Small Intestines Flashcards
what is the small intestine comprised of?
duodenum, jejunum, ileum
what is the function of the small intestine
primary site for digestion and absorption
in relation to the peritoneum where does the small intestine lie?
partially retroperitoneal
what does mesentery mean?
double folds of the peritoneum
what is the omentum
a fatty layer which localises infections as it makes sure it is held in place and contained
what does the duodenum receive?
chyme
what do Brunner’s glands secrete
alkaline
what part of the small intestine contains Brunners glands?
duodenum
what is the sphincter of Oddi and what part of the small intestine does it join to?
the common bile duct and it joins to the duodenum
what does the sphincter of Oddi secrete?
bile and pancreatic juice
where does the duodenum end?
the duodenojejunal junction
what is chyme?
fluid that comes from the stomach into the small intestine
what does alkaline secretion do?
neutralise hydrochloric acid
where does bile come from and where is it stored
comes from the liver and is stored in the gall bladder
in relation to the vertebrae where does the duodenum lie?
L1-L4
what does the major duodenal papilla secrete?
secretions from bile and pancreatic juices
what is the major duodenal papilla?
the opening of the pancreas into the duodenum
what does cholecystokinin do?
causes contraction of the gall bladder with high fat diets which allows bile to be produced (bile sack mover)
what are the 4 parts of the duodenum?
superior, descending, inferior and ascending
what does the inferior vena cava do?
drains all the blood from below the heart
what does the superior mesenteric artery do?
supplies the mid gut with blood and comes straight from the aorta
what does the coeliac trunk lead to?
the superior pancreaticoduodenal artery
what does the superior mesenteric artery lead to?
the inferior pancreaticoduodenal artery
how many blood supplies does the duodenum have?
2 - one at the top and one at the bottom
what is the main function of the duodenum and what helps it complete its function?
digestion, pancreatic enzymes and bile
what is the main function of the jejunum?
digestion and absorption
what is the main function of the ileum
absorption
what are the layers of the jejunum and ileum?
lumen, mucosa, submucosa, muscularis externa and adventitia
what are the layers of the mucosa in the jejunum and ileum?
epithelium, lamina propria, muscularis mucosae
what are the layers of the muscularis externa?
innermost oblique (stomach only), inner circular, outer longitudinal
what do the submucous plexus and myenteric plexus do?
cause contraction
what do plicae circulares do?
increase surface area in small intestine by about 1.6-2x
what do the villi and microvilli do?
increase surface area by 60-200x
where are the microvilli?
on top of the villi
why does the intestine become more windy towards the bottom?
it increases absorption
what is peyers patch?
collection of inflammatory tissues
what enterocyte helps with digestion?
brush border enzymes
what enterocyte helps with absorption?
carrier proteins
what is the ileocaecal junction?
where the ileum joins to the caecum and where the small intestine connects to the large intestine
