A&P II chapter 22 Digestion
Antibodies are produced by B cells of the immune system in response to specific antigens. In celiac disease, the immune system recognizes gluten as an allergen and produces antibodies against it.
A blood test that can be used to see if celiac disease is possible is the tissue transglutaminase (tTG)-IgA antibodies (tTG-IgA test). Why do you think this test is a good tool as a screening for possible celiac disease?
increased gastrin release
A meal high in protein will cause __________.
across the apical membrane of enterocytes
A molecule of glucose being absorbed in the small intestine will first be transported __________.
Xerostomia would lead to a dramatic increase in Hydrogen ions (H+) that are added to saliva as a means for neutralizing bicarbonate ions that may be regurgitated into the esophagus during eating.
A patient has been taking large doses of diphenhydramine, an over-the-counter antihistamine medication, for a severely pruritic (itchy) skin rash. The medication has caused her to develop a very dry mouth (xerostomia). Which of the following statements inaccurately describes how xerostomia would affect a process associated with saliva?
Gastrin
A patient presents with gastric acid hypersecretion. It can be explained by an increase in the plasma concentration of which of the following?
Pernicious anemia
A patient presents with gastric acid hypersecretion. It can be explained by an increase in the plasma concentration of which of the following?
Pancreatic juice
Acinar cells of the pancreas release:
Normally, the duodenum lacks a mucosal layer
All of the following reasons can explain why most peptic ulcers, like Mr. Volpe's, occur in duodenum EXCEPT which statement? -normally, the duodenum lacks a mucosal layer -the chyme coming from the stomach is very acidic -the duodenum is the anatomical structure nearest to the stomach's outlet
secretin
An increase in HCl (hydrochloric acid) arriving in the duodenum would stimulate which hormone that would help to counteract the effects of HCl?
descending colon
At the splenic flexure, the colon becomes the:
brush border enzymes
Before carbohydrates are absorbed, __________ digest disaccharides into monosaccharides
mouth
Carbohydrate digestion begins in the
It is the primary site of chemical digestion and absorption of nutrients
Celiac disease affects the small intestine. The immune system attacks the gluten protein found in wheat, rye and barely, and also damages the lining of the small intestine. What is the primary function of the small intestine?
Loss of the villi surface area and a decrease in absorption of nutrients, causing malabsorption
Celiac disease can also cause more significant issues in the digestive system. Based on your knowledge of the function of the small intestine, which of the following do you think may occur as a result of the resulting inflammation and damage to the lining of the small intestine? -A decrease in the ability of the brush border cells to produce enzymes, and a decrease in chemical digestion. -An increase in the production of mucous resulting in a decrease in absorption of nutrients. -Loss of the villi surface area and a decrease in absorption of nutrients, causing malabsorption. -Interference with the ability of the pancreas to secrete digestive enzymes and hormones.
Trypsinogen is converted to active trypsin.
Celiac disease disrupts the absorption of all of the macronutrients, which include lipids, carbohydrates, and proteins. Which of the following events is NOT associated with lipid absorption in the small intestine? -Trypsinogen is converted to active trypsin. -Micelle formation. -Pancreatic lipase activity. -Chylomicron formation.
lactase
Cherise is lactose-intolerant because she produces insufficient amounts of an enzyme called:
True
Cholecystokinin (CCK) and secretin are produced by the duodenum to target the acinar cells of the pancreas. T/F
Presence of food in the stomach distends the stomach wall and stimulates acetylcholine release, increasing acid secretion
Chronic gastritis affects the normal function of the cells found in the gastric pits. Which of the following events revolving around hydrogen ion secretion is NOT associated with the cephalic phase of digestion? -Presence of food in the stomach distends the stomach wall and stimulates acetylcholine release, increasing acid secretion. -The sight of food triggers the vagus nerves to release acetylcholine onto parietal cells, which directly stimulates them to release hydrogen ions. -The smell of food triggers vagal nerve stimulation, which leads to the release of gastrin, which leads to an increase in hydrogen ion secretion. -The thought of food increases activity in the vagus nerve, which stimulates the release of histamine
Secretion of bicarbonate-rich mucosal mucus and pancreatic juice in the duodenum.
Dr. Lorraine explains to Mr. Volpe that H. pylori decreases the buffering effect in his duodenum. How does the duodenum buffer the acidic gastric chyme?
