Food is contained in the gastrointestinal tract from the time of ingestion until it is completely digested and the waste prepared for elimination.
As food passes through the digestive tract, it becomes less complex and the nutrients are more readily available to the body.
Some of the microbes that often invade other organs of the body are rarely found in the stomach. The reason for this is the presence of HCl.
Kupffer cells are found in the liver and are responsible for removing bacteria and worn-out cells.
The pharyngeal-esophageal phase of swallowing is involuntary and is controlled by the swallowing center in the thalamus and lower pons.
The cell type of the wall of the large intestine, excluding anal cells, is very different from that of the small intestine.
Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells.
The myenteric nerve plexus provides the major nerve supply to the GI tract wall and controls GI motility.
The intrinsic ability of visceral smooth muscle to exhibit the stress-relaxation response is termed plasticity.
The major stimulus for production of intestinal fluid is distention or irritation of the intestinal mucosa by hypertonic or acidic chyme.
Ionic iron is actively transported into the mucosal cells, where it binds to the protein ferritin, a phenomenon called the mucosal iron barrier.
The layer of muscle in the intestine directly in contact with the serosa is the circular layer.
The mucosa is found only in the jejunum because this is the only part of the small intestine in need of mucus.
The mechanical and chemical receptors that control digestive activity are located ________.
A) in the glandular tissue that lines the organ lumen
B) in the walls of the tract organs
C) in the pons and medulla
D) only in the esophagus because this is the only part of the tract that needs to change to accommodate food passage
The function of the hepatic portal circulation is to ________.
A) carry toxins to the venous system for disposal through the urinary tract
B) collect absorbed nutrients for metabolic processing or storage
C) distribute hormones
D) return glucose to the general circulation when blood sugar is low
The chemical and mechanical processes of food breakdown are called ________.
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 ______.
C) chemical digestion
D) mechanical digestion
The sheets of peritoneal membrane that hold the digestive tract in place are called ________.
B) lamina propria
C) serosal lining
D) mucosal lining
From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.
A) muscularis externa, serosa, mucosa, & submucosa
B) serosa, mucosa, submucosa, & muscularis externa
C) submucosa, serosa, muscularis externa, & mucosa
D) mucosa, submucosa, muscularis externa, & serosa
The structure known as the fauces is the ________.
A) submaxillary gland
C) thyroid gland
D) passageway between the oral cavity and the pharynx
The epithelial membrane called the mucosa ____.
A) absorbs mucus, digestive enzymes, and hormones
B) absorbs the end products of digestion into the lymphatic system
C) fights infectious disease
D) contains the lamina propria
The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________.
A) muscularis mucosae
D) lamina propria
The plicae circulares and intestinal villi are found in which of the four layers of the alimentary tube wall?
D) lamina propria
The structures that produce new cells for the mucosa of the small intestine are the ________.
C) intestinal crypts
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?
A) plicae circulares and intestinal villi
B) the vast array of digestive enzymes
C) Brunnerʹs glands
D) the rugae
Select the statement that is true concerning primary teeth.
A) There are 27 primary teeth, and the molars are permanent.
B) There are 24 primary teeth, and no new primary teeth appear after 13 months.
C) There are 20 primary teeth, and by 24 months of age most children have all 20.
D) There are 32 primary teeth, and most children lose these teeth due to decay because they are never very strong.
Which of the following is true concerning the number and type of permanent teeth?
A) There are 32 permanent teeth, and the wisdom teeth are the last to emerge.
B) There are 27 permanent teeth, and the first molars are usually the last to emerge.
C) The number of permanent teeth is always equal to the number of primary teeth.
D) The number of upper permanent teeth is not equal to the number of lower permanent teeth.
Which of the following is not true of saliva?
A) cleanses the mouth
B) contains enzymes that begin the breakdown of proteins
C) moistens food and aids in compacting of the bolus
D) dissolves food chemicals so they can be tasted
The salivary glands are composed of which two types of secretory cells?
A) goblet cells and squamous epithelial cells
B) parietal cells and glial cells
C) serous cells and mucous cells
D) cuboidal epithelium and ciliated columnar cells
The solutes contained in saliva include ________.
