Hello! In this
we’re going to go through a
number of very important topics.
We’re going to talk specifically
about both absorption and digestion.
Here, we're going to specifically focus
on understanding how carbohydrates,
fats, proteins are digested
and identify the enzymes
that are primary involved
in these processes.
We will also talk about the absorption
of basic macronutrients, ions, and water
as well as other electrolytes
as they enter places
like the portal vein or the
Finally, we’re going to focus on the various
portions of the splanchnic circulation
that will help deliver this food
stuff to the rest of the body
and therefore provide the energy needed
in undergoing normal daily activities.
So digestion, absorption,
these are what our main topics
will be for today’s lecture.
Just to give you an overall
kind of review of what
specific items are going
to be most important.
Today, we’re going to discuss
absorption and digestion.
This is primarily going to occur in places
like the reaction vessel in the stomach,
the catalytic and absorptive
surface in the small intestine.
But we’re going to need some
supply of enzymes from places like
the enzyme supplier
from the pancreas.
So digestion in a simplistic format
is simply going to be taking a
molecule from the intestinal lumen
and moving it across
the epithelial cells
into the interstitial space so it
can be picked up by the blood.
Using a classic example of glucose,
glucose can simply travel through these
enterocytes to be able to be absorbed.
Things that are a little bit
more complex such as proteins,
might need to broken down
into individual amino acids
or very short peptides to
be able to be transported.
Complex carbohydrates or even simple
carbohydrates such as sucrose
still need to be broken down to their
individual monosaccharides for absorption.
As you can see in this particular example,
you might need to break down a
peptide even to a greater extent
within the enterocyte so that you can
reabsorb the individual amino acid.
And finally, when we think of fats, which
is going to be some of our most complex
types of digestion
Here, you need to break down triglycerides
into individual fatty acids to absorb them.
But then it’s kind of odd,
you have to repackage them
for their transport out of the cell,
but to get them across
the intestinal lumen,
you’ll need to have
broken them down.
With that overview in mind,
let’s specifically talk through
the digestion of carbohydrates.