The chemical breakdown of food into small organic fragments that can be absorbed by the digestive epithelium is __________.
Which layer of the digestive tract is responsible for peristalsis and segmentation?
In the oral cavity, the digestive enzyme _________ is found in saliva and begins the digestion of _________.
Which oral structure(s) is (are) responsible for manipulating food to assist in chewing and in the production of the enzyme lipase?
Which type of tooth is responsible for clipping and cutting?
Which regions of the pharynx serve as passageways for food on its way to the esophagus?
oropharynx and laryngopharynx
Which of the following is the term for swallowing?
The lowest portion of the stomach, which forms the sharp curve of the J shape of the stomach, is the __________.
Which of the following phases of gastric activity is caused by the sight, taste, or thought of food?
Which of the following is NOT produced by the gastric glands in the stomach of an adult?
Which of the following is NOT a region of the small intestine?
A series of transverse folds in the small intestine that serve to increase the surface area for absorption are the __________.
What is the function of bile?
to emulsify lipids
The pancreas produces digestive enzymes that digest __________.
carbohydrates, lipids, proteins, and nucleic acids
A small, slender structure that is attached to the large intestine and is dominated by lymphoid nodules is the __________.
The reflex that occurs in the large intestine and promotes the movement of feces toward the anus is the __________.
Which of the following are NOT absorbed in the large intestine?
The large intestine absorbs water, some vitamins, and some organic wastes.
Which of the following does NOT digest a carbohydrate?
Which of the following does NOT digest a protein?
Which of the following is NOT an effect of advancing age on the digestive system?
stronger peristaltic contractions, resulting in diarrhea
Mastication of food
Carries solid foods and liquids to the stomach
Bulk storage of ingested food, chemical and mechanical breakdown of ingested food, and production of the intrinsic factor
Digestion and absorption of nutrients
Reabsorption of water, absorption of important vitamins, and storage of fecal matter
Temporary storage of fecal matter
This stimulates of increased motility in the stomach and the production of acids and enzymes.
Secreted when fats and especially glucose enters the intestine, this enzyme triggers the release of insulin at the pancreas.
Gastric inhibitory peptide
This is secreted when chyme is rich in lipids and partially digested proteins. It triggers the opening of the hepatopancreatic sphincter.
This is released when chyme enters the small intestine and it stimulates mucin production.
Proteins to short-chain polypeptides
Dipeptides and tripeptides to amino acids
trypsinogen to trypsin
A disaccharide to monosaccharides
Put the structures involved in bile transport in the proper order, from the liver to the gallbladder and on to the small intestine
Right and left hepatic ducts
Common hepatic duct
Common bile duct
T/F The pharynx belongs to both the respiratory and digestive systems.
T/F Cuspids are cutting or clipping teeth.
F Incisors are cutting or clipping teeth.
T/F A drop in the pH of the chyme coming from the stomach triggers the release of CCK.
F CCK is a hormone released when chyme is full of fatty acids and triglycerides.
T/F The haustra are formed by contraction of the taenia coli.
T/F The region of the tooth between the crown and the root is called the gingival space.
The muscularis externa propels materials from one portion of the digestive tract to the other by a series of wavelike contractions called peristalsis, while in most areas of the small intestine __________ movements churn and fragment digestive materials.
Pancreatic juice is secreted by units known as pancreatic __________.
__________ are proteolytic enzymes that break small peptide chains into amino acids.
The transverse folds that make up the intestinal lining and provide more surface area for absorption are called __________.
The glycoprotein __________, necessary for vitamin B12 absorption, is produced in the stomach.
True or false? Bile is produced by the gallbladder.
True or False? Once food is digested in the stomach, it is called chyme.
A chylomicron is an example of a digested protein.
Which substance is absorbed through the intestinal lining?
What is the term for breaking down lipids?
Which accessory organ produces amylases, lipases, buffers, and hormones?
Most of the fat absorption occurs in which part of the small intestine?
Where does the process of chemical digestion start?
In the mouth
Enzymes and buffers are considered part of which type of digestion?
chemical. Mechanical digestion involves mixing, churning, and chewing.
What do we call movement of food without direction in the digestive tract?
segmentation. Peristalsis is the movement of food forward through the digestive tract.
Where does major absorption of food substances occur?
the small intestine. Almost all absorption occurs in the small intestine.
