From the outside in, the correct order of the layers of the digestive tract is:
serosa, muscularis externa, submucosa, mucosa.
Waves of smooth muscle contraction that propel materials along the digestive tract are called:
The mesentery that hangs like an apron from the lateral and inferior portion of the stomach is the:
The lingual frenulum:
All of the above:
-connects the tongue to the floor of the oral cavity.
-may need to be cut if the condition of ankyloglossia exists.
-is a thin fold of mucous membrane.
The mucosa and submucosa of the esophagus are folded for:
to allow the expansion of the esophagus during the passage of a large bolus.
Which of the following is a function of the stomach?
both a and b
-Mechanical breakdown of food
-Production of intrinsic factor
When you walk into a Mexican restaurant and smell the savory aroma of fajitas, which phase of gastric activity is triggered?
The duodenum differs from the rest of the small intestine in that its submucosa contains many __________ that secrete mucus.
Concentrated crystals of minerals and salts in the gallbladder produce:
a condition called cholelithiasis
Liver cells, or hepatocytes, receive blood from the:
both a and b.
hepatic portal vein
The defecation reflex:
both a and b.
-involves long and short reflexes.
-involves two positive feedback loops.
The large intestine absorbs which of the following vitamins from colonic bacteria?
All of the above
Vitamin B5, or pantothenic acid
The layer of the digestive tract that contains large blood vessels, lymphatics, and a network of nerve fibers called the plexus of Meissner is the:
Each of the following products of digestion is taken up by capillaries in the small intestine except one. Identify the exception:
Which of the following statements is false concerning the teeth?
Dentin, the material that makes up the enamel of the teeth, is a type of spongy bone, thus giving the tooth its hardness.
A layer of a material called cementum covers the dentin of the root and attaches the tooth to the periodontal ligament.
Which salivary glands produce a thick serous secretion containing large amounts of salivary amylase?
Which type of tooth is conical with a pointed tip and used for tearing and slashing?
Cuspids or canines
During the pharyngeal phase of deglutition:
the larynx elevates and the uvula and soft palate block the nasopharynx.
Which of the following statements is false concerning aging and the digestive system?
Dehydration becomes less common as a result of the body's inability to effectively rid itself of water.
Which of the following statements is false regarding the Kupffer cells of the liver?
Kupffer cells have the ability to produce bile.
Of the 1,500 mL of material that enters the large intestine on a daily basis, approximately how much water in the material is reabsorbed?
During the defecation reflex:
parasympathetic centers in the sacral region of the spinal cord stimulate mass movements.
Fatty acids and monoglycerides interact with the bile salts in chyme to form small, lipid-bile salt complexes called:
Treatment for a morbidly obese man includes surgery to reduce the length of his intestine. Which region of the small intestine should be removed to achieve greatest weight loss?
Which of the following digestive regions is responsible for the propulsion of materials into the esophagus?
Which of the following major layers of the digestive tract is described as a layer of dense irregular connective tissue filled with blood vessels and the plexus of Meissner?
Strong contractions of the ascending and transverse colon moving the contents of the colon toward the sigmoid colon are called:
Which of the following salivary glands produce salivary amylase, a carbohydrate-digesting enzyme?
both a and c
Which of the following statements about peritonitis is false?
It leads to inflammation of the digestive mucosa.
The three pairs of salivary glands that secrete into the oral cavity include:
parotid, sublingual, and submandibular
The pharyngeal muscles that push the food bolus towards the esophagus are the:
pharyngeal constrictor muscles
The inferior end of the esophagus normally remains in a state of active contraction that:
prevents the backflow of materials from the stomach into the esophagus
The hormone that promotes the flow of bile and of pancreatic juice containing enzymes is the:
The longitudinal ribbon of smooth muscle visible on the outer surfaces of the colon just beneath the serosa are the:
The vermiform appendix is dominated by what type of lymphatic structures in the mucosa and submucosa?
The vitamins liberated by bacterial action and absorbed in the large intestine are:
biotin, pantothenic acid, and vitamin K
Which of the following organic nutrients are not absorbed by capillaries in the intestinal villi?
The nutrients that can be absorbed without preliminary processing but may involve special transport mechanisms are:
water, electrolytes, and vitamins
The intestinal epithelium absorbs monosaccharides by:
facilitated diffusion and cotransport mechanisms
When two fluids are separated by a selectively permeable membrane, water tends to flow into the solution that has the:
higher concentration of solutes
Many visceral smooth muscle networks show rhythmic cycles of activity in the absence of neural stimulation due to the presence of:
pacesetter cells that spontaneously depolarize and trigger contraction of entire muscular sheets
The reason a completely dry food bolus cannot be swallowed is:
friction with the walls of the esophagus makes peristalsis ineffective
Gastric glands, which produce most of the gastric juice, are abundant in which of the following regions of the stomach?
both b and c
The two factors that play an important part in the movement of chyme from the stomach to the small intestine are:
stomach distension and gastrin release
The plicae of the intestinal mucosa, which bears the intestinal villi, are structural features that provide for:
increased total surface area for absorption
The enteroendocrine cells of the intestinal crypts are responsible for producing the intestinal hormones:
cholecystokinin and secretin
An immediate increase in the rates of glandular secretion and peristaltic activity in all segments of the small intestine are a result of the:
The primary effect of secretin is to cause a(n)
increase in secretion of water and buffers by the pancreas and the liver
How does the mucosa of the rectum compare with that of the colon and cecum:
The colon and cecum are lined with a simple columnar epithelium for absorption, whereas the rectum is lined with stratified squamous epithelium because it is next to an opening to the exterior.
The muscular sphincter that guards the entrance between the ileum and the cecum is the:
Which produces the least number of contractions to force food through the digestive tract on a daily basis?
The average composition of the fecal waste material is:
75% water; 5% bacteria; 20% indigestible materials, inorganic matter, and epithelial remains
The two positive feedback loops involved in the defecation reflex are:
stretch receptors in rectal walls, and the sacral parasympathetic system
The "doorway to the liver" (porta hepatis) is a complex that includes the:
bile duct, hepatic portal vein, and hepatic artery