Question 1

Villi and microvilli that are associated with the luminal surface of the intestinal epithelium are important in that they

Accepted Answer

Villi and microvilli increase the surface area available for absorption, allowing for more efficient absorption of nutrients and other substances from the digestive tract.

B) Stratified epithelial cells are not typically found in the intestinal epithelium.

C) Transport of substances from the epithelial cells into the circulatory system is accomplished through other structures such as capillaries and lymphatic vessels, not the villi and microvilli.

D) Cilia are not found on the villi and microvilli of the intestinal epithelium.

Question 2

What is the function of goblet cells of the stomach epithelium?

Accepted Answer

Goblet cells of the stomach epithelium secrete mucus to protect the stomach lining from the acidic environment.

Question 3

Cholecystokinin (CCK)stimulates the release of numerous digestive enzymes.Which of the following digestive enzymes is NOT released by CCK?

Accepted Answer

Cholecystokinin does not stimulate the release of pepsin, which is produced and released by the stomach. Chymotrypsin, pancreatic amylase, and elastase are all released by the pancreas in response to CCK.

Question 4

If there is a strong genetic link for type II diabetes mellitus in your family,how might you minimize your risk of developing the disorder?

Accepted Answer

Diet and exercise are the best ways to minimize the risk of developing type II diabetes mellitus, even if there is a strong genetic link. Eating a balanced diet with a limited amount of refined and sugary foods and engaging in regular physical activity can improve insulin sensitivity and help maintain a healthy weight, reducing the risk of developing diabetes. Monitoring blood glucose levels and taking insulin may be necessary for people who have already been diagnosed with diabetes, but they are not effective preventative measures. Eating carbohydrates like starch instead of sweets may be a good dietary choice, but it is not a comprehensive solution to minimizing the risk of developing diabetes.

Question 5

The stomach is highly acidic,creating a hostile environment for invading bacteria.Another function of the acidic environment is to activate the enzyme that initiates protein digestion in the stomach.What proteolytic enzyme is activated by the acidic environment?

Accepted Answer

Pepsin is the proteolytic enzyme that is activated by the acidic environment in the stomach. It breaks down proteins into smaller peptides.

Question 6

Why did scientists originally hypothesize that proteolytic enzymes like pepsin and trypsin are secreted in inactive form?

Accepted Answer

Scientists hypothesized that proteolytic enzymes like pepsin and trypsin are secreted in an inactive form because if they were secreted in an active form, they would digest the very tissues that synthesize them, leading to significant harm to the organism.

Question 7

Bile,which is synthesized in the liver and stored in the gallbladder,is important in lipid digestion.What feature/function of bile makes it an effective emulsifying agent?

Accepted Answer

Bile is an amphipathic molecule, meaning it has both hydrophobic and hydrophilic regions. This allows bile to interact with both lipids and water, forming micelles that help to emulsify fats and facilitate their digestion and absorption in the small intestine. The hydrophobic regions of bile interact with the hydrophobic tails of lipids, while the hydrophilic regions face outward and interact with water, forming a stable emulsion.

Question 8

Aquaporins have been identified in the epithelium of the large intestine.What is the function of these aquaporins?

Accepted Answer

Aquaporins are specialized channels that allow water to passively diffuse across cell membranes. In the large intestine, aquaporins facilitate the reabsorption of water that was not absorbed in earlier stages of digestion, preventing dehydration and ensuring proper stool consistency.

Question 9

Glucose is transported from the intestinal lumen into epithelial cells through ________ and from the intestinal epithelium into circulation by ________.

Accepted Answer

Glucose is transported from the intestinal lumen into epithelial cells through cotransport with sodium (a process known as secondary active transport, utilizing the sodium gradient established by the Na+/K+ ATPase pump), and from the intestinal epithelium into the circulation by facilitated diffusion, which does not require energy.

Question 10

Which of the following words best completes this sentence? The human body cannot ________ essential nutrients.

Accepted Answer

The human body cannot make essential nutrients; they must be obtained through diet.

Question 11

Figure 43.3 
-Following a meal high in starch,digestive processes break the starch into ________,which when absorbed into circulation cause a release of the hormone ________.

Accepted Answer

Starch is broken down into glucose during digestion. When absorbed into circulation, glucose causes a release of insulin from the pancreas, which helps to lower blood sugar levels by allowing cells to take up the glucose for energy or storage.

Question 12

Vitamin D is indirectly responsible for calcium uptake in the intestine.What is the mechanism by which Vitamin D and its receptor affect the calcium transporter gene?