Somatostatin
Dr. Lorraine explains to Mr. Volpe that the H. pylori often causes excess stomach acid secretion. All of the following mechanisms normally increase gastric acid secretion EXCEPT ________. -somatostatin -histamine -gastrin
To provide a protective barrier
Dr. Lorraine is suspicious of a peptic ulcer, which is a disruption in the stomach or duodenal mucosa extending through its muscularis layer. The primary function of the mucosa is _________.
The epiglottis closes the glottis
During the swallowing reflex __________. -The tongue closes the pharynx -The epiglottis closes the glottis -the esophageal sphincter closes the esophagus
intestinal phase
During which phase in the control of the digestive system would bicarbonate and bile be stimulated?
bile salts
Emulsification requires:
VIP (vasoactive intestinal peptide)
Enteric interneurons that are inhibitory to smooth muscle use which of the following neurotransmitters?
1. mucosa 4. submucosa 2. muscularis externa 3. serosa (adventitia)
From deep (innermost) to superficial (outermost), the layers of the organs of the alimentary canal are: 1. mucosa 2. muscularis externa 3. serosa (adventitia) 4. submucosa
true
From large to small, the types of folds associated with the small intestine are circular folds, villi, and microvilli. t/f
cystic duct
Gallstones may block the flow of bile from the gallbladder by becoming lodged in the
true
Gastrin increases hydrogen ion secretion by the stomach. t/f
chief
HCl secretions convert pepsinogen to the active hormone pepsin. What cells in the gastric pits produce pepsinogen?
manufacture and export a variety of proteins
Hepatocytes contain an extensive rough endoplasmic reticulum, Golgi apparatus, and abundant exocytotic vesicles. These cellular structures work together to ______.
gastrin
Hormone produced by an enteroendocrine cell of the stomach called a G cell
somatostatin
Hormone produced by an enteroendocrine cell of the stomach to inhibit acid secretion by the stomach
gastric-inhibitory peptide (GIP)
Hormone produced by the duodenum to reduce acid secretion by the stomach
secretin
Hormone released by the duodenum in response to acids and lipids in the duodenum
cholecystokinin (CCK)
Hormone released by the duodenum in response to lipids and partially digested proteins in the duodenum
the jejunum
In celiac disease, gluten found in wheat products triggers an inflammatory response in the mucosal lining of the small intestine, disrupting the structure and function of villi. Loss of villi would be expected to have the greatest impact on nutrient absorption in which division of the small intestine?
acinar cells
In response to a steak dinner, certain secretions are needed to aid digestion. What cells in the pancreas would provide these secretions?
duodenum
In which organ is chyme mixed with pancreatic juice and bile?
pancreas
Inactive precursors to enzymes are released by this organ to catalyze reactions that digest proteins in the small intestine
mucosa
Jerry had an ulcer affecting the innermost epithelium of the stomach facing the lumen. Which layer of the alimentary canal was ulcerated?
false
Julie smelled cake baking in the oven, triggering the gastric phase of stomach regulation. t/f
amino acids can be metabolized for energy
Liver transaminases (leaked into the blood from damaged liver cells) remove amine groups from amino acids so that ______.
deglutition
Mary's stroke left her unable to swallow. What specialized type of propulsion was affected?
hydrolysis
Most digestive enzymes catalyze __________ reactions.
small intestine
Most nutrient absorption in the GI tract occurs in the __________.
sympathetic postganglionic fibers
Norepinephrine is the neurotransmitter released by which fibers?
mass movements
Peristaltic contractions that propel the contents of the colon toward the distal large intestine are:
Any event that increases large intestine motility does not allow enough time to absorb excess water from fecal material.
