lecture 22 Flashcards
three regions of the small intestine?
duodenum
jejunum
ileum
total length of the small intestine?
~6m
longest region of the small intestine?
ileum
which segment of the duodenum if retroperitoneal?
the initial segment
what holds the small intestine in place?
mesentery
what is contained in the small intestine mesentery?
arteries
veins
nerves
lymphatics
what is the main function of small intestine?
absorption
how is the small intestine modified for its function?
plicae circulares
what are plicae circularis?
permanent large folds of the small intestine, core of submucosa
what is found on the surface of the plicae circulares?
villi
what allows villi to move back and forth?
muscularis mucosae
what is the core of each villi made of?
FCT, lamina propria
what is in the core of the villi?
lymph lacteal
capillary Network
what enters the mesenteric veins?
nutrient rich, deoxygenated blood absorbed in the small intestine
where do mesenteric veins drain?
hepatic portal vein
how does the small intestine increase its surface area?
long 6m length
permanent folds (plicae circularis)
villi
microvilli
What is the epithelium of the small intestine?
simple columnar
where is the microvilli?
on the apical surface of simple columnar epithelium
What is contact digestion?
involves brush border enzymes
what diffuses through tight junctions?
small molecules
what are enterocytes?
absorptive cells
