Chapter 23 - Digestive System - Mastering A&P

Which major process involves the removal of water from intestinal contents? absorption defecation ingestion mechanical breakdown

Where does the process of segmentation occur? small intestine anus stomach esophagus

How would you classify chewing food? propulsion mechanical breakdown ingestion digestion

Which of the following functions is NOT correctly matched with its description? absorption; passage of digested nutrients into the blood or lymph mechanical breakdown: churning movements in the GI tract propulsion: physical breakdown of ingested food in the GI tract ingestion: intake of food nutrients

Which of the following is NOT a means of mechanically breaking down food? segmentation churning peristalsis mastication

Which organ of the digestive tract is the body's major digestive organ? small intestine liver large intestine stomach

Which of the following is the best illustration of the difference between metabolism and digestion? Digestions must happen first for metabolism to follow it. Digestion requires enzymes for it to take place while metabolism does not necessarily need or use them. Metabolism comprises all of the chemical reactions preformed with in the body while digestion is only the breakdown of food within the GI tract. Digestion has a wide variety of chemical reactions while metabolism is restricted to only a few reaction types.

Which of the following is least involved in the mechanical breakdown of food, digestion or absorption of nutrients? the small intestine the esophagus large intestine the oral cavity

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

Peristaltic waves are ________. waves of muscular contractions that propel contents from one point to another pendular movements of the gastrointestinal tract churning movements of the gastrointestinal tract segmental regions of the gastrointestinal tract

The chemical processes of food breakdown are called ________. ingestion secretion digestion absorption

Chemical digestion reduces large complex molecules to simpler compounds by the process of ________. catabolism anabolism mastication fermentation

When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________. digestion mechanical breakdown secretion absorption

In a patient suffering from untreated infection-induced peritonitis, an infection in the visceral peritoneum immediately ______. spreads directly to the parietal peritoneum spreads directly to the retroperitoneal organs causes appendicitis All of the listed responses are correct.

Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium? ** muscularis externa mucosa submucosa serosa

Which layer of the alimentary canal is responsible for segmentation and peristalsis? mucosa submucosa muscularis externa serosa

Which layer of the alimentary canal contains not only glands and blood vessels but also a nerve plexus that helps regulate digestive activity? mucosa submucosa serosa muscularis externa

Peritoneal organs are completely covered in a serous membrane and have a dorsal and ventral mesentery. True False

The __________ is the serous membrane that lines the abdominal organs. mesentery visceral peritoneum omenta parietal peritoneum

Which layer of the digestive tract controls digestive propulsion? muscularis externa serosa submucosa mucosa

Select the description below that illustrates a difference between a sphincter and circular muscle. 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. Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions. A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue. Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract.

The lamina propria is composed of ________. reticular connective tissue dense irregular connective tissue loose connective tissue dense regular connective tissue

The sheets of peritoneal membrane that hold the digestive tract in place are called ________. mesenteries serosal lining lamina propria mucosal lining

The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________. lamina propria submucosa serosa adventitia

The outermost tissue layer of the alimentary canal is the __________. serosa submucosa muscularis mucosa

The palatine tonsils are located between which two structures? the soft palate and the hard palate the tongue and the floor of the oral cavity the palatopharyngeal arch and the throat the palatopharyngeal arch and the palatoglossal arch

The uvula is an extension of the __________. palatopharyngeal arch oral vestibule soft palate lingual frenulum

Which of the following is NOT a function of saliva? Saliva moistens food and helps compact it into a bolus. Saliva cleanses the mouth. Saliva dissolves food chemicals so that they can be tasted. Saliva contains enzymes that begin the chemical breakdown of proteins.

