Small Intestine Flashcards
How long is the duodenum?
20-25 cm long
Where is the duodenum located?
first to third lumbar region
What are the sections of the duodenum?
Superior- 5cm long passing from pyloric sphincter to the gallbladder
Descending- location of major and minor duodenal papillae (7.5cm long)
Inferior- 10 cm long
Ascending- connects to jejunum at duodenal jejunal flexure
Explain the histology of the duodenum
Plicae Circularis are folds in the mucosa and submucosa which allow for a greater surface area.
the mucosa is lined with simple columnar epithelium (same as stomach) and the villi and microvilli help too.
Crypts of Lieberkuhns are deep glands which allow secretions of mucus from Brunner’s glands which are only found in the duodenum
describe the five regions of the pancreas
tail heading from the left kidney, body, neck, head and uncinate process.
What is the function of the pancreas?
the pancreas has an exocrine and endocrine function.
the exocrine function comes from the secretory acinus’ which produce enzymes like chymotrypsin, bicarbonates and lipases. these travels to the duodenum through the hepatopancreatic ampulla into the major duodenal papilla
the endocrine function comes from the Islet’s of Langerhans
Alpha- glucAgon
Beta- insulin
delta- somaTostatin
What drains the pancreas?
the pancreas is drained by the main pancreatic duct which joins the common bile duct to form the hepatopancreatic ampulla
the head and uncinate process of the pancreas is drained by the accessory ducts, which flow into the minor duodenal papilla
what is the spleen composed of?
lymphoid tissue. it is essential in filtering blood
describe the spleen
covered in visceral peritoneum except for the hilum.
attached to greater curvature and left kidney by greater omentum.
attached by gastrosplenic ligament to stomach and renal splenic ligament to the kidney
what is the histology of the spleen?
the spleen is made of dense connective tissue. it has red and white pulp.
Describe the blood supply to the duodenum
the duodenum is supplied by the gastroduodenal artery and superior mesenteric artery which comes off the common hepatic artery.
describe blood supply to the pancreas
the pancreas is supplied by the splenic artery on the superior border of the pancreas.
blood supply to the spleen
splenic artery
describe the portal venous system
portal venous system is the drainage of blood from the GI tract to the liver for detoxification. the splenic vein drains the stomach, the superior mesenteric drains the duodenum and ascending colon, and the inferior mesenteric drains the rest of the colon
