Video Transcript
The diagram shows a single villus,
with the lacteal indicated. What is the function of the
lacteals in the small intestine? (A) To break down carbohydrates and
proteins into their monomers. (B) To absorb fats and fat-soluble
substances into the lymphatic system. (C) To emulsify fats. (D) To store and release digestive
enzymes. (E) To absorb useful nutrients into
the bloodstream.
The small intestine is a digestive
organ specialized in digesting food and absorbing nutrients. Let’s examine how the small
intestine works in more detail. It’s coated in multiple tiny bumps
called villi to increase its surface area. We can see a single villus
magnified here. Each villus is made up of
epithelial cells called enterocytes. These are covered with tiny
projections called microvilli that increase the surface area of the small intestine
even further to absorb nutrients.
Nutrients diffuse into the
enterocytes and can enter either the capillaries or the lacteals. The capillaries take up
water-soluble nutrients, which can then enter the bloodstream. And the lacteals take up
fat-soluble nutrients, such as vitamins A, D, E, and K. These nutrients can then enter the
lymphatic system before they eventually end up in the bloodstream later in the
process.
Therefore, the function of the
lacteals in the small intestine is given by answer choice (B), to absorb fats and
fat-soluble substances into the lymphatic system.
