Which of the following is not a common risk factor for acid reflux disease?
sitting upright after a meal
snacking near bedtime
eating fatty or spicy foods
being overweight or obese
answer
sitting upright after a meal
question
What is the condition called where a proximal portion of the stomach pushes through an opening in the diaphragm, allowing stomach acid to pass into the esophagus?
dyspepsia
dysphagia
hiatal hernia
esophageal varices
answer
hiatal hernia
question
Which major process involves the removal of water from intestinal contents?
mechanical breakdown
absorption
ingestion
defecation
answer
Absorption
(absorption is the passage of digested end products and water from the lumen of the GI tract through the mucosal cells into blood or lymph)
Summary of the actions of each major area of the digestive tract.
question
Where does the process of segmentation occur?
esophagus
stomach
small intestine
anus
answer
Small intestine
Several areas of the digestive tract are capable of peristalsis, which propels food onward, but only the small intestine undergoes segmentation, whose purpose is mixing food with enzymes and bringing it close to intestinal walls.
Summary of the actions of each major area of the digestive tract.
question
How would you classify chewing food?
ingestion
propulsion
mechanical breakdown
digestion
answer
mechanical breakdown
Chewing breaks apart and grinds food and mixes it with saliva.
Summary of the actions of each major area of the digestive tract.
question
Which of the following functions is NOT correctly matched with its description?
propulsion: physical breakdown of ingested food in the GI tract
mechanical breakdown: churning movements in the GI tract
ingestion: intake of food nutrients
absorption; passage of digested nutrients into the blood or lymph
answer
Propulsion is the movement of ingested food through the GI tract.
question
Which organ of the digestive tract is the body's major digestive organ?
stomach
liver
large intestine
small intestine
answer
The small intestine is the major digestive organ because it is the site of the majority of enzymatic digestion and absorption of nutrients.
question
Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium?
serosa
mucosa
muscularis externa
submucosa
answer
mucosa
The mucosa's inner lining is composed of columnar epithelium for most of the alimentary canal. Stratified squamous is used in the esophagus, oral cavity, and anus.
Generalized histological structure and layering of the digestive tract.
question
Which layer of the alimentary canal is responsible for segmentation and peristalsis?
serosa
submucosa
mucosa
muscularis externa
answer
muscularis externa
Contractions of the circular and longitudinal layers of the muscularis externa produce the effects of peristalsis and segmentation. In the stomach, an additional muscle layer adds a twisting action.
Generalized histological structure and layering of the digestive tract.
question
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
answer
submucosa
The submucosa layer contains blood and lymphatic vessels, lymphoid follicles, and the submucosal plexus of nerve fibers.
question
The outermost tissue layer of the alimentary canal is the __________.
submucosa
muscularis
mucosa
serosa
answer
serosa
question
Which layer of the digestive tract controls digestive propulsion?
mucosa
muscularis externa
serosa
submucosa
answer
muscularis externa
The smooth muscles in the muscularis work to make the propulsive movements called peristalsis.
question
Which of the following does NOT describe a basic regulator of digestive control?
conscious neural control
Digestive effectors are smooth muscle and glands.
pH, stretch, and osmolarity are some of the inputs that can initiate digestive responses.
Short reflexes act locally in the GI tract.
answer
conscious neural control
Neural control over the digestive system is through the autonomic nervous system, which does not function under conscious control mechanisms.
question
What muscle forms the labia of the mouth and controls most lip movement, including puckering?
zygomaticus
orbicularis oris
levator labii superioris
buccinator
answer
The orbicularis oris muscle is positioned surrounding the mouth and within the labia. It acts to control the movement of the lips.