Accepted Answer

Vitamin D and its receptor affect the calcium transporter gene through gene expression, which increases the production and activity of the calcium transporter protein in the intestinal cells.

Question 13

Which of the following is a major function of the small intestine?

Accepted Answer

The small intestine is responsible for absorbing the end-products of digestion, including nutrients such as carbohydrates, proteins, and fats. It is not responsible for initiating protein digestion or producing and storing bile. While bile aids in fat absorption, it is actually produced by the liver and stored in the gallbladder before being released into the small intestine.

Question 14

Amino acids,dipeptides,and sugars are transported from intestinal epithelial cells into circulation.Lipids are transported from the intestinal epithelium into

Accepted Answer

Lipids are transported from the intestinal epithelium into the lymph system, not directly into circulation. From the lymph system, lipids eventually enter into the bloodstream.

Question 15

Helicobacter pylori is a bacterial organism that causes ulcers and digestive disturbances.How might they survive the acid pH of the stomach?

Accepted Answer

Helicobacter pylori is able to survive in the acidic environment of the stomach by burrowing under the mucus layer that covers the stomach epithelium. This layer provides a protective barrier from the acidic contents of the stomach. Additionally, H. pylori is able to produce urease, which allows it to break down urea and generate ammonia, raising the local pH around the bacteria and providing a more suitable environment for survival.

Question 16

The stomach releases hydrochloric acid to create an acidic environment.Which cells release acid?

Accepted Answer

Parietal cells in the stomach release hydrochloric acid to create an acidic environment needed for the digestion of food.

Question 17

The parietal cells that line the stomach secrete hydrogen ions into the stomach against a concentration gradient.Based on that knowledge,which of the following transport processes is most likely involved in hydrogen ion secretion?

Accepted Answer

According to the statement, the parietal cells secrete hydrogen ions against a concentration gradient. This means that the process requires energy expenditure to move the ions from an area of low concentration to an area of high concentration. Active transport is the only transport process that requires energy and moves molecules against the concentration gradient. Therefore, active transport is the most likely process involved in hydrogen ion secretion.

Question 18

A major risk factor for atherosclerosis is high levels of dietary cholesterol.If you get your lipid levels checked regularly,which of the following,when elevated,most significantly increases your risk for developing atherosclerosis?

Accepted Answer

LDL cholesterol is known as "bad" cholesterol because it can build up in the walls of arteries, leading to atherosclerosis. Elevated levels of LDL cholesterol are a significant risk factor for developing this condition. HDL cholesterol, on the other hand, is known as "good" cholesterol because it can help remove excess cholesterol from the body, reducing the risk of atherosclerosis. Liver LDL receptors play a crucial role in regulating LDL cholesterol levels, but elevated levels of these receptors themselves do not increase the risk for atherosclerosis. Cholecystokinin is a hormone that regulates digestion and has no direct connection to atherosclerosis risk.

Question 19

Ruminants have a multi-compartmented stomach.They have a symbiotic relationship with bacterial organisms resident in the first of four compartments (the rumen).How do the bacteria help ruminant digestion?

Accepted Answer

The bacterial organisms in the first compartment (rumen) of a ruminant's stomach break down cellulose, which is a complex polysaccharide that would be indigestible without the assistance of these bacterial organisms. This allows the ruminant to obtain nutrients from foods that would otherwise be inaccessible.

Question 20

Figure 43.3 
-Based on the graph in the Figure 43.3,what can you infer about the incidence of type II diabetes mellitus?

Accepted Answer

The graph shows a clear correlation between obesity and the incidence of type II diabetes mellitus. As the percentage of obese individuals increases, so does the incidence of type II diabetes mellitus. This suggests that obesity is a significant risk factor for developing type II diabetes mellitus. The graph does not provide evidence to support choices B, C, or D.

Quiz 43: Animal Nutrition

Villi and microvilli that are associated with the luminal surface of the intestinal epithelium are important in that they

What is the function of goblet cells of the stomach epithelium?

Cholecystokinin (CCK) stimulates the release of numerous digestive enzymes.Which of the following digestive enzymes is NOT released by CCK?

If there is a strong genetic link for type II diabetes mellitus in your family,how might you minimize your risk of developing the disorder?

The stomach is highly acidic,creating a hostile environment for invading bacteria.Another function of the acidic environment is to activate the enzyme that initiates protein digestion in the stomach.What proteolytic enzyme is activated by the acidic environment?

Why did scientists originally hypothesize that proteolytic enzymes like pepsin and trypsin are secreted in inactive form?