A) only salts and minerals
B) only proteases and amylase
C) mucin, lysozyme, electrolytes, salts, and minerals
D) electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA
In addition to storage and mechanical breakdown of food, the stomach ________.
A) initiates protein digestion and denatures proteins
B) is the first site where absorption takes place
C) is the only place where fats are completely digested
D) is the first site where chemical digestion of starch takes place
Hydrochloric acid is secreted by which of the secretory cells of the stomach?
A) chief cells
B) parietal cells
C) serous cells
D) mucous neck cells
Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products?
A) enteroendocrine cells
B) parietal cells
C) zymogenic cells
D) mucous neck cells
There are three phases of gastric secretion. The cephalic phase occurs ________.
A) before food enters the stomach and is triggered by aroma, sight, or thought
B) immediately after food enters the stomach, preparing the small intestine for the influx of a variety of nutrients
C) at the end of a large meal, and the juices secreted are powerful and remain in the GI tract for a long period of time
D) when the meal is excessively high in acids and neutralization is required
Peristaltic waves are ________.
A) segmental regions of the gastrointestinal tract
B) churning movements of the gastrointestinal tract
C) pendular movements of the gastrointestinal tract
D) waves of muscular contractions that propel contents from one point to another
Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of ________.
A) starches and complex carbohydrates
B) protein and peptide fragments
C) simple carbohydrates and alcohols
D) fatty acids
Pepsinogen, a digestive enzyme, is secreted by the ________.
A) chief cells of the stomach
B) parietal cells of the duodenum
C) Brunnerʹs glands
D) goblet cells of the small intestine
You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?
The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ______.
A) portal vein
B) pancreatic acini
C) bile canaliculus
D) hepatopancreatic ampulla
The enzymatic breakdown of any type of food molecule is called ________.
B) active transport
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?
Parietal cells of the stomach produce ________.
C) hydrochloric acid
Hepatocytes do not ________.
A) produce digestive enzymes
B) process nutrients
C) store fat-soluble vitamins
Which of the following is not a phase of gastric secretion?
Chief cells ________.
A) occur in the intestine
B) produce HCl
C) are found in the basal regions of the gastric glands
D) produce mucin
Chemical digestion reduces large complex molecules to simpler compounds by the process of ________.
The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure.
If an incision has to be made in the small intestine to remove an obstruction, the first layer of tissue to be cut is the ________.
C) muscularis externa
The terminal portion of the small intestine is known as the ________.
D) pyloric sphincter
The dental formula for an adult is 2-1-2-3. What does the 1 stand for?
A) incisor tooth
B) molar tooth
C) premolar tooth
D) canine tooth
Digestion of which of the following would be affected the most if the liver were severely damaged?
________ is locally regulated in the blood by the active form of vitamin D, which acts as a cofactor.
Important peritoneal folds do not include the ________.
D) round ligament
The lamina propria is composed of ________.
A) loose connective tissue
B) dense irregular connective tissue
C) dense regular connective tissue
D) reticular connective tissue
________ is/are not important as a stimulus in the gastric phase of gastric secretion.
D) Low acidity
Pancreatic amylase does not get to the small intestine via the ________.
A) accessory pancreatic duct
B) main pancreatic duct
C) cystic duct
D) hepatopancreatic ampulla
The function of the goblet cells is to ________.
A) absorb nutrients from digested food and store them for future use
B) produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion
C) secrete buffers in order to keep the pH of the digestive tract close to neutral
D) provide protection against invading bacteria and other disease-causing organisms that enter the digestive tract in food
Under normal conditions, the gastric mucosa pours out as much as ________.
A) 10 liters of gastric juice per hour
B) 1 pint of gastric juice following each meal
C) 2 to 3 liters of gastric juice per day
D) 6 liters of gastric juice when the meal is unusually heavy in fats
Nervous control of gastric secretion is provided by ________.
A) somatic neurons in the spinal cord
B) the vagus nerve and enteric plexus
C) the rubrospinal tracts
D) the reticulospinal and vestibulospinal tracts
Which of the following are types of papillae on the tongue that contain taste buds?
A) fungiform and circumvallate
B) palatine and circumvallate
C) circumvallate and filiform
D) fungiform, circumvallate, and filiform
Which of the following produce intrinsic factor?