Anterior view of the oral cavity with mandible depressed.
question
The palatine tonsils are located between which two structures?
he palatopharyngeal arch and the throat
the palatopharyngeal arch and the palatoglossal arch
the tongue and the floor of the oral cavity
the soft palate and the hard palate
answer
the palatopharygnal arch and the palatoglossal arch
The palatine tonsils are located along the lateral margins of the oral cavity between the palatopharyngeal arch and the palatoglossal arch.
question
The uvula is an extension of the __________.
lingual frenulum
oral vestibule
palatopharyngeal arch
soft palate
answer
soft palate
The uvula extends out from and past the soft palate area of the palatopharyngeal arch.
question
Which of the following inhibits salivation?
ingestion of spicy foods
the sight or smell of food
being stressed or frightened
relaxing after a meal
answer
being stressed or frightened
The sympathetic division of the autonomic nervous system is associated with fight-or-flight responses. Stimulation of the salivary glands by the SNS tends to inhibit flow, as when you are scared or nervous and your mouth "goes dry."
question
How many total permanent teeth should an adult have, assuming none have been lost or removed?
8
16
20
32
answer
32
There are two incisors (2I), one canine (1C), two premolars (2PM) and three molars (3M) for a total of 8 on each side of each jaw. Multiply by 4 for a total of 32 adult teeth.
question
How are wisdom teeth (third molars) classified?
as incisors
as permanent teeth
as milk teeth
as primary teeth
answer
as permanent teeth
The third molars, commonly called the "wisdom teeth," are considered to be permanent teeth. There is no equivalent to them in deciduous teeth.
question
Which teeth are best suited for cutting or nipping off pieces of food in the permanent dentition?
molars
premolars (bicuspids)
incisors
canines
answer
incisors
The location and shape of the incisors make them ideally suited for cutting and nipping food.
question
The deciduous dentition consists of __________ teeth.
10
16
20
32
answer
20
question
Which digestive process does NOT occur in the mouth?
ingestion
mechanical breakdown
segmentation
digestion
answer
Segmentation is the back-and-forth mixing movement of food in the small intestine. The process of chewing and mixing food with saliva in the mouth is known as mastication.
question
Which layer of the stomach contains the gastric pits that secrete mucous, acid, and digestive enzymes?
submucosa
muscularis externa
mucosa
serosa
answer
The mucosa of the stomach contains the epithelial lining and the gastric pits, which extend down into the mucosa but do not penetrate the submucosa.
question
Which of these structures is found in the stomach but nowhere else in the alimentary canal?
mucus-forming cells
a circular muscle layer
a lining of columnar epithelium
an oblique muscle layer
answer
an oblique muscle layer
All areas of the alimentary canal have a circular and a longitudinal layer of muscle. The stomach has an additional oblique layer of muscle for "wringing" itself while processing food.
question
Which area of the stomach adjoins the small intestine?
fundus
pylorus
cardia
body
answer
The pylorus is the lowest part of the stomach. It attaches to and empties food into the small intestine via the pyloric sphincter.
question
Which of the following is NOT a characteristic of the stomach?
The stomach mucosa is folded into rugae.
The stomach has three layers of muscle in the muscularis tunic.
The stomach releases enzymes to digest carbohydrates.
The stomach produces a double-layered coat of alkaline mucus.
answer
The stomach releases enzymes to digest carbohydrates.
question
In the __________ phase of gastric secretion, chyme is moved into the duodenum.
cephalic
gastric phase
reflux
intestinal
answer
The intestinal phase occurs when chyme is moved into the duodenum.
question
What role of the stomach is essential to life?
production of chyme
production of hydrochloric acid
production of VIP
production of intrinsic factor
answer
production of intrinsic factor
Without the production of intrinsic factor, the body would not be able to absorb vitamin B12 in the small intestine. This is the only factor that would cause problems with living.
question
Which of the following constitute a portal triad?
the porta hepatis
a bile duct along with a portal venule and arteriole
three lobules sharing a common central vein
the hepatic artery and two hepatic veins
answer
A bile duct along with a portal venule and arteriole constitute a portal triad. The blood vessels provide blood flow to the lobule and the bile duct drains bile.
question
Which vessel delivers nutrient-rich blood to the liver from the digestive tract?