Persistent diarrhea is a common complaint of both celiac disease and Crohn's disease. Which of the following statements best describes how large intestine motility and diarrhea are related?
parietal cells
Proton-pump inhibitors are drugs that block the secretion of gastric acids. Which cells are affected by these drugs?
saliva
Rolita had the mumps as a child and experienced swelling in the parotid glands. What do these glands secrete?
fear
Salivation is controlled almost entirely by the nervous system. Which of the following stimuli would inhibit salivation? fear nausea the thought of food a lemon
proteins
Since her stomach was removed, Mrs. Lopez has the most difficulty initiating digestion of:
increased risk of dental cavities, or caries
Sjögren's syndrome is an autoimmune disorder in which the body's white blood cells attack and destroy exocrine glands, specifically the salivary glands. What could a patient with this syndrome expect?
parietal
The __________ cells of the stomach produce and secrete hydrochloric acid (HCl).
peristalsis
The bolus is able to move down the esophagus even if you are upside-down, because of __________.
an acidic pH
The conversion of pepsinogen into the active form, pepsin, requires:
proteins
The digestion of which food group may be affected by an inadequate amount of stomach acid?
mouth
The enzyme salivary amylase catalyzes the reactions that break polysaccharides into oligosaccharides in this organ
cardia
The esophagus empties into the __________ region of the stomach
right and left lobes of the liver
The falciform ligament separates the
defacation
The final process to occur in the alimentary canal is:
cecum
The first portion of the large intestine is the:
upper esophageal sphincter
The first sphincter encountered in the alimentary canal is the
perforate bacterial plasma membranes
The function of lysozyme in saliva is to __________.
liver
The gallbladder is located on the posterior side of the
cystic duct
The gallbladder releases bile into the __________.
liver
The hepatic portal vein takes the breakdown products of nucleic acids to this organ for metabolism
true
The internal anal sphincter is controlled involuntarily while the external anal sphincter is controlled voluntarily. t/f
circular folds (plicae circulares)
The largest folds in the small intestine are the __________.
false
The mucosa of the alimentary canal from esophagus to anus is composed of simple columnar epithelium. t/f
duodenum
The pancreatic juices transported in the main pancreatic duct are destined for the
bile storage
The removal of the gallbladder will affect
bicarbonate- and potassium-rich mucus
The secretion in the large intestine consists of which of the following? -intrinsic factor -digestive enzymes such as CCK and secretin -bile -bicarbonate- and potassium-rich mucus
cephalic
The smell of croissants in a bakery would trigger the __________ phase of gastric secretion
true
The stomach differs anatomically from other organs of the alimentary canal because it has an additional oblique layer of muscularis externa for churning. t/f
true
The teeth are involved in mechanical digestion as they are the major organs of mastication. t/f
false
The terminal portion of the large intestine is the rectum. t/f
a gluten-free diet
There are methods of treating and living with celiac disease. Select the treatment method that you think would be most beneficial. -A high-protein diet -Anti-inflammatory medication -A low-dairy diet -A gluten-free diet
protein
Transaminases, coagulation factors, and albumin are all what kind of organic compound? carbohydrate protein nucleic acid lipid
nutrient breakdown
What best exemplifies enzymatic hydrolysis?
relaxation of the external anal sphincter
What can we consciously control about the defecation reflex?
pyloric sphincter
What controls the passage of chyme from the last region of the stomach to the duodenum region of the small intestine?
longitudinal layer of the muscularis externa
What creates the taeniae coli?
salivary amylase
What enzyme catalyzes reactions that initiate carbohydrate digestion?
inhibit the immune system
What is NOT a major function of the normal flora of the large intestine?
Gastrin
What is released by the enteroendocrine cells of the gastric glands? -gastrin -pepsinogen -intrinsic factor
Bile
What is responsible for the emulsification of lipids in the duodenum?
ileum
What is the final segment of the small intestine?
propulsion
What is the main job of the pharynx?
bile salt re-entry into the liver
What is the most potent stimulus for bile production and the release of bile by the liver?
gallbladder
What other organ in Mrs. Fender's right upper quadrant, besides the liver, must be considered when investigating her abdominal pain?
ileocecal valve
What prevents bacteria and materials in the large intestine from flowing backward into the ileum of the small intestine?
lower third of the esophagus
What region of the esophagus is composed of smooth muscle only?
cardia
What region of the stomach does food first enters after its passage through the relaxed gastroesophageal sphincter?
hard palate and soft palate
What separates the oral cavity from the nasal cavity?
the stretch of the rectum
What stimulus initiates the defecation reflex?
parietal cells
Which cells release hydrochloric acid (HCl) into the stomach?
vagus nerve
Which cranial nerve stimulates acid secretion during the stomach's gastric phase?
