Question 1

The mucus-producing cells that line the stomach

Accepted Answer

The mucus-producing cells that line the stomach lubricate and protect the stomach lining. This prevents the stomach acid from damaging the stomach tissue.

Question 2

The function of the sphincter between the stomach and small intestine is to

Accepted Answer

The sphincter between the stomach and small intestine, known as the pyloric sphincter, is responsible for periodically releasing chyme (partially digested food) into the small intestine in squirts. This allows for proper digestion and absorption of nutrients in the small intestine without overwhelming the digestive system. Option A is incorrect because pepsin digestion can also occur in the small intestine, not just in the stomach. Options C and D refer to other sphincters (the hepatopancreatic sphincter) responsible for releasing bile and pancreatic secretions into the duodenum, respectively.

Question 3

Most gastric ulcers are caused by

Accepted Answer

Most gastric ulcers are caused by a bacterium called Helicobacter pylori (H. pylori) which infects the lining of the stomach and weakens the protective mucus layer, making the stomach more prone to damage from stomach acid. Aspirin and ibuprofen, excessive mental stress, and overconsumption of alcohol can all worsen symptoms of gastric ulcers, but they are not the primary cause.

Question 4

The structure of the esophagus fits its function in that

Accepted Answer

The esophagus is responsible for moving food from the mouth to the stomach through a process called peristalsis, which involves rhythmic contractions of smooth muscle in the esophagus walls. Therefore, the structure of the esophagus with smooth muscle fits its function in transporting food. Choices A, C, and D are incorrect because the esophagus does not direct food to the lungs or stomach, it is not regulated by contractions in the pharynx, and its length does not determine the volume of food an animal can ingest.

Question 5

When the wall of the stomach cannot protect the organ from the effects of digestion, the result is

Accepted Answer

When the wall of the stomach cannot protect the organ from the effects of digestion, it can result in a gastric ulcer. Heartburn is caused by stomach acid refluxing into the esophagus, peristalsis is a normal muscular movement of the digestive system, and nausea can have many causes including infections, motion sickness, and certain medications.

Question 6

The secretory parietal cells of the stomach are responsible for producing

Accepted Answer

The secretory parietal cells of the stomach are responsible for producing hydrochloric acid.

Question 7

The tongue does all of the following except

Accepted Answer

While the tongue helps in mixing food with saliva, it is the salivary glands that secrete saliva, not the tongue. Therefore, option C is incorrect. The tongue is responsible for taste (option A), shaping food into a bolus (option B), and pushing food into the pharynx (option D).

Question 8

Lack of exercise and activity can be one of several reasons a person might become constipated, or be unable to have regular bowel movements. Which of the four stages of food processing is directly affected in this situation?

Accepted Answer

Lack of exercise and activity directly affects the stage of elimination, as it can result in slowed peristalsis (muscle contractions that move feces through the intestines) and ultimately constipation or irregular bowel movements.

Question 9

Which enzyme breaks large polypeptides into smaller polypeptides?

Accepted Answer

Chymotrypsin is a protease enzyme that breaks down large polypeptides into smaller polypeptides by cleaving peptide bonds. Amylase breaks down carbohydrates, lipase breaks down lipids, and lactase breaks down lactose.

Question 10

Which of the following mechanisms helps keep the stomach lining in place despite the destructive force of gastric juice?

Accepted Answer

The answer of Which of the following mechanisms helps keep...

Question 11

Heartburn is usually caused by the

Accepted Answer

Heartburn occurs when stomach acid refluxes into the lower esophagus, which is not equipped to handle exposure to acid. This causes irritation and a burning sensation.

Question 12

Epithelial cells lining the intestine have surface projections that increase the rate of nutrient absorption. These projections are called

Accepted Answer

The surface projections of the epithelial cells lining the intestine are called microvilli. These structures increase the surface area of the cells, allowing for more efficient absorption of nutrients. Villi are finger-like projections of tissue that contain blood vessels and lymphatic vessels. Cilia are hair-like structures that move in a coordinated manner to move substances along certain surfaces. Parietal cells are a type of cell found in the stomach that secretes hydrochloric acid.

Question 13

The epiglottis is a

Accepted Answer

The epiglottis is a flap of cartilage that covers the entrance to the trachea during swallowing to prevent food from entering the lungs.

Question 14

What is the main digestive function of the pancreas?

Accepted Answer

The main digestive function of the pancreas is to produce digestive enzymes and an alkaline solution. The enzymes help to break down carbohydrates, fats, and proteins in the small intestine, and the alkaline solution helps to neutralize stomach acid that enters the small intestine. The pancreas does not produce bile salts, bicarbonate-containing mucus, or aid in the control of cholesterol.

Question 15

Which of the following is important in the digestion of lipids?

Accepted Answer

Bile salts are important in the digestion of lipids because they emulsify the large lipid droplets into smaller ones, increasing the surface area available for enzyme action.

Question 16

Bile produced in the liver is stored in the ________ before entering the intestine.

Accepted Answer

Bile produced in the liver is stored in the gallbladder before entering the intestine.

Question 17

In the digestive system, most nutrient absorption occurs in the

Accepted Answer

The small intestine is where most nutrient absorption occurs. It has a large surface area due to its long length, many folds, and tiny projections called villi and microvilli, which allow for efficient absorption of nutrients from food. The stomach primarily breaks down food through the use of acid and enzymes, while the pancreas secretes digestive enzymes to help break down food in the small intestine. The large intestine primarily absorbs water and electrolytes, but not significant amounts of nutrients.

Question 18

Which of the following nutrients is digested only after it reaches the small intestine?

Accepted Answer

Fat requires enzymes from the pancreas and bile from the liver to be fully digested and absorbed, which occurs in the small intestine. The other options are digested in the stomach and/or small intestine.

Question 19

The stomach mixes food with secretions of the stomach wall to form

Accepted Answer

The mixture of food and secretions in the stomach forms chyme, which is a thick, semi-fluid substance that is released into the small intestine for further digestion and absorption of nutrients. Gastric juice is the name for the secretions of the stomach, but it is not the actual mixture of food and secretions. Parietal bolus is not a term used in the context of the digestive system. Gastrin is a hormone produced by cells in the stomach that helps to regulate the production of gastric juice.

Question 20

The Heimlich maneuver is performed to forcibly

Accepted Answer

The Heimlich maneuver involves forcibly elevating the diaphragm to create enough pressure to expel an object from the airway.

Quiz 21: Nutrition and Digestion