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Chap 21 Digestive System
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List the organs of the digestive tract:


- large intestine
- anus
- mouth
- oral cavity
- teeth
- tongue
- pharynx
- esohague 
- stomach
- small intestine


What are the 4 accessory organs of digestion?


- sallivary gland
- liver
- gallbladder
- pancreas


The lamina propria and mucous epithelium are components of the ____________ layer.


mucosa


The _________ coordinates activity of the muscularis externa.


myenteric plexus


Contraction of the __________ alters the shape of the intestinal lumen and moves epithelial pleats and folds.


muscularis mucosa


The __________ are double sheets of peritoneal membrane that suspend the visceral organs and carry nerves, lymphatics, and blood vessels.


mesenteries


Sensory nerve cells, parasympathetic ganglia, and sympathetic postganglionic fibers can be found in the _________ plexus.


submucosal


Sandwiched between the layer of circular and longitudial muscle in the muscularis externa is the __________________.


myenteric plexus


The _________ layer of the digestive tract has a dense irregular connective tissue that surrounds the muscularis mucosae.


submucosa


The __________ layer of the digestive tract is classified as being either squamous or columnar.


mucosa


Large blood vessels and lymphatics are found in the ________.


submucosa


The layer of loose connective tissue that directly supports the digestive epithelium is the ___________________.


lamina propia


The _________ plexus includes a sensory neural network.


submucosal


The oral mucosa has ______________ epithelium.


stratified squamous


List areas where stratified squamous epithelial lining can be found in the digestive tract.


- oral cavity
- pharynx
- espohagus


A disease that attacks and disables the myenteric plexus would ________ intestinal motility.


decrease


The circumferential folds that encircle the luman of the small intestine are known as _________.


plicae


In the digestive system and urinary systems, rings of smooth muscle, called _______, regulate the movement of materials along internal passageways.


sphincters


The ability to function over a wide range of lengths is called ______.


plasticity


Which type of muscle cells are arranged in sheets or layers, with adjacent muscle cells electrically connected by gap junctions and mechanically connected by dense bodies?


visceral smooth muscle cells


Which cells are innervated in motor units comparable to those of skeletal muscles, but each smooth muscle cell may be connected to more than one motor neuron?


multi-unit smooth muscle cells


Whenever one muscle cell contracts, the stimulus for contraction speads in a wave throughout the layer, which is which muscle cells?


visceral smooth muscle cells


__________________ is loctated in the iris of the eye, where it regulates the diameter of the pupil; along portions of the male tract; within walls of large arteries; and in the arrector pilli muscles of the skin.


mutil-unit smooth muscle tissue


_____________________ is located in the walls of the digestive system, the gallbladder, the urinary nd many other internal organs.


visceral smooth muscle cells


Waves of muscular contractions that propel the contents of the digestive tract are called __________.


peristalsis


The activities of the digestive system are regulated by hormones, _________________ and _______________ neurons, the contents of the digestive tract, and the intrinsic nerve ___________.


parasympathetic; sympathetic; ?


The functions of the digestive system include:


- ingestion
- mechanical processing
- digestion
- secretion
- absorption
-compaction


_________ occurs when food and liquids enter the digestion tract via the mouth.


ingestion


________ occurs to most ingested solids either before they are swallowed or in the proximal portions of the digestive tract.


mechanical processing


_______ is the chemical and enzymatic breakdown of food into small organic molecules that can be aborbed by the digestive epithelium.


digestion


_________ is performed along most of the digestive tract (however, most of the acids, enzymes, and buffers required for digestion are provided by the accessory digestive organs).


secretion


_________ is the movement of organic molecules, electrolytes, vitamins, and water across the digestive epithelium and into interstial fluid of the digestive tract.


absorption


__________ is the progressive dehydration of indigestible material and organic wastes prior to elimination from the body.


compaction


__________ is the compacted material that results from compaction.


feces


__________ is the elimination of feces from the body.


defecation


A structure that helps prevent food from entering the pharynx prematurely is the _________.


uvula


What are the functions of the tongue?


- manipulate materials in mouth
- occasionally be used to bring foods into oral cavity
- speech
- taste
- forming boluses
- moving food for swallowing


_____ pair(s) of salivary glands secrete into the oral cavity.


3


The roof of the oral cavity is formed by the ____ and ____ palate.


hard; soft


The space between the cheeks or lips and the teeth is called the _______.


vestibule


The ridge of the oral mucosa that surrounds the base of a tooth is the ________.


gingivae


Carbohydrate digestion begins in the _________.


mouth


The connection of the anterior portion of the tongue to the underlying epithelium is the ____________.


lingual frenulum


The uvula is located at the posterior margin of the _______________.


soft palate


What are the functions of the oral cavity?


- mechanical processing
- moistening
- mixing with salivary secretions


The dorsal surface of the tongue is covered with _________.


lingual papillae


True or False?

The tongue is composed of muscles.




TRUE


The _____________ attaches the ventral surface of the tongue to the floor of the oral cavity.





The tongