 branches of the coeliac trunk?
Left gastric artery
Splenic artery
Common hepatic artery
What is venous drainage of the stomach done by?
The portal system
What are the 4 main veins draining the stomach?
- Left gastric vein which drains into the hepatic portal vein.
- Right gastric vein which drains into the hepatic portal vein.
- Left gastro-omental which drains first to the splenic vein then to the hepatic portal vein.
- Right gastro-omental which drains first to the superior mesenteric vein then to the hepatic portal vein.
What group of nodes do the central group ofnodes drain to?
Pre aortic nodes at T12
What is the parasympathetic nerve supply of the stomach come from?
Vagus nerve
What does the sympathetic supply of the stomach come from?
great splanchnic nerve (t6-t9) pass through the celiac plexus
What is the effect of increased vagal stimulation on the stomach?
The pylorus?
Gastric secretion?
Increasing pyloric opening
Promotes gastric empyting
What does the arrangement of the vagal branches to the stomach allow?
For highly selective vagotomy to be used to treat over- active gastric acid secretion.
This denervates the fundus and body, decreasing secretion, while the supply to the antrum remains so preserving essential gastric motility.
What is the duodenum?
C shaoed structure which continues from the pyloric sphincter of the stomach
The duodenum is the first part of the small intestine
How many parts does the duodenum have?
Superior
Descending
Inferiror
Descending
What organ sits within the C shape of the duodenum?
Pancreas
How is the duodenum peritonised?
Retroperiotnal
There is a small opening in the duodenum where pancreatic and bile fluids enter the gut tube. What is this opening called?
Major duodenal papilla which is the eminence that the hepatopancreatic ampulla opens into
- What two structures come together at the major duodenal papilla?
Main pancreatic duct
Common bile duct
What is the sphincter that controls the opening called?
Sphincter of oddie