Lactase
Which enzyme catalyzes the reaction of lactose into glucose and galactose? -lipase -maltase -lactase
manufacturing and secreting insulin
Which function below is NOT carried out by the liver? producing bile as a result of blood detoxification storing glucose as glycogen manufacturing and secreting insulin transaminating and deaminating amino acids
gastrin
Which hormone increases acid secretion by the stomach?
cholecystokinin (CCK)
Which hormone stimulates the acinar cells of the pancreas to secrete digestive enzymes?
Ingestion
Which is the first process to occur in digestion?
microvilli
Which modification of the small intestine creates a brush border appearance upon microscopic examination?
secretin
Which of the following GI hormones promotes a pancreatic juice rich in bicarbonate ions?
Accessory pancreatic duct
Which of the following does NOT transport bile? -cystic duct -common hepatic duct -accessory pancreatic duct
Rugae
Which of the following does not increase surface area in the small intestine? Villi Rugae Mucrovilli
pepsin
Which of the following enzymes digests proteins? nucleases salivary amylase pepsin pancreatic lipase
secretin
Which of the following hormones stimulates pancreatic secretions? motilin histamine secretin gastrin
CCK (cholecystokinin)
Which of the following intestinal hormones stimulates the release of bile from the gall bladder?
Manufacturing blood cells
Which of the following is NOT a major job of the digestive system? -fluid and electrolyte homeostasis -manufacturing blood cells -acid-base homeostasis
segmentation
Which of the following is NOT a process occurring in the oral cavity? segmentation ingestion propulsion chemical digestion
Filtration
Which of the following is NOT one of the functions of the digestive system? -filtration -absorption -ingestion
stores and concentrates bile
Which of the following is NOT one of the functions of the liver?
pancreas
Which of the following is NOT part of the gastrointestinal (GI) tract? -pharunx -esophagus -stomach -pancreas
detoxification
Which of the following is a protective function of the liver related to absorption of chemicals found in the body? -Bile excretion. -Detoxification. -Emulsification. -Nutrient metabolism
external anal sphincter
Which of the following is a voluntary sphincter?
esophagus
Which of the following is an organ of the alimentary canal? -spleen -pancreas -esophagus -liver
Pepsin-oligopeptides
Which of the following is paired incorrectly? -Trypsin-oligopeptides -pepsin-oligopeptides -pancreatic-lipase
Appendix
Which of the following organs is NOT a likely culprit since it is not in the epigastric region? -appendix -liver -stomach
Peristalsis involves rhythmic contractions that are not only involved in propulsion, but also aid in mechanical digestion in some segments of the alimentary canal
Which of the following statements about digestive system processes is true? -Absorption is the process in which ingested food and liquids move from one digestive organ to the next. -Ingestion occurs primarily in the stomach and involves enzymatic breakdown of nutrients. -Secretion is the process in which undigested and unusable materials are propelled through the alimentary canal. -Peristalsis involves rhythmic contractions that are not only involved in propulsion, but also aid in mechanical digestion in some segments of the alimentary canal.
vitamin B12
Which of the following vitamins is absorbed in the ileum after binding to intrinsic factor?
large intestine
Which organ functions to absorb significant quantities of water, electrolytes, and vitamins?
absorption
Which process is NOT a main function of the stomach?
segmentation
Which process is a squeezing motion of the circular layer of smooth muscle in the small intestine?
duodenum
Which segment of the small intestine receives chyme from the stomach?
The liver is unable to take up glucose and store it as glycogen
Why does liver dysfunction, such as cirrhosis, lead to hyperglycemia?
A gallstone that blocks the hepatopancreatic ampulla (ampulla of Vater) will block the release of digestive enzymes from the pancreas.
Why might a gallstone affect the pancreas?
pepsinogen
chief cells release
small intestine
lipids are ssembled into trglycerides and packaged into chylomicrons within enterocytes of this organ
absorption is best described as the:
movement of food particles through the wall of the alimentary canal.
stomach
the enzyme pepsin catalyzes reactions that digest proteins in this organ
churning and peristalsis of the stomach
what does the gastric pacemaker regulate
low lipid compostition in chyme entering the duodenum
which of the following encourages gastric emptying -low lipid composition in chyme entering the duodenum -low pH entering the duodenum -high solute concentration in chyme entering the duodenum -high degree of stretch in the duodenum wall