23. The Digestive System

A surgical procedure known as gastric bypass involves removing all or part of the stomach.

How would stomach removal affect absorption of vitamin B12? Explain.

Troy Francis, a middle-aged salesman, complains of a burning pain in the 'pit of his stomach,' usually beginning about two hours after eating and abating after drinking a glass of milk. When asked to indicate the site, he points to his epigastric region. The GI tract is examined by X-ray fluoroscopy. A gastric ulcer is visualized, and drug therapy using a proton pump inhibitor and antibiotics is recommended.

a. Why is this treatment suggested?

b. What are the possible consequences of nontreatment?

The sphincter between the stomach and duodenum is:

a. The pyloric sphincter

b. The gastroesophageal sphincter

c. The hepatopancreatic sphincter

d. The ileocecal valve

Which area/structure is NOT a component of the pyloric part of the stomach?

Which layer of the muscularis externa only exists in the stomach?

Match the letter of the digestive organ shown in the figure with its function.

___ churning occurs here

Nutritionists have found that after a heavy meal, the pH of blood increases slightly, especially in the veins that carry blood away from the stomach. What causes this increase in blood pH?

The lamina propria forms part of the:

a. Muscularis externa

b. Submucosa

c. Serosa

d. Mucosa

Which of the following statements about chemical digestion in the stomach are correct:

I. Lipid digestion is begun by enzymes known as lipases.

II. HCl is breaks starches into component monosaccharides. 

III. Proteins are denatured by the protein pepsin.

Match the following terms with the correct definition. 

__Chief cells          

__Parietal cells           

__Gastrin           

__Pyloric sphincter         

__Diffuse neuroendocrine (DNES) cells         

__Gastroesophageal sphincter         

__Pepsin         

__Chyme

a. Hormone that stimulates multiple digestive processes

b. Enzyme that begins protein digestion

c. Produce acid and intrinsic factor

d. Liquid produced as a result of stomach churning

e. Produce pepsinogen

f. Cells in gastric glands that produce hormones

g. Controls passage of bolus from esophagus to stomach

h. Controls passage of stomach contents to duodenum

Which of the following occurs/occur during the cephalic phase of gastric acid secretion?

a. Stimulation of gastrin and histamine release

b. Direct stimulation of parietal cells

c. Inhibition of somatostatin release

d. Both a and b are correct

e. All of the above are correct