Class 3 Flashcards
Where is the oesophagus constricted?
- Cervical
- Thoracic
- Diaphragmatic (Oesophageal hiatus at T10)
What structures go through the oesophageal hiatus?
- Oesophagus
- Vagus nerve
- Left inf. phrenic vessels
- Small oesophageal arteries (branches of the left gastric artery)
Explain the arteries, veins and lymphatics of the abdominal oesophagus?
Art = Branches of Left Gastric Artery Veins = Left Gastric vein -> Portal Vein Lymphatics = follows Left gastric artery to gastric & coeliac nodes
What happens around the lower end of the oesophagus when theres portal hypertension?
The portosystemic anastomoses become dilated, their rupture can cause severe & dangerous haematemesis.
These are called oesophageal varices
What are the orifices, curvatures & surfaces of the stomach?
- Cardiac orifice (+ sphincter) & Pyloric orifice (+ sphincter)
- Greater & Lesser curvature
- Anterior & Posterior surfaces
Define the pyloric sphincter?
Band of smooth muscle between stomach pylorus & Duodenum.
It functions by controlling gastric outflow
Formed from the thickening of the circular (inner) layer of muscularis externa
Describe the greater/lesser omenta?
Greater omentum - Greater curvature of the stomach to transverse colon
Lesser Omentum - Lesser curvature of the stomach to the liver
Where does the epiploic foramen pass?
Behind the lesser omentum over the stomach from greater to lesser sac.
What layers of the stomach from the gastric rugae?
Mucosa submucosa
(Mi casa et tu casa)
They are most apparent in the pylorus and body of the stomach
What forms the stomach bed?
The structures on which the stomach lies:
- Pancreas
- Left Kidney
- Spleen
- Left Suprarenal gland
- Transverse and mesocolon
- Splenic artery
- Left dome of diaphragm
Explain the arterial supply of the stomach? Probably easier just to look at the diagram in the workbook
Coeliac Trunk splits into common hepatic artery, left gastric artery and splenic artery.
- The left gastric artery supplies the top and gastroesophageal junction
The common hepatic then splits into the right gastric, true hepatic and gastroduodenal arteries.
- The right gastric supplies the lesser curvature
- The gastroduodenal artery gives off the right gastroepiploic artery which supplies the distal section of the greater curvature
The splenic artery gives off the short gastric arteries suppling the fundus and the Left Gastroepiploic artery which supplies the proximal half of the greater curvature
Explain the arterial supply of the colon:
Abdominal aorta gives off the superior (L1/L2) and inferior mesenteric (L3) arteries.
Superior mesenteric:
- Ileocolic = supplies caecum and ileocaecal junction
- Right Colic = Often absent but otherwise Supplies Asc. colon
- Middle Colic = Supplies hepatic flexure and proximal transverse colon and Asc. Colon if right absent.
Inferior Mesenteric:
- Left colic = supplies Desc. Colon
- Sigmoid = Sigmoid Colon
- Superior Rectal = Main supply of rectum
(Also the internal iliac branches to form inferior/middle rectal arteries, the middle is often absent)
All the branches of the Sup & Inf Mesenterics described above are connected round the border of the colon by the marginal artery
Explain the lymphatics of the colon?
Follows the arterial supply and has to be removed when removing a cancer.
- Epicolic (on wall of colon)
- Paracolic (Next to colon)
- Intermidiate (Along main arteries of colon)
- Central or principle (Along large vessels e.g. sup. mesenteric)
Drains to the superior and inferior mesenteric lymph nodes based on location
Explain the veins of the colon?
Same as the arteries except:
Inferior mesenteric feeds into splenic.
Then splenic and superior mesenteric combine to form the portal vein going into liver.
Explain the lymphatic drainage of the stomach?
Split into four groups:
Pyloric - Around pylorus
Superior Gastric - Around upper end of lesser curvature and gastroesophageal junction
Pancreaticosplenic - Along splenic artery and posterior of stomach
Inferior Gastric - on greater curvature
All drain into the ceoliac nodes
{Gastric carcinoma most often occurs along the greater curvature}
How does vagal stimulation affect the pylorus and gastric secretion?
Vagal stimulation causes pylorus to relax and gastric secretion to increase
Describe “highly selective vagotomy of the stomach”
Cutting specific vagal branches to the fundus and body decreases gastric secretion to treat overactive gastric acid secretion
While the antrum remains unaffected so gastric motility is preserved.