The digestive system processes food, extracts nutrients, and eliminates the residue.
The enteric nervous system regulates much of the digestive activity, but its action depends on the central nervous system.
Odor, sight, and taste stimulate salivatory nuclei in the cerebral cortex.
Enamel is found in the crown of a tooth, whereas dentin is part of both the crown and the root.
Both chemical and mechanical digestion start in the mouth and continue in the stomach.
Gastric juice consists entirely of water and hydrochloric acid.
Absorption of many nutrients starts in the stomach.
The liver is the body's largest gland.
Both pancreatic juice and bile are secreted into the duodenum.
The small intestine begins with the duodenum, which is its longest segment.
The brush borders of intestinal absorptive cells contain numerous goblet cells.
Most fat is digested by pancreatic lipase.
Chylomicrons are secreted from the basal surface of the absorptive cells and taken into the lacteal in the villus.
The large intestine absorbs water, fats, and salts.
The large intestine is longer than the small intestine.
The physiological process that moves a nutrient from the outside of the body to the inside is called __________.
The serous membranes that suspend the stomach and intestines from the abdominal wall are called __________.
- muscularis mucosae
- muscularis externa
The layer that is responsible for the motility that propels food and residue through the digestive tract is called the __________.
- muscularis externa
- mucosa (mucous membrane)
The outermost layer of the digestive tract, which is composed of a thin layer of areolar tissue and simple squamous epithelium, is called the __________.
- muscularis externa
- mucosa (mucous membrane)
- serosa (mesentery)
Which of the following nutrients must be digested in order to be absorbed?
Which of the following is not an accessory organ of digestion?
- Salivary glands
Each of the following lists some of the tissue layers of the digestive tract. Which one has them in correct order from lumen to external surface?
- Lamina propria, muscularis mucosae, submucosa, muscularis externa, serosa
- Serosa, lamina propria, submucosa, muscularis mucosae, muscularis externa
- Mucosa, submucosa, muscularis mucosae, muscularis externa, lamina propria
- Mucosa, muscularis mucosae, submucosa, muscularis externa, lamina propria
- Mucosa, submucosa, muscularis externa, lamina propria, serosa
The small intestine is suspended from the abdominal wall by the ___________.
- falciform ligament
- greater omentum
- lesser omentum
- esophageal hiatus
An example of chemical digestion is the break down of __________ into __________.
- proteins; nucleotides
- amino acids; proteins
- polysaccharides; amino acids
- nucleic acids; nucleotides
- fatty acids; cholesterol
The __________ regulates digestive tract motility, secretion, and blood flow. Its neurons are found in the __________.
- autonomic nervous system; serosa
- central nervous system; muscularis externa and muscularis mucosae
- enteric nervous system; submucosa and muscularis externa
- visceral sensory division; muscularis externa and submucosa
- visceral motor division; mucosa and submucosa
The surface of the tongue is covered with __________ stratified squamous epithelium, and has bumps called __________, where many taste buds can be found.
- keratinized; lingual papillae
- keratinized; lingual frenulum
- nonkeratinized; lingual papillae
- nonkeratinized; tonsils
- nonkeratinized; vallate papillae
Infants have __________ deciduous teeth, whereas adults have __________ permanent teeth.
- 20; 32
- 16; 20
- 28; 20
- 32; 20
- 32; 32
Which of the following is the correct list of tooth anatomy from the most superficial to the deepest?
- Cementum, root canal, enamel
- Enamel, root canal, dentin
- Dentin, enamel, cementum
- Enamel, dentin, pulp
- Crown, enamel, dentin
Which of the following is not normally found in saliva?
The __________ gland is an extrinsic salivary gland, whereas the __________ gland is an intrinsic salivary gland.
- lingual; labial
- submandibular; lingual
- submandibular; sublingual
- sublingual; parotid
- lingual; sublingual
The swallowing center is located in the __________.
- medulla oblongata
- enteric nervous system
The oral phase of swallowing is under __________ control and the pharyngo-esophageal phase is __________.