Which of the following inhibits salivation? ingestion of spicy foods relaxing after a meal the sight or smell of food being stressed or frightened

Where do the ducts of the submandibular salivary glands empty into the oral cavity? the floor of the mouth under the tongue along the upper surface of the tongue the base of the lingual frenulum the vestibule near the upper molars

How many total permanent teeth should an adult have, assuming none have been lost or removed? 8 16 20 32

How are wisdom teeth (third molars) classified? as permanent teeth as primary teeth as incisors as milk teeth

Which teeth are best suited for cutting or nipping off pieces of food in the permanent dentition? incisors molars canines premolars (bicuspids)

The deciduous dentition consists of __________ teeth. 10 16 20 32

Which digestive process does NOT occur in the mouth? digestion segmentation ingestion mechanical breakdown

What part of the tooth bears the force and resists the friction of chewing? enamel pulp crown cementum

Which of the following is not true of saliva? moistens food and aids in compacting of the bolus contains enzymes that begin the breakdown of carbohydrates contains acids which aid in chemical digestion cleanses the mouth

A child with restricted tongue movement may have a surgery that involves the cutting of the ________. terminal sulcus palatine tonsils lingual frenulum uvula

Which of these is not a component of saliva? lysozyme a cyanide derivative metabolic waste defensins

Select the statement that is true concerning primary teeth. There are 27 primary teeth, and the molars are permanent. There are 20 primary teeth, and by 24 months of age most children have all 20. There are 24 primary teeth, and no new primary teeth appear after 13 months. There are 32 primary teeth, and by 36 months of age, most children have all 32.

Which of the following is true concerning the number and type of permanent teeth? There are 32 permanent teeth, and the wisdom teeth are the last to emerge. The number of permanent teeth is always equal to the number of primary teeth. There are 27 permanent teeth, and the first molars are usually the last to emerge. The number of upper permanent teeth is not equal to the number of lower permanent teeth.

What control mechanism opens the gastroesophageal sphincter? peristalsis in the esophagus constriction of the upper esophageal sphincter pH changes in the esophagus detection of nutrients in the esophagus

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

Gastric juice does not typically cause a burning sensation within the stomach. But reflux of this gastric juice into the esophagus can cause a burning sensation. One reason why this occurs is that the esophagus ______. secretes mucus that is not identical to stomach mucus is internally lined by epithelial cells that are in direct physical contact with the contents of the esophagus has enzymes that react with stomach acid to cause a burning sensation None of the listed responses is correct.

In a patient suffering from a gastric ulcer caused by Helicobacter pylori, the cells most likely to have been damaged first are the ______. enteroendocrine cells parietal cells chief cells mucous cells

Which layer of the stomach contains the gastric pits that secrete mucous, acid, and digestive enzymes? serosa mucosa muscularis externa submucosa

Which of these structures is found in the stomach but nowhere else in the alimentary canal? a lining of columnar epithelium a circular muscle layer mucus-forming cells an oblique muscle layer

Which area of the stomach adjoins the small intestine? body fundus pylorus cardia

Chief cells secrete inactive pepsinogen in order to prevent acid erosion inside of the chief cells. True False

The intestinal phase of stomach digestion is triggered by partially digested nutrients filling the pylorus. True False

Which of the following is NOT a characteristic of the stomach? The stomach mucosa is folded into rug. The stomach produces a double-layered coat of alkaline mucus. The stomach has three layers of muscle in the muscularis tunic. The stomach releases enzymes to digest carbohydrates.

In the __________ phase of gastric secretion, chyme is moved into the duodenum. reflux intestinal cephalic gastric phase

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. Many potentially harmful bacteria will be prevented entry to the small intestine by stomach acid. Stomach acid denatures proteins making the polypeptide chain more accessible to pepsin digestive enzymes. Low pH converts pepsinogen to its active form, pepsin. The stomach's acid catabolically breaks down foodstuffs in preparation for absorption.

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. This is an example of a long reflexive pathway. The motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system. This prepares the stomach for food before its arrival in the stomach. The cerebral cortex, hypothalamus and medulla oblongata are all involved in processing the stimulatory information.

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? parietal cells surface epithelial cells mucous neck cells chief cells

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

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

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

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. More stomach acid will be produced and secreted. Protein digestion will be enhanced. Digestive enzymes will be released. A positive feedback response will be initiated and G-cell activity will continue to go up.

