Video Transcript
The liver is a very important
metabolic organ, so it receives the products of digestion directly from the small
intestine where they are absorbed. Which blood vessel connects the
liver and the small intestine? (A) The hepatic portal vein, (B)
the renal artery, (C) the pulmonary vein, (D) the inferior vena cava.
Here is a diagram showing an
overview of the digestive system. Food travels through the mouth,
goes through the esophagus, into the stomach, through the small intestine, through
the large intestine, and finally out the anus. You may notice that there are some
digestive organs that food doesn’t travel through. These are called accessory organs,
and the liver is one example.
The liver secretes bile, which
helps digest lipids. Another organ that relates to this
question is the small intestine, which digests food and absorbs nutrients. Let’s look more closely at how this
process occurs in the small intestine.
The small intestine is coated in
tiny fingerlike projections called villi that increase the surface area. We can see one of them magnified
here. They are made up of multiple
epithelial cells called enterocytes that have tiny projections called microvilli to
increase the surface area of the small intestine even further.
Nutrients diffuse into the
enterocytes. And once inside, water-soluble
nutrients diffuse into the capillaries and fat-soluble nutrients diffuse into the
lacteal, which are the lymphatic vessels of the small intestine. Now that we understand how
nutrients enter the bloodstream, let’s look at how the small intestine and liver are
connected.
As we can see here, blood travels
from the small intestine to the liver through the hepatic portal vein before going
to the heart by the inferior vena cava. Therefore, the blood vessel that
connects the liver and small intestine is given by answer choice (A), the hepatic
portal vein.