- central nervous system; also controlled by the central nervous system
- central nervous system; controlled by autonomic reflexes
- autonomic nervous system; controlled by autonomic reflexes
- voluntary; also voluntary
- involuntary; also involuntary
Acid reflux into the esophagus ("heartburn") is normally prevented by __________.
- pharyngeal constrictors
- the upper esophageal sphincter
- the lower esophageal sphincter (LES)
- esophageal glands
- pharyngeal and buccal sphincters
The __________ regulates the flow of contents from the stomach to the duodenum.
- gastric rugae
- pyloric sphincter
- fundic region
- cardiac region
Hydrochloric acid (HCl) is secreted by __________ cells.
- regenerative (stem)
Necessary for Vitamin B12 absorption, __________ is/are secreted by __________ cells.
- intrinsic factor; parietal
- bile salts; chief
- lecithin; hepatic
- hydrochloric acid; parietal
- enterokinase; mucous
Pepsinogen is produced by __________ and is activated by __________, which is secreted by __________.
- chief cells; carbonic anhydrase (CAH); parietal cells
- chief cells; hydrochloric acid (HCl); parietal cells
- parietal cells; hydrochloric acid (HCl); chief cells
- parietal cells; carbonic anhydrase (CAH); chief cells
- enteroendocrine cells; carbonic anhydrase (CAH); parietal cells
Several digestive enzymes are secreted as zymogens because __________.
- it saves one step in their synthesis
- gastric cells do not have the necessary enzymes for their synthesis
- they start digesting intracellular proteins of the gastric cells more quickly
- they act only in the stomach lumen and do not digest intracellular proteins
- they can start digesting dietary proteins more quickly
The enterogastric reflex serves to __________.
- relax the stomach in preparation for swallowed food
- stimulate acid and enzyme secretion when food enters the stomach
- stimulate intestinal motility when there is food in the stomach
- inhibit gastric motility when there is chyme in the small intestine
- relax the ileocecal valve when chyme is on its way to the colon
__________ is a hormone, whereas __________ is an enzyme.
- Enterokinase; pepsin
- Gastrin; secretin
- Gastrin; cholecystokinin (CCK)
- Gastric lipase; histamine
- Secretin; pepsin
The __________ phase is associated with food stretching the stomach and activating myenteric and vagovagal reflexes, which in turn stimulate gastric secretions.
The __________ stores excess glucose and releases it into the blood when needed.
- small intestine
A hepatic triad consists of __________.
- the right, left, and common hepatic ducts
- the common hepatic duct, cystic duct, and bile duct
- the hepatic portal vein and two hepatic ducts
- a bile ductule, a branch of the hepatic artery, and a branch of the hepatic portal vein
- a central vein, a hepatic lobule, and a hepatic sinusoid
Of the following components of bile, only __________ has/have a digestive function.
- bile salts
- neutral fats
The __________ synthesizes bile acids by metabolizing __________.
- duodenum; neutral fats
- ileum; bilirubin
- gallbladder; cholesterol
- pancreas; bile salts
- liver; cholesterol
Pancreatic enzymes are secreted in response to a hormone called __________.
- cholecystokinin (CCK)
Which of the following is not a component of the pancreatic juice?
- Sodium bicarbonate
Which of the following nutrients is absorbed by the lacteals of the small intestine?
- Amino acids
- Water-soluble vitamins
Which of the following enzymes functions at the lowest pH?
- Salivary amylase
- Pancreatic amylase
Contact digestion takes place in/at the __________.
- gastric pits
- surface of the gastric mucosa
- intestinal crypts
- brush border of the small intestine
- cytoplasm in the cells of the small intestine
Which of the following is not associated with the large absorptive surface of the small intestine?
- Circular folds (plicae circulares)
- Intestinal length
Which of the following statements regarding the migrating motor complex is true?
- It milks the chyme toward the colon.
- It allows a bolus to move down the esophagus.
- It churns and mixes residue in the descending colon.
- It churns and mixes a bolus with gastric juices.
- It propels pancreatic juice down the pancreatic duct.
The __________ of the small intestine is/are similar to the __________ of the stomach.
