Question 1

Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________.
A) speed the churning of the stomach
B) increases the output of stomach acid
C) speed the activity of the jejunum
D) slow the activities of the stomach

Accepted Answer

Secretin and cholecystokinin are released in response to the arrival of acidic chyme in the duodenum. These hormones slow down the activities of the stomach, inhibit gastric acid secretion, and stimulate bile and pancreatic enzyme secretion to aid in the digestion of fats and proteins in the small intestine. Therefore, the correct choice is D- slow the activities of the stomach.

Question 2

All of the following are true of swallowing (deglutition)except one.Select the statement that is not true of swallowing.
A) The involuntary portion of swallowing takes place in the pharynx.
B) The mouth, pharynx and esophagus all take part in swallowing.
C) The epiglottis assists in propelling food into the trachea.
D) The voluntary phase of swallowing takes place within the mouth.

Accepted Answer

The epiglottis actually prevents food from entering the trachea by covering the opening of the trachea during swallowing.

Question 3

Select the one response below that would not result from a drug that blocks histamine receptors in the cells lining the stomach.
A) It would reduce the symptoms of heartburn.
B) It would cause the release of secretin and cholecystokinin.
C) It would lower the activity of parietal cells.
D) It would raise the pH of the stomach.

Accepted Answer

Blocking histamine receptors in the cells lining the stomach would reduce acid secretion by parietal cells and ultimately raise the pH of the stomach, leading to a reduction in the symptoms of heartburn. However, it would not cause the release of secretin and cholecystokinin, which are hormones that stimulate pancreatic secretion and bile release. Therefore, the correct choice is B.

Question 4

A ruptured appendix is life threatening because ________.
A) it is likely to cause severe internal bleeding
B) the large intestine will no longer be able to receive digested material from the small intestine
C) loss of the appendix's function will cause an immune deficiency in the digestive system
D) it is likely to cause massive infection of the abdominopelvic cavity

Accepted Answer

A ruptured appendix can cause the release of bacteria and fecal matter into the abdominopelvic cavity, leading to a potentially fatal condition called peritonitis. This can result in massive infection and inflammation throughout the abdomen, impacting other vital organs and leading to sepsis, shock, and even death. Internal bleeding may also occur as a result of the ruptured appendix, but this is not the primary life-threatening concern. Option A is incorrect because it only addresses one potential complication of a ruptured appendix, while Option B focuses on a non-existent problem (the large intestine does not receive digested material from the small intestine). Option C is also incorrect because the appendix does not play a major role in immune function in the digestive system.

Question 5

Fat absorption through the plasma membrane of epithelial cells ________.
A) Is accomplished by cotransporters that use the concentration gradient of Na+ outside of the cells
B) requires vesicular, active transport of the relatively large fatty acids and monoglyceride
C) occurs by simple diffusion because lipids are able to penetrate the hydrophobic fatty acid tails within the plasma membrane
D) requires enzymes attached to the brush border to further breakdown the fats

Accepted Answer

Fat absorption through the plasma membrane of epithelial cells occurs by simple diffusion because lipids, being hydrophobic, can easily penetrate the hydrophobic fatty acid tails within the plasma membrane without the need for transport proteins or energy expenditure.

Question 6

The function of the hepatic portal circulation is to ________.
A) return glucose to the general circulation when blood sugar is low
B) carry toxins to the kidney for disposal through the urinary tract
C) distribute hormones throughout the body
D) collect absorbed nutrients for metabolic processing in the liver

Accepted Answer

The hepatic portal circulation is responsible for collecting absorbed nutrients from the intestines and bringing them to the liver for metabolic processing. This includes carbohydrates, proteins, and fats that have been broken down during digestion. The liver can then distribute these nutrients to the rest of the body or store them for later use.

Question 7

Select the description below that illustrates a difference between a sphincter and circular muscle.
A) A sphincter is a thickening of circular muscle that can prevent the movement of digesting materials while circular muscle is involved in propulsion digesting material.
B) Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract.
C) A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue.
D) Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions.

Accepted Answer

A sphincter is a specialized thickening of the circular muscle layer that can prevent the movement of digesting materials, while circular muscle is involved in the propulsion of digesting material. The other choices are either incorrect or incomplete in their descriptions.

Question 8

A doctor consulting a patient that recently has had their gall bladder removed would likely advise ________.
A) increasing unsaturated fats while eliminating trans fats in their diets
B) a low to no carb diet
C) fewer, but larger meals
D) eating foods that are low in fat

Accepted Answer

Since the gallbladder is responsible for storing and releasing bile to break down fats, patients who have had their gallbladder removed may have trouble digesting high-fat foods. Therefore, a doctor would advise eating foods that are low in fat.