Which type of enzyme digests carbohydrates?
amylase. Peptidase breaks down proteins.
Which side of the epithelial cells lining the digestive tract faces in towards the lumen?
apical. The basal surface fuses the cells to the deep tissues.
What is the term for emulsified, digested lipids?
micelles. Chylomicrons are cholesterol-fat complexes that have a protein coating.
Which portion of the small intestine serves as a mixing bowl for substances from the pancreas, liver, and stomach?
the duodenum. As the food enters the small intestines, enzymes, buffers, and bile also enter at the duodenum
In which part of your digestive system is most of the water reabsorbed?
the small intestine. Up to ninety-five percent of the water entering the digestive tract is absorbed here.
Place the following layers of the general GI tract in order from outermost to innermost
Which of the following is NOT part of the digestive tract?
Which of the following is NOT an accessory organ?
function of the digestive tract
There are __________ major layers of the digestive tract.
From the outside in, the correct order of the layers of the digestive tract is
serosa, muscularis externa, submucosa, mucosa.
The inner lining of the digestive tract is the
The movements of the muscularis externa are coordinated by the
Waves of smooth muscle contraction that propel materials along the digestive tract are called
The __________ cells coordinate rhythmic waves of smooth muscle contraction along the digestive tract.
Your digestive tract produces __________ hormones.
18 or more
The visceral peritoneum
covers organs in the peritoneal cavity.
attach organs to the peritoneal wall.
are the spaces between the oral cavity and oropharynx.
The floor of the mouth inferior to the tongue receives support from the __________ muscle.
There are __________ pairs of salivary glands opening into the oral cavity.
Muscles of the tongue are controlled by the __________ nerve.
The attachment of teeth to the alveolus is called a
The outer layer of a tooth is called the
Humans have __________ complete dentitions.
Incisors are used for
clipping or cutting.
The large, crushing, grinding teeth found at the back of each dental arch are the
The esophagus is about __________ long.
begins voluntarily, but continues involuntarily.
The esophagus is lined with
nonkeratinized, stratified squamous epithelium.
Deglutition consists of __________ phases.
Which of the following is a function of the stomach?
the mechanical breakdown of food
the production of intrinsic factor
The fundus of the stomach
is superior to the junction of the esophagus and stomach.
The simple columnar epithelia that line the stomach have an average life expectancy of __________ days.
Chief cells secrete
When the stomach is empty, the mucosa is thrown into folds called
Gastric gland cells secrete
Gastric activity can be divided into __________ phases.
The cephalic phase of gastric activity is directed by
The gastric phase lasts
The major hormone secreted during the gastric phase is
The intestinal phase
controls the rate at which chyme enters the intestine.
The last section of the small intestine is the
The first section of the small intestine is the
The human small intestine averages __________ feet in length.
The wall of the small intestine bears a series of folds called the
Each intestinal villus contains a lymphoid capillary called a
The duodenum differs from the rest of the small intestine in that its submucosa contains many __________ that secrete mucus.
The gastroenteric reflex stimulates motility
along the entire length of the small intestine.
has 20-30 lymphoid nodules
is the terminal end of the small intestine
absorbs most nutrients.
inhibits submucosal glands.
The exocrine secretions of the pancreas drain through __________ duct(s).
The pancreatic duct joins the __________ to drain into the duodenum.
common bile duct
Pancreatic islets account for about __________ percent of the mass of the pancreas.
Pancreatic juice is
Pancreatic juice contains
The typical adult liver weighs about
The human liver has __________ lobe(s).
Liver cells, or hepatocytes, receive blood from the
hepatic portal vein.
Each portal area contains a branch of the
hepatic portal vein
Each lobule has __________ portal triads and __________ central vein(s).
Bile is secreted into narrow channels called __________ between adjacent liver cells.
The liver has more than __________ functions.
Which of the following is a function of the liver?
amino acid metabolism
Bile functions in digestion as a(n)
Bile secretion occurs __________, but bile release occurs __________.
continuously, only when CCK is secreted
inhibits gastric secretion and motility
stimulates secretion of the gallbladder
stimulates production of pancreatic enzymes
The regions of the large intestine include the
The cecum is
where the ileum empties into the large intestine
where the appendix attaches
a blunt-ended pouch
The pouches of the colon are called the
The longitudinal ribbons of smooth muscle that run the length of the colon are called the
The muscles of the external anal sphincter are
The defecation reflex
involves long and short reflexes
involves two positive feedback loops
is entirely involuntary
The large intestine absorbs which of the following vitamins from colonic bacteria?
vitamin B5, or pantothenic acid
One of the major functions of the large intestine is the
absorption of water.