- villi; pyloric glands
- rugae; Peyer patches
- intestinal crypts; gastric pits
- goblet cells; parietal cells
- pyloric sphincter; ileocecal valve
Carbohydrate digestion begins in the __________, whereas protein digestion begins in the __________.
- liver; small intestine
- small intestine; stomach
- mouth; stomach
- mouth; small intestine
- stomach; small intestine
The enzyme(s) called __________ break(s) down the substrate called __________.
- lactase; glucose
- peptidases; proteins
- lipases; micelles
- lactose; lactase
- nucleases; nucleotides
Which of the following statements is true regarding the sodium-glucose transport protein (SGLP)?
- It is a uniport carrier.
- It is an antiport carrier.
- It uses solvent drag to transport glucose and sodium.
- It transports glucose and sodium from the intestinal lumen into the epithelial cells.
- It transports glucose from the intestinal lumen into the epithelial cells, and sodium in the opposite direction.
Amino acids and monosaccharides are absorbed in the __________, and fatty acids are absorbed in the __________.
- small intestine; large intestine
- small intestine; liver
- stomach; small intestine
- stomach; large intestine
- small intestine; small intestine
Lecithin prepares fats for hydrolysis by forming __________.
- triglycerides, fatty acids, and glycerol
- low density lipoproteins (LDL)
- emulsification droplets
Which of the following is the proper sequence by which proteins are digested by different enzymes?
- Pepsin, trypsin, carboxypeptidase, dipeptidase
- Pepsin, trypsin, dipeptidase, carboxypeptidase
- Trypsin, pepsin, carboxypeptidase, dipeptidase
- Trypsin, pepsin, dipeptidase, carboxypeptidase
- Dipeptidase, carboxypeptidase, pepsin, trypsin
Lipids are transported to the surface of the intestinal absorptive cells by __________, and are then processed into __________.
- fat droplets; micelles
- fat droplets; chylomicrons
- micelles; fat globules
- micelles; chylomicrons
- fat globules; micelles
The three most abundant classes of nutrients are __________.
- carbohydrates, proteins, and minerals
- fats, proteins, and carbohydrates
- proteins, nucleic acids, and carbohydrates
- triglycerides, starches, and proteins
- proteins, fats, and minerals
The muscle tone of the __________ along the colon contracts it lengthwise, causing its walls to bulge and form pouches called __________.
- circular folds; ceca
- taeniae coli; haustra
- haustra; taeniae coli
- internal sphincters; omental (epiploic) appendages
- internal sphincters; ceca
Which of the following is not a process carried out by bacterial flora?
- Digestion of most of the proteins we get in the diet
- Synthesis of vitamin K
- Production of some of the gases found in flatus
- Digestion of cellulose
- Formation of part of the feces
Bacteria constitute about __________% of the dry weight of the feces.
Defecation is stimulated by __________.
- the chemical composition of the feces
- bacterial flora in the feces
- water content of the feces
- lipid content in the feces
- stretching of the rectum
The enzyme that catalyzes the first step reaction in HCl production by gastric parietal cells is called __________.
- carbonic acid
- carbonic anhydrase
Which of the following is not a function of gastric hydrochloric acid (HCl)?
- Activate pepsinogen to pepsin
- Activate lingual lipase
- Emulsify lipids
- Destroy ingested pathogens
- Convert Fe3+ to Fe2+
Which of the following is true regarding the difference between the mucosa of the small and large intestines?
- They both have villi, but only the small intestine has microvilli.
- The small intestine has deeper intestinal crypts than the large intestine.
- The small intestine has simple columnar epithelium and the large intestine does not.
- Intestinal crypts are only found in the large intestine.
- The large intestine has larger circular folds than the small intestine.
Which of the following is not a trigger for mass movements of the colon?
- The gastrocolic reflex
- The duodenocolic reflex
- Chyme filling the duodenum
- Chyme filling the stomach
- The colorectal reflex
The movement of colonic contents from one puckered section to another is called __________.
- the gastrocolic reflex
- the duodenocolic reflex
- mass movement
- haustral contraction