Histological structure of a liver lobule and blood flow patterns.
hepatic vein
hepatic portal vein
inferior vena cava
central vein
answer
hepatic portal vein
All blood from the digestive organs as well as the spleen is delivered to the liver in the hepatic portal vein before being returned to the general circulation.
question
Which chemical activates the transformation of trypsinogen to trypsin?
carboxypeptidase
amylase
chymotrypsin
enteropeptidase
answer
Enteropeptidase is a protein produced by and bound to the membranes of intestinal cells. Contact with this protein converts trypsinogen to trypsin, the active form of the enzyme.
question
What is a major function of pancreatic juice?
emulsifying fats by breaking them into smaller pieces
acidifying the contents of the small intestine
neutralizing chyme entering the small intestine from the stomach
acidifying the contents of the stomach
answer
neutralizing chyme entering the small intestine from the stomach
Pancreatic juice contains bicarbonate (as baking soda does) that can neutralize the pH of acidic chyme coming from the stomach.
question
What triggers the release of secretin from the small intestine?
Chemical action of proteases in the small intestine.
presence of bile in the small intestine
presence of carbohydrates in the small intestine
the presence of acidic, fatty chyme in the small intestine
presence of cholecystokinin (CCK) in the small intestine
answer
the presence of acidic, fatty chyme in the small intestine
The presence of acidic, fatty chyme in the small intestine causes the release of secretin, which in turn inhibits further entry of stomach contents into the intestine until the fat has been emulsified and the pH raised.
question
Which of the following is NOT a secretion of the pancreas?
bicarbonate
nutrient enzymes
bile
insulin
answer
Bile is secreted by the liver.
question
What structural modification of the small intestine slows the movement of chyme through the lumen?
villi
circular folds
intestinal crypts
microvilli
answer
circular folds
The circular folds of the small intestine help slow the progress of food through the intestine so that it can be digested and absorbed more effectively. These folds also increase surface area and help mix chyme.
question
Which cells in the small intestine's mucosa secrete mucus?
goblet cells
enteroendocrine cells
enterocytes
Paneth cells
answer
goblet cells
Goblet cells, which secrete mucus and are found in several areas of the digestive tract, are located on the villi of the small intestine.
question
The __________ is the first segment of the small intestine.
jejunum
duodenum
ileum
colon
answer
duodenum
question
Which of the following is NOT a structural modification of the small intestine that increases surface area?
villi
rugae
microvilli
circular folds
answer
Rugae are a structural modification that allow expansion of the stomach wall.
question
Which of the following propels food residue over large areas of the colon three to four times a day?
defecation reflex
Valsalva's maneuver
mass movement
haustral contractions
answer
mass movement
Mass movement propels food residue over large areas of the colon three to four times a day. The defecation reflex occurs when the rectal wall stretches as mass movements force feces into it.
question
As wastes navigate the large intestine, which features do they pass through, in order?
the right colic, left colic, and sigmoid flexures
the sigmoid, right colic, and left colic flexures
the sigmoid, left colic, and right colic flexures
the cecum, left colic, and right colic flexures
answer
the right colic, left colic, and sigmoid flexures
question
Which of the following is the primary physiological function of the large intestine?
mechanical breakdown of food
primary digestion of food
nutrient absorption
water absorption and feces elimination
answer
Water absorption and feces elimination are the primary physiological functions of the large intestine. The large intestine also provides a transport route and a surface for healthful bacteria.
question
Which of the following is NOT a function of the large intestine?
absorption of water
production of intrinsic factor
absorption of electrolytes
absorption of vitamins
answer
production of intrinsic factor
Intrinsic factor is produced by the stomach to help vitamin B12 be absorbed before ever reaching the large intestine.
question
Bacteria that reside in the large intestine make vitamin C.
True
False
answer
False
Bacteria that reside in the large intestine make B complex vitamins and vitamin K. Enteric bacteria also form gases such as CO2, methane, H2, and N2 as byproducts of metabolizing nondigested starches such as cellulose.
question
__________ can result if food passes too slowly through the large intestine.
Colitis
Constipation
Diarrhea
Irritable bowel syndrome
answer
Constipation occurs when food moves too slowly through the alimentary canal.
question
Carbohydrates are digested into __________.
monosaccharides
glycerol
nucleotides
amino acids
answer
Monosaccharides are sugars, the building blocks of carbohydrates such as starch or glycogen.
question
Which of the following are NOT correctly matched?
amylase: carbohydrate digestion
protease: lipid digestion
nuclease: DNA and RNA digestion
lipase: fat digestion