A) parietal cells
B) zymogenic cells
C) mucous neck cells
D) enteroendocrine cells
Which of the following enzymes is specific for proteins?
Surgical cutting of the lingual frenulum would occur in which part of the body?
C) nasal cavity
D) salivary glands
A fluid secreted into the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is ________.
B) pancreatic juice
C) intestinal juice
D) gastric juice
The layer of the digestive tube that contains blood vessels, lymphatic nodes, and a rich supply of elastic fibers is the ________.
C) muscularis externa
Which of the following is not characteristic of the large intestine? It ________.
A) does not contain villi
B) exhibits external muscular bands called teniae coli
C) is longer than the small intestine
D) has haustra
Tooth structure includes ________.
A) the dentin, which is the hardest substance in the body
B) a root covered with enamel
C) a thin periodontal ligament that holds the tooth in place
D) pulp, an avascular connective tissue filling the hollow cavity of the tooth
The propulsion of food down the gastrointestinal tract includes ________.
A) the pharyngeal-esophageal phase, an involuntary process
B) deglutition, which is the elimination of undigested materials
C) the buccal phase, an involuntary phase controlled by swallowing centers in the medulla and pons
D) the gastric phase, activated by distension of the stomach receptors
Select the correct statement about the regulation of gastric secretion.
A) Vagus stimulation of the stomach results in decreased secretion of gastric juice.
B) The presence of food in the stomach prevents hormonal control of gastric secretion.
C) Gastric secretion can be stimulated before food has entered the mouth.
D) Gastric secretion is enhanced by very low pH (below a pH of 2).
Paneth cells ________.
A) are more common in the ileum than in the jejunum
B) are absorptive cells in the small intestine
C) secrete enzymes that kill bacteria
D) are located next to the lacteal in a villus
Select the correct statement about digestive processes.
A) Enterogastrone is a hormone that helps increase gastric motility.
B) Pepsin is an enzyme produced by the stomach for the purpose of starch digestion.
C) Chyme entering the duodenum can decrease gastric motility via the enterogastric reflex.
D) All commonly ingested substances are significantly absorbed by the mucosa of the stomach.
Chemical digestion in the small intestine involves ________.
A) a significant amount of enzyme secretion by the intestinal mucosa
B) cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction
C) secretions from the spleen that contain all enzymes necessary for complete digestion
D) bile salts that help emulsify carbohydrates so that they can be easily digested by enzymatic action
Select the correct statement about absorption.
A) Eighty percent of ingested materials have been absorbed by the end of the large intestine.
B) Carbohydrates diffuse across the villus epithelium and are then actively transported into blood capillaries.
C) If intact proteins are transported across the villus epithelium, an immune response may be generated.
D) Amino acid transport is linked to chloride transport.
Select the correct statement about electrolyte absorption.
A) Chlorine ion absorption is coupled to glucose and amino acid transport.
B) Potassium moves across the epithelium by active transport.
C) If vitamin B is not present, calcium is not absorbed.
D) Iron and calcium are absorbed mostly by the duodenum.
You have just eaten french fries, buttered toast, ice cream, and whole milk. Which of the following glands
would be active in helping you to digest this food?
A) the pancreas
B) the buccal glands
C) the thyroid gland
D) the parotid glands
The ingestion of a meal high in fat content would cause which of the following to occur?
A) Severe indigestion would occur, caused by the lack of sufficient digestive enzymes.
B) This type of food would cause secretion of gastrin to cease, causing digestive upset.
C) Bile would be released from the gallbladder to emulsify the fat in the duodenum.
D) The acid secretions from the stomach would be sufficient to digest this food.
The mucosa of the developing alimentary tube comes from ________.
A baby is admitted to the hospital with a history of projectile vomiting after each feeding. On examination, it is found that the sphincter controlling food passage from the stomach to the duodenum is thickened and does not open readily. Because of the babyʹs loss of gastric juice, his blood probably indicates ________.
Hormones that inhibit gastric secretion include ________.
Which of these is not part of the splanchnic circulation?
A) hepatic portal vein
B) inferior vena cava
C) superior mesenteric artery
D) celiac artery
Which of these is not a component of saliva?
B) a cyanide compound
D) nitric oxide