Question 9

The sight of food can trigger a series of events that results in the release of gastric juice.All but one of the following is true in regards to the previous statement.Select the one answer that is not true.
A) This prepares the stomach for food before its arrival in the stomach.
B) This is an example of a long reflexive pathway.
C) The motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system.
D) The cerebral cortex, hypothalamus and medulla oblongata are all involved in processing the stimulatory information.

Accepted Answer

The motor nerves involved in triggering the release of gastric juice are part of the parasympathetic division of the autonomic nervous system, not the sympathetic division.

Question 10

Bile salts bind at their hydrophobic regions to large fat globules within the chyme that enters the duodenum.Bile salts break up the fat globule into smaller fat droplets.This role of bile salts is best described as ________.
A) lipid emulsification
B) lipid absorption
C) lipid ingestion
D) lipid digestion

Accepted Answer

Bile salts play a crucial role in the digestion of lipids by emulsifying large fat globules into smaller droplets, which increases the surface area for enzyme activity and enhances lipid digestion. Therefore, the best choice for this role is lipid emulsification (A). B, C, and D are incorrect because bile salts do not absorb or ingest lipids, nor do they directly digest them.

Question 11

Some antacid drugs block histamine receptors,resulting in reduction of the production and excretion of stomach acid.These drugs have the biggest effect on which of the following?
A) surface epithelial cells
B) chief cells
C) mucous neck cells
D) parietal cells

Accepted Answer

Parietal cells are responsible for the production and excretion of stomach acid, and antacid drugs that block histamine receptors have the biggest effect on these cells, leading to a reduction in acid production.

Question 12

In the enteric nervous system,a long reflexive pathway has an advantage over a short reflexive pathway in the fact that ________.
A) long reflexive pathways last much longer than short reflexive pathways
B) long reflexive pathways can respond throughout the entire length of the GI tract while short reflexive pathways can only respond in the proximal end
C) long reflexive pathways are quicker to respond than short reflexive pathways
D) long reflexive pathways can be stimulated by things outside of the GI tract

Accepted Answer

Long reflexive pathways involve the central nervous system and can be stimulated by external factors such as the sight, smell, or thought of food, unlike short reflexive pathways that are localized within the enteric nervous system of the GI tract.

Question 13

All but one of the following is a function of the low pH found in the stomach.Select the description below that does not reflect a role of stomach acid.
A) The stomach's acid catabolically breaks down food stuffs in preparation for absorption.
B) Stomach acid denatures proteins making the poly peptide chain more accessible to pepsin digestive enzymes.
C) Many potentially harmful bacteria will be prevented entry to the small intestine by stomach acid.
D) Low pH converts pepsinogen to its active form of pepsin, preventing the protease enzyme from digesting the cells that produce it.

Accepted Answer

Stomach acid does not catabolically break down food for absorption; it primarily aids in protein digestion and protects against pathogens.

Question 14

Which of the organs listed below is involved in all of the following processes: secretion,mechanical breakdown of food,digestion and absorption?
A) the stomach
B) the esophagus
C) the sigmoid colon
D) the large intestines

Accepted Answer

The stomach is involved in all of the listed processes - it secretes gastric juices to aid in digestion, mechanically breaks down food through muscle contractions, further digests food through chemical processes, and absorbs some nutrients. The esophagus only transports food and does not secrete any digestive juices, and the sigmoid colon and large intestines mainly absorb water and electrolytes, with limited digestion and no mechanical breakdown of food.

Question 15

Select the best explanation for why protease enzymes are secreted in inactive forms.
A) Inactive enzymes will simply be expelled with the feces if no protein is present in the digesting food, this will help to conserve energy.
B) The immunoglobulins protecting the digestive tract would be digested without proper regulation of protein digesting enzymes.
C) The enzymes would digest each other if they were not properly regulated.
D) The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract.

Accepted Answer

The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract. This ensures that the protease enzymes don't accidentally start breaking down proteins inside the cells producing them or in other parts of the body where protein breakdown is not desired. Once safely in the lumen, the enzymes can be activated to start digesting proteins. This helps to prevent damage to the body's own tissues and maximizes the efficiency of protein digestion in the small intestine.

Question 16

Which of the following is the best explanation of the benefit in the digestive system having the largest collection of lymphoid tissue (MALT)at the distal end of the small intestine?
A) The alkaline secretion of the small intestine aid in the growth of bacteria and must be controlled.
B) The body will actively excrete pathogens out the body, into the digestive system to be removed from the body in feces.
C) The huge numbers of bacteria living in the large intestine must be prevented from entering the lumen of the small intestine and being absorbed with food's nutrients into the blood stream.
D) The digestive systems first and foremost job is to digest and absorb nutrients so it puts off immunity for last.

Accepted Answer

The largest collection of lymphoid tissue (MALT) at the distal end of the small intestine is beneficial because it prevents the huge numbers of bacteria living in the large intestine from entering the lumen of the small intestine and being absorbed with food's nutrients into the blood stream. This helps to protect the body from harmful pathogens and maintain a healthy gut microbiome.

Question 17

The chemical and mechanical processes of food breakdown are called ________.
A) secretion
B) ingestion
C) absorption
D) digestion

Accepted Answer

The chemical and mechanical breakdown of food is called digestion. Ingestion refers to taking food into the mouth, absorption refers to the movement of nutrients from the digestive system into the bloodstream, and secretion refers to the release of fluids or enzymes from glands.

Question 18

The mechanical and chemical receptors that control digestive activity are located ________.
A) in the walls of the tract organs
B) in the glandular tissue that surround the organ lumen
C) in the oral cavity
D) in the pons and medulla

Accepted Answer

Mechanical and chemical receptors that control digestive activity are located in the walls of the tract organs, such as the stomach and small intestine, and they respond to stretching, osmolarity, and pH changes in the lumen. They can initiate or inhibit digestive activities, such as the secretion of digestive enzymes or the contraction of smooth muscle. Receptors in the oral cavity are involved in the initiation of the digestive reflexes, but they do not directly control digestive activity. Receptors in the brain stem, specifically the medulla and pons, receive sensory input from the digestive organs and are involved in regulating digestive activities.

Question 19

Proteins entering the stomach act as a buffer raising pH.Rising pH stimulates the activity of G-cells in the lining of the stomach.All of the following but one will occur.Select the statement below that would not occur.
A) More stomach acid will be produced and secreted.
B) A positive feedback response will be initiated and G-cell activity will continue to go up.
C) Protein digestion will be enhanced.
D) Digestive enzymes will be released.

Accepted Answer

A positive feedback response leading to further increase in G-cell activity is unlikely as the rise in stomach pH will eventually stabilize the activity of G-cells. However, the other statements are true - more stomach acid will be produced and secreted, protein digestion will be enhanced, and digestive enzymes will be released.

Question 20

Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________.
A) decrease the activities of the accessory digestive organs
B) increases stomach emptying
C) increase the force of stomach contractions
D) increase the release of digestive enzymes and bile

Accepted Answer

Secretin and cholecystokinin stimulate the release of digestive enzymes and bile from the pancreas and gallbladder, respectively, thus increasing the efficiency of digestion and absorption in the small intestine.

Quiz 23: The Digestive System

Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________.

All of the following are true of swallowing (deglutition) except one.Select the statement that is not true of swallowing.

Select the one response below that would not result from a drug that blocks histamine receptors in the cells lining the stomach.

A ruptured appendix is life threatening because ________.

Fat absorption through the plasma membrane of epithelial cells ________.

The function of the hepatic portal circulation is to ________.

Select the description below that illustrates a difference between a sphincter and circular muscle.

A doctor consulting a patient that recently has had their gall bladder removed would likely advise ________.

The sight of food can trigger a series of events that results in the release of gastric juice.All but one of the following is true in regards to the previous statement.Select the one answer that is not true.

Bile salts bind at their hydrophobic regions to large fat globules within the chyme that enters the duodenum.Bile salts break up the fat globule into smaller fat droplets.This role of bile salts is best described as ________.

Some antacid drugs block histamine receptors,resulting in reduction of the production and excretion of stomach acid.These drugs have the biggest effect on which of the following?

In the enteric nervous system,a long reflexive pathway has an advantage over a short reflexive pathway in the fact that ________.

All but one of the following is a function of the low pH found in the stomach.Select the description below that does not reflect a role of stomach acid.

Which of the organs listed below is involved in all of the following processes: secretion,mechanical breakdown of food,digestion and absorption?

Select the best explanation for why protease enzymes are secreted in inactive forms.

Which of the following is the best explanation of the benefit in the digestive system having the largest collection of lymphoid tissue (MALT) at the distal end of the small intestine?

The chemical and mechanical processes of food breakdown are called ________.

The mechanical and chemical receptors that control digestive activity are located ________.

Proteins entering the stomach act as a buffer raising pH.Rising pH stimulates the activity of G-cells in the lining of the stomach.All of the following but one will occur.Select the statement below that would not occur.

Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________.