Bile,which is synthesized in the liver and stored in the gallbladder,is important in lipid digestion.What feature/function of bile makes it an effective emulsifying agent?

Aquaporins have been identified in the epithelium of the large intestine.What is the function of these aquaporins?

Glucose is transported from the intestinal lumen into epithelial cells through and from the intestinal epithelium into circulation by .

Which of the following words best completes this sentence? The human body cannot ________ essential nutrients.

Figure 43.3 -Following a meal high in starch,digestive processes break the starch into ,which when absorbed into circulation cause a release of the hormone .

Vitamin D is indirectly responsible for calcium uptake in the intestine.What is the mechanism by which Vitamin D and its receptor affect the calcium transporter gene?

Which of the following is a major function of the small intestine?

Amino acids,dipeptides,and sugars are transported from intestinal epithelial cells into circulation.Lipids are transported from the intestinal epithelium into

Helicobacter pylori is a bacterial organism that causes ulcers and digestive disturbances.How might they survive the acid pH of the stomach?

The stomach releases hydrochloric acid to create an acidic environment.Which cells release acid?

The parietal cells that line the stomach secrete hydrogen ions into the stomach against a concentration gradient.Based on that knowledge,which of the following transport processes is most likely involved in hydrogen ion secretion?

A major risk factor for atherosclerosis is high levels of dietary cholesterol.If you get your lipid levels checked regularly,which of the following,when elevated,most significantly increases your risk for developing atherosclerosis?

Ruminants have a multi-compartmented stomach.They have a symbiotic relationship with bacterial organisms resident in the first of four compartments (the rumen) .How do the bacteria help ruminant digestion?

Figure 43.3 -Based on the graph in the Figure 43.3,what can you infer about the incidence of type II diabetes mellitus?

Quiz 43: Animal Nutrition

Villi and microvilli that are associated with the luminal surface of the intestinal epithelium are important in that they

What is the function of goblet cells of the stomach epithelium?

Cholecystokinin (CCK) stimulates the release of numerous digestive enzymes.Which of the following digestive enzymes is NOT released by CCK?

If there is a strong genetic link for type II diabetes mellitus in your family,how might you minimize your risk of developing the disorder?

The stomach is highly acidic,creating a hostile environment for invading bacteria.Another function of the acidic environment is to activate the enzyme that initiates protein digestion in the stomach.What proteolytic enzyme is activated by the acidic environment?

Why did scientists originally hypothesize that proteolytic enzymes like pepsin and trypsin are secreted in inactive form?

Bile,which is synthesized in the liver and stored in the gallbladder,is important in lipid digestion.What feature/function of bile makes it an effective emulsifying agent?

Aquaporins have been identified in the epithelium of the large intestine.What is the function of these aquaporins?

Glucose is transported from the intestinal lumen into epithelial cells through ________ and from the intestinal epithelium into circulation by ________.

Which of the following words best completes this sentence? The human body cannot ________ essential nutrients.

Figure 43.3 -Following a meal high in starch,digestive processes break the starch into ________,which when absorbed into circulation cause a release of the hormone ________.

Vitamin D is indirectly responsible for calcium uptake in the intestine.What is the mechanism by which Vitamin D and its receptor affect the calcium transporter gene?

Which of the following is a major function of the small intestine?

Amino acids,dipeptides,and sugars are transported from intestinal epithelial cells into circulation.Lipids are transported from the intestinal epithelium into

Helicobacter pylori is a bacterial organism that causes ulcers and digestive disturbances.How might they survive the acid pH of the stomach?

The stomach releases hydrochloric acid to create an acidic environment.Which cells release acid?

The parietal cells that line the stomach secrete hydrogen ions into the stomach against a concentration gradient.Based on that knowledge,which of the following transport processes is most likely involved in hydrogen ion secretion?

A major risk factor for atherosclerosis is high levels of dietary cholesterol.If you get your lipid levels checked regularly,which of the following,when elevated,most significantly increases your risk for developing atherosclerosis?

Ruminants have a multi-compartmented stomach.They have a symbiotic relationship with bacterial organisms resident in the first of four compartments (the rumen) .How do the bacteria help ruminant digestion?

Figure 43.3 -Based on the graph in the Figure 43.3,what can you infer about the incidence of type II diabetes mellitus?

Glucose is transported from the intestinal lumen into epithelial cells through and from the intestinal epithelium into circulation by .

Figure 43.3 -Following a meal high in starch,digestive processes break the starch into ,which when absorbed into circulation cause a release of the hormone .