Download 164 study guide digestion

Biology 164 – Study Guide
Digestive System
Chapter 15
Terms
Be familiar with the definition and physiological/anatomical significance of:
bile, brush border, brush border enzymes, chyme, chief cells, cholesterol, defecation
reflex, emulsification, gallbladder, gastric juice, haustra, heterocrine gland, lipases,
microvilli, mucosa, muscularis externa, pancreatic amylase, parietal cells,
pepsinogen/pepsin, peristalsis, plica circulares (intestinal folds), salivary α-amylase,
salivary glands (parotid, submandibular, sublingual), serosa, submucosa, submucosal
plexus, villus (villi)
To what extent do plica circulares (intestinal folds), villi, microvilli each increase the
internal surface area of the small intestinal? How much greater is the internal surface
area of the small intestine than it would be without all of these modifications? Why is
this important?
What are five general functions of the digestive system?
Know the general plan for the layers of digestive tract. I.e. mucosa, submucosa,
muscularis externa, serosa/adventitia.
What is found in each of these layers? E.g. mucosa = epithelium, lamina propria,
muscularis mucosae.
Know the major function(s) of each organ of the digestive system that we discussed in
class?
Focus on how the structure of the layers of a particular portion of the digestive tract is
related to its specific function.
E.g. The stomach has three (3), not two (2), layers of smooth muscle in its
muscularis externa → a major function of the stomach is mechanical digestion.
E.g. Brunner’s glands in the duodenum protect it from acidic chyme from the
stomach.
What is the individual functions of the amylase, buffers and mucus found in saliva?
What cell types are found in the mucosa of the stomach? Functions of these?
Be familiar with the many general functions of the liver.
Be familiar with Table 15.1, Review of Structures of the Gastrointestinal Tract and Table
15.3, Review of Accessory Structures of the Digestive System.
Why is bicarbonate present in pancreatic juice?
What is meant by the term “intestinal brush border”? How is the brush border important
to digestion?
What role do bile salts play in lipid digestion?
Which organ is responsible for most of the digestion that occurs in the digestive tract?
Which organ reabsorbs the most water?
Practice questions
1. The layer of the gastrointestinal tract that is actually in contact with ingested food is
the ___.
a. adventitia
b. mucosa
c. muscularis externa
d. serosa
e. submucosa
2. One of the salivary glands releases a watery fluid containing salivary amylase and
almost no mucus into ducts that open into the mouth near the upper second molar. This
is the ___ salivary gland.
a. parotid
b. sublingual
c. submandibular
d. submaxillary
3. Parietal cells secrete ___.
a. alkaline (basic) mucus
d. hydrochloric acid
4.
a.
b.
c.
d.
e.
b. alpha-amylase
e. pepsinogen
c. gastric lipase
Which of the following is NOT a function of the liver?
activates Vitamin D
detoxifies drugs
interconverts organic molecules
phagocytizes worn-out red blood cells
secretes pepsin
5. The modification of the wall of the small intestine that increases its internal surface
area to the greatest degree is the:
a. cilia
b. intestinal glands
c. microvilli
d. plica circulares (intestinal folds)
e. villi
6.
a.
b.
c.
d.
e.
Which order is anatomically correct?
stomach → duodenum → ileum → jejunum cecum
stomach → duodenum → jejunum → ileum → cecum
stomach → ileum → duodenum → jejunum → cecum
stomach → ileum → jejunum → duodenum → cecum
stomach → jejunum → duodenum → ileum → cecum
7.
a.
b.
c.
d.
e.
Which of the following is NOT true of the large intestine?
it absorbs water
it absorbs vitamins produced by bacteria
its glands secrete digestive enzymes
its goblet cells produce protective mucus
its submucosa contains aggregations of white blood cells
8. Bile salts are enzymes that digest fats into fatty acids and monoglycerides.
a. true
b. false
9. The pancreas secretes bicarbonate ions into the ___ in order to ___ the pH of the
chyme.
a. duodenum; lower
b. duodenum; raise
c. stomach; lower
d. stomach; raise
10. Bile is stored and is concentrated in the ___:
a. gallbladder
b. liver
c. pancreas
1
2
3
4
B
A
D
E
5
6
7
8
C
B
C
B
9 B
10 A
d. small intestine
e. spleen