Carbohydrates are digested in the
Proteins are digested in the
Nutrients are absorbed in the small intestine by the process of
Fat soluble vitamins move across the intestinal mucosa by
Vitamin B12 is absorbed by
Water-soluble vitamins (excluding B12 ) are absorbed by
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 except one are taken up by capillaries in the small intestine. Identify the exception.
Each of the following is a function of the oral cavity except one. Identify the exception.
initial digestion of protein
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 bolus is compressed against the hard palate and retraction of the tongue forces it into the pharynx.
Which of these is not an important functions of the highly acidic environment of the stomach?
activating most enzymes in ingested food.
Which of the following is not a pancreatic enzyme?
Which of the following is not a function of the liver?
the liver produces lymphocytes and plasma cells.
The right colic flexure marks the end of which segment of the large intestine?
During the defecation reflex
parasympathetic centers in the sacral region of the spinal cord stimulate mass movements.
Each of the following is a brush border enzyme except one. Identify the exception.
Fatty acids and monoglycerides interact with the bile salts in chyme to form small, lipid-bile salt complexes called
Peyer's patches are associated with which region of the intestine?
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 one of the following organs is not a part of the digestive system?
The active process that occurs when materials enter the digestive tract via the mouth is:
Sympathetic stimulation of the muscularis externa promotes:
muscular inhibition and relaxation
The mucous-producing, unicellular glands found in the mucosal epithelium of the stomach and small and large intestine are:
Which of the layers of the digestive tube is (are) most responsible for peristalsis along the esophagus?
circular and longitudinal layers
Strong contractions of the ascending and transverse colon moving the contents of the colon toward the sigmoid colon are called:
Accelerated secretions by the salivary glands, resulting in the production of watery saliva containing abundant enzymes, are promoted by:
The submandibular gland produces saliva, which is:
both mucus and serous
The three pairs of salivary glands that secrete into the oral cavity include:
parotid, sublingual, submandibular
Crushing, mashing, and grinding of food are best accomplished by the action of the:
The three phases of deglutition are:
buccal, pharyngeal, esophageal
On its way to the esophagus, food normally passes through the:
oropharynx and laryngopharynx
The pharyngeal muscles that push the food bolus toward the esophagus are the:
pharyngeal constrictor muscles
Solid food and liquids are carried from the pharyngeal region to the stomach by the:
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 contractions of the stomach are inhibited by:
Which of the following is secreted by the stomach?
The three divisions of the small intestine are:
duodenum, jejunum, ileum
An enzyme not found in pancreatic juice is:
The functions of the gallbladder involve:
contraction and absorption
The hormone that promotes the flow of bile and of pancreatic juice containing enzymes is:
The longitudinal ribbon of smooth muscle visible on the outer surfaces of the colon just beneath the serosa are the:
Material arriving from the ileum first enters an expanded pouch called the:
The vitamins liberated by bacterial action and absorbed in the large intestine are:
biotin, pantothenic acid, vitamin K
The organic nutrients that provide energy for the human body are:
carbohydrates, fats, proteins
The nutrients that can be absorbed without preliminary processing but may involve special transport mechanisms are:
water, electrolytes, vitamins
The enzyme lactase, which digests lactose to glucose and galactose, is synthesized by:
Hydrochloric acid in the stomach functions primarily to:
facilitate lipid digestion
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
An error in swallowing could most likely be detected by the:
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
The parts of the stomach include:
fundus, body, pylorus
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
Most intestinal absorption occurs in the:
proximal half of the jejunum
The primary function(s) of the gastrointestinal juice is (are) to:
moisten the chyme
assist in buffering acids
dissolve digestive enzymes and products of digestion
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
The peptide hormone that causes the release of insulin from the pancreatic islets is:
The two major regions of the large intestine are the:
colon and rectum
The muscular sphincter that guards the entrance between the ileum and the cecum is the:
The contractions that force fecal material into the rectum and produce the urge to defecate are called:
The average composition of the fecal waste material is: