Essentials of Anatomy and Physiology

1. Many people with GERD take proton-pump
   inhibitors, medications that reduce stomach acid.
   Why should these people be especially careful
   about what they eat or drink?


2. The colon does not have villi as part of its mucosa.
   Explain why villi are not necessary.


3. Food remains in the stomach for several hours.
   Passage of food through the small intestine also
   requires several hours. These two organs have very
   different shapes. Explain why they are able to
   retain food for so long, for efficient digestion and
   absorption.


4. Diarrhea can be unpleasant, but does have a

purpose. Explain, and state the disadvantages as

well.

5. Explain how a spinal cord transection at the level of
   T10 will affect the defecation reflex.


6. You have seen the word enteric(or entero) several
   times in this chapter. What does it mean? Define
   each of these: enteric bacilli, enterovirus, Entero-
   coccus.


7. The word symbiosisindicates two different kinds of
   living things, and literally means “together-life.”
   Our own alimentary tube is a perfect example.
   Explain, and state the advantages to each living
   thing.

The Digestive System 393

FOR FURTHER THOUGHT

10. Describe the internal structure of a villus, and
    explain how its structure is related to absorption.
    (p. 384)


11. Name the parts of the large intestine, and
    describe the function of the ileocecal valve.
    (p. 385)


12. Describe the functions of the colon and of the
    normal flora of the colon. (pp. 385–386)


13. With respect to the defecation reflex, explain the
    stimulus, the part of the CNS directly involved,
    the effector muscle, the function of the internal

anal sphincter, and the voluntary control possible.

(p. 386)

14. Name the vitamins and minerals stored in the
    liver. Name the fixed macrophages of the liver,
    and explain their function. (p. 388)


15. Describe how the liver regulates blood glucose
    level. Explain the purpose of the processes of
    deamination and transamination. (pp. 386, 388)


16. Name the plasma proteins produced by the liver,
    and state the function of each. (p. 388)


17. Name the substances excreted by the liver into
    bile. (p. 388)