23. The Digestive System

Where are bile salts reabsorbed in the small intestine?

Lactose, a sugar found in milk, can only be digested by lactase, a brush border enzyme. All babies produce lactase, but only some adults do. Adults who do not produce lactase are referred to as lactose intolerant, as the presence of undigestible lactose can lead to uncomfortable digestive side effects such as gas and diarrhea. Based on your understanding of the small intestine, where would you expect to find the most lactase in babies and those adults that can digest lactose?

How does absorption of lipids differ from absorption of carbohydrates and proteins in the small intestine?

a. Lipids are absorbed into a capillary; carbohydrates and proteins are absorbed into a lacteal.

b. Lipids are not absorbed in the small intestine.

c. Lipids are absorbed into a lacteal; carbohydrates and proteins are absorbed into a capillary.

d. They are all absorbed into the same structure.

Celiac disease is a condition where the body has an abnormal immune response to the protein gluten found in wheat and other grains. A result of this, the body’s immune response can cause damage to the villi. Based on your knowledge of the small intestine, what function would this this most directly affect?

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. During eating, the small intestine exhibits motion in the migrating motor complex pattern.

A lacteal can be found within each:

Which of the following statements is true?

The most numerous type of epithelial cells in the small intestine are the

What are the three folds of the small intestine called? What is their purpose?

Both Paneth cells and Peyer’s patches are more numerous in the ileum than in the jejunum or the duodenum. Which statement below correctly describes why that may be?

Which of the following is/are absorbed in the small intestine by the Na+/glucose cotransporter?

a. Glucose

b. Galactose

c. Fructose

d. Both a and b are correct.

e. All of the above are correct.

Gastric bypass surgery involves creating an alternate pathway for food that bypasses the majority of the stomach and a portion of the small intestine to help patients lose weight. A schematic is shown below.

Why do you think it is important to attach the duodenum to the jejunum even if food is no longer passing through it?

Which of the following statements are true about motility in the small intestine:

I. Peristalsis will generally propel chyme towards the ileocecal valve.

II. The efficiency of chemical digestion can be increased through segmentation.

III. Peristalsis and segmentation use the same muscles, but contract in different patterns.

As a treatment for certain diagnoses, a section of the small intestine may be removed from a patient. Based on your understanding of their respective functions, a portion of which section of intestine do you think could be removed with the fewest adverse side effects and why?

Which pathway correctly identifies the path of chyme as it moves through the small intestine?

Two chyme samples are taken: one from the stomach and one from the duodenum. How could you tell the samples apart using lab techniques?

The brush border enzymes are associated with which level of the small intestine?