Which of the following is not a factor that helps create the stomach mucosal barrier? replacing of damaged epithelial mucosa cells secretion of pepsinogen tight junctions of epithelial mucosa cells thick coating of bicarbonate-rich mucus

The bolus is liquefied in the ________ and it is now called chyme. mouth esophagus small intestine stomach

Pepsinogen, an inactive digestive enzyme, is secreted by the ________. Brunner's glands goblet cells of the small intestine parietal cells of the duodenum chief cells of the stomach

Which vitamin requires intrinsic factor in order to be absorbed? A B12 C K

The ingestion of a meal high in fat content would cause which of the following to occur? The acid secretions from the stomach would be sufficient to digest this food but may cause heartburn. Bile would be released from the gallbladder to emulsify the fat in the duodenum. This type of food would cause secretion of gastrin to cease, resulting in faster gastric emptying. Increased production of trypsinogen.

Chief cells ________. produce pepsinogen produce mucin produce gastrin produce HCl

Which of the following is (are) not important as a stimulus in the gastric phase of gastric secretion? distention low acidity peptides carbohydrates

Which of the following produce intrinsic factor? mucous neck cells parietal cells zymogenic cells enteroendocrine cells

What stomach secretion is needed to produce mature erythrocytes? intrinsic factor gastric amylase pepsinogen gastric lipase

Select the correct statement about the regulation of gastric secretion. Gastric secretion is enhanced by very low pH (below a pH of 2). The presence of food in the stomach prevents hormonal control of gastric secretion. Vagus stimulation of the stomach results in decreased secretion of gastric juice. Gastric secretion can be stimulated before food has entered the mouth.

Hormones or paracrines that inhibit gastric secretion include ________. gastrin ACh secretin histamine

Which chemical activates the transformation of trypsinogen to trypsin? amylase carboxypeptidase chymotrypsin enteropeptidase

What is a major function of pancreatic juice? neutralizing chyme entering the small intestine from the stomach acidifying the contents of the stomach acidifying the contents of the small intestine emulsifying fats by breaking them into smaller pieces

What triggers the release of secretin from the small intestine? presence of bile in the small intestine the presence of acidic, fatty chyme in the small intestine presence of cholecystokinin (CCK) in the small intestine presence of carbohydrates in the small intestine

Bile is produced by the __________ under hormonal influence of __________. pancreas; secretin liver; secretin gallbladder; CCK small intestine; CCK

The pancreas secretes __________. procarboxypeptidase cholecystokinin (CCK) bile secretin

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

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

Digestion and absorption of which of the following would be affected the most if the liver were severely damaged? starches proteins lipids carbohydrates

What structural modification of the small intestine slows the movement of chyme through the lumen? circular folds intestinal crypts villi microvilli

Which cells in the small intestine's mucosa secrete mucus? Paneth cells goblet cells enteroendocrine cells enterocytes

Which of these best describes a lacteal? a projection of the small intestine wall designed to increase surface area a deep pocket in the intestinal wall where endocrine and antimicrobial cells are located special capillaries in the villi designed for absorbing food effectively a lymphatic vessel designed to help introduce fats to the blood

The __________ is the first segment of the small intestine. duodenum colon jejunum ileum

Which of the following is NOT a structural modification of the small intestine that increases surface area? rugae microvilli circular folds villi

Most absorption of nutrients occurs in the __________. jejunum large intestine duodenum stomach

Which other organ can affect small-intestine motility? large intestine mouth stomach pancreas

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 digestive systems first and foremost job is to digest and absorb nutrients so it puts off immunity for last. The body will actively excrete pathogens out the body, into the digestive system to be removed from the body in feces. 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. The alkaline secretion of the small intestine aid in the growth of bacteria and must be controlled.

The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task? Brunner's glands and Peyer Patches villi, and microvilli the vast array of digestive enzymes the rugae and haustra

A patient has esophageal cancer and must have a feeding tube inserted. The nurse tells the patient that the tube will be inserted surgically into the duodenum. The patient's wife asks why the tube will not be inserted into the stomach. What should the nurse say? The stomach's acid will digest the tube, leading to possible infections through the degraded tube. Contraction of the muscles in the stomach wall will interfere with the delivery of the food through the tube. Insertion of a tube into the stomach will likely cause gastric ulcers. There is less risk for vomiting, which could cause complications. Digestion is also completed in the small intestines, so there is no need for the stomach with a liquid food diet.

The function of the goblet cells is to ________. absorb nutrients from digested food and store them for future use produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion secrete buffers in order to keep the pH of the digestive tract close to neutral provide protection against invading bacteria and other disease-causing organisms that enter the digestive tract in food

Paneth cells ________. secrete bicarbonate ions secrete digestive enzymes secrete enzymes that kill bacteria secrete hormones

The appendix contains masses of lymphoid tissue and therefore has leukocytes capable of attacking bacteria present in the appendix. But during appendicitis, bacteria trapped in the lumen of the appendix are not effectively attacked because ______. these bacteria are resistant to attack these bacteria are not resistant but they are immune to attack by the leukocytes there is an inadequate blood supply to the appendix wall feces provide protection to the bacteria

The formation of diverticula involves, most significantly, the ______. atrophy of the muscular externa atrophy of the mucosa weakening of the colon's submucosa thickening of the serosa

Which of the following propels food residue over large areas of the colon three to four times a day? Valsalva's maneuver haustral contractions mass movement defecation reflex

As wastes navigate the large intestine, which features do they pass through, in order? the sigmoid, left colic, and right colic flexures the cecum, left colic, and right colic flexures the sigmoid, right colic, and left colic flexures the right colic, left colic, and sigmoid flexures

Which of the following is the primary physiological function of the large intestine? mechanical breakdown of food nutrient absorption water absorption and feces elimination primary digestion of food

Which of the following is NOT a function of the large intestine? absorption of water production of intrinsic factor absorption of vitamins absorption of electrolytes

Bacteria that reside in the large intestine make vitamin C. True False

__________ can result if food passes too slowly through the large intestine. Colitis Irritable bowel syndrome Diarrhea Constipation

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

Which of the following is an essential role played by large intestine bacteria? produce gas synthesize vitamins C and D absorb bilirubin fermentation of indigestible carbohydrates

Which of the following is not characteristic of the large intestine? It ________. is longer than the small intestine has pocket-like sacs called haustra exhibits external muscular bands called teniae coli does not contain villi

An effective way to medically treat diarrhea would be to use a drug that ______. increases the activity of the longitudinal layer of the muscular increases the activity of the parasympathetic division of the ANS inhibits muscle tone in the anal sphincters inhibits the activity of the myenteric nerve plexus

One of the direct consequences of lactose intolerance is ______. increased intestinal absorption of this disaccharide increased osmotic pressure of the large intestine contents decreased motility of the small and large intestines increased blood glucose levels

Carbohydrates are digested into __________. glycerol amino acids nucleotides monosaccharides

Which of the following are NOT correctly matched? nuclease: DNA and RNA digestion protease: lipid digestion lipase: fat digestion amylase: carbohydrate digestion

Which enzyme(s) is/are responsible for the chemical breakdown of carbohydrates? amylases trypsin proteases nuclease

How are fats absorbed into the lymph? in the form of glycerol in the form of chylomicrons in the form of fatty acids and glycerol in the form of micelles

Which water-soluble vitamins are absorbed in the small intestines? vitamins A and E vitamins C and D B complex and C vitamins B complex and D vitamins

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 ________. lipid digestion lipid ingestion lipid emulsification lipid absorption

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

Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible? lipase amylase chymotrypsin pepsin

Which of the following enzymes would be most active in the presence of a high concentrations of protein fragments? trypsin dextrinase lipase amylase

Select the correct statement about absorption. Carbohydrates diffuse across the mucosal endothelium and are then actively transported into blood capillaries. In the rare case that intact, whole proteins are transported across the mucosal endothelium, an immune response may be generated. Eighty percent of ingested materials have been absorbed by the end of the large intestine. Amino acid transport is linked to chloride transport.

You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal? gastrin trypsin cholecystokinin amylase

Select the correct statement about electrolyte absorption. If vitamin B is not present, calcium is not absorbed. Iron and calcium are absorbed mostly by the duodenum. Potassium moves across the epithelium by active transport. Chloride ion absorption is coupled to glucose and amino acid transport.