Absorption in the small intestine Flashcards
Describe how the small intestine is adapted for absorbing the products of digestion
what do all these features mean?
has VILLIS(increase surface area for absorption of molecules)
villis have MICROVILLIS(large surface area is created)
villis have a GOOD BLOOD SUPPLY so bloodstream can quickly remove products of digestion
the villi have a THIN MEMBRANE that ensures a short diffusion path
all of these features mean that there is a rapid rate of diffusion
any molecule that can’t be absorbed by diffusion are absorbed by active transport
where are the products of digestion absorbed ?
into the bloodstream of the SMALL INTESTINE
how long is the human small intestine and what does this mean?
around 5m
provides a very large surface area for absorption of the products of digestion
what is the interior/inside of the small intestine covered with?
what do these do?
millions of villi
villi massively increase the surface area for the absorption of molecules
what can we find on the surface of villi?
what do these do?
microvilli
microvilli also increase the surface even further
what property do villis have that is beneficial?
villi have a very good bloody supply so the bloodstream rapidly removes the products of digestion
in the small intestine, what factor increases the concentration gradient?
Villi having a very good blood supply so the bloodstream quickly removes the products of digestion means the concentration gradient is increased.
what in the villi ensures a short diffusion path?
the thin membrane
what does the thin membrane in the villi ensure?
a short diffusion path
these adaptations all mean that…
there is a rapid rate of diffusion of the products of digestion into the bloodstream
any molecules that can’t be absorbed by diffusion or absorbed by what?
active transport
