You and your friend are having dinner and you tell a funny joke. Your friend laughs at the same time he tries to swallow some water, and the water comes out his nose. Why has this happened?

General anesthesia eliminates the swallowing reflex but does not eliminate the feedback loops that cause vomiting. Considering this, explain why patients are advised not to eat or drink anything for at least 12 hours prior to undergoing surgery.

Drugs with anticholinergic side effects block ACh receptors in the peripheral nervous system, including those on digestive organs. Predict the effects such drugs would have on motility and secretion on the specific organs of the digestive system.

Mr. Williams presents to your clinic with a complaint of abdominal pain in the right upper quadrant. He says that the pain worsens when he eats, particularly when he eats fatty meals. He has noticed that his stool has been an unusual clay color recently. You perform an ultrasound of his abdomen and find that gallstones are blocking his common bile duct, preventing bile from entering the duodenum.

Why are his symptoms worse when he consumes a high-fat meal? Would you expect his symptoms to worsen or lessen when he consumes a meal consisting only of carbohydrates? Explain.

Mr. Williams presents to your clinic with a complaint of abdominal pain in the right upper quadrant. He says that the pain worsens when he eats, particularly when he eats fatty meals. He has noticed that his stool has been an unusual clay color recently. You perform an ultrasound of his abdomen and find that gallstones are blocking his common bile duct, preventing bile from entering the duodenum.

You test Mr. Williams's stool and find high amounts of undigested fats. Explain this finding.

Mr. Williams presents to your clinic with a complaint of abdominal pain in the right upper quadrant. He says that the pain worsens when he eats, particularly when he eats fatty meals. He has noticed that his stool has been an unusual clay color recently. You perform an ultrasound of his abdomen and find that gallstones are blocking his common bile duct, preventing bile from entering the duodenum.

Explain why his feces have become a clay color instead of a normal brown color.

Individuals experiencing prolonged vomiting lose a great deal of hydrochloric acid with the vomitus. Predict the effect this loss of acid will have on the pH of the blood. How will the respiratory system respond to the change in pH?

Irritant laxatives increase the amount of water in the feces by triggering an inflammatory response in the intestinal mucosa. Explain why an inflammatory response causes this effect.

Predict what types of nervous system damage might lead to a loss of the defecation reflex.

Your friend insists that absorption is the most important process carried out by the digestive system. What do you think of this claim? How would you respond?

A surgical procedure known as gastric bypass involves creating a small upper stomach pouch and attaching part of the small intestine to this pouch, “bypassing” the rest of the stomach and part of the duodenum.

Ms. Anthony has undergone gastric bypass. She goes out to dinner and eats an extremely large meal. Explain what will happen in her small and large intestines following this meal.

A surgical procedure known as gastric bypass involves creating a small upper stomach pouch and attaching part of the small intestine to this pouch, “bypassing” the rest of the stomach and part of the duodenum.

How would bypassing a significant portion of the stomach affect absorption of vitamin B12? Explain.

Trace the pathway that food takes through the entire alimentary canal, from the oral cavity to the anal canal.

Match the following digestive enzymes with the digestive reaction they catalyze.     

____Salivary amylase     

____Sucrase    

____Trypsin     

____Pancreatic lipase     

____Pancreatic amylase     

____Pepsin

a. Breaks down sucrose into glucose and fructose in small intestine

b. Digests lipids in small intestine

c. Breaks down proteins into polypeptides in stomach

d. Breaks down polysaccharides into oligosaccharides in small intestine

e. Assists in protein digestion in small intestine and activates other protein-digesting enzymes

f. Breaks down polysaccharides into oligosaccharides in the mouth

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

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

The mucosa from the stomach to the anus consists of an inner layer of stratified columnar epithelium.

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

The muscularis externa of most of the alimentary canal consists of inner circular and outer longitudinal layers of smooth muscle.

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

c. The soft palate and uvula move posteriorly during swallowing to prevent food from entering the laryngopharynx.

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

The mucosa of the esophagus, pharynx, and oral cavity contains simple squamous epithelium to protect it from abrasion.

The primary hormone that triggers the secretion of pancreatic juice and bile is:

a. Gastric inhibitory peptide

b. Cholecystokinin

c. Motilin

d. Somatostatin

Which of the following is not one of the functions of the bacterial flora of the large intestine?

a. Metabolism of undigested carbohydrates

b. Deterring the growth of harmful bacteria

c. Chemical digestion of dietary proteins

d. Stimulation of the immune system

e. Vitamin production

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.

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

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

Which of the following statements about accessory organ secretions is not true?

a. Hepatocytes produce bile, which drains out of the liver via the common hepatic ducts.

b. Saliva contains secretory IgA and lysozyme, which play an important role in preventing the growth of pathogenic bacteria in the oral cavity.

c. Pancreatic juice contains digestive enzymes and bicarbonate ions to neutralize the acidic chyme.

d. The gallbladder produces bile, which drains out of the gallbladder via the cystic duct.

Which of the following is not one of the six basic processes carried out by the digestive system?

a. Propulsion

b. Gas exchange

c. Secretion

d. Absorption

Defecation is stimulated by:

a. stretch receptors in the rectum, initiating the defecation reflex in the spinal cord.

b. segmentation of haustra in the proximal large intestine.

c. contraction of the external anal sphincter.

d. activation of the defecation reflex by the presence of fecal material in the proximal large intestine.

Which of the following best describes the microscopic structure of the liver?

a. Hexagonal plates of hepatocytes surrounding a central vein with portal triads at each corner

b. Octagonal plates of hepatocytes surrounding a central artery with portal triads at each corner

c. Irregular groups of hepatocytes surrounding a central vein with bile ducts at each corner

d. Hexagonal plates of hepatocytes surrounding a portal vein with bile ducts at each corner

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

Motility of the alimentary canal is regulated by the enteric nervous system, the parasympathetic nervous system, and hormones.

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

b. The esophageal and pharyngeal phases of swallowing are mediated by the swallowing reflex of the brainstem and the enteric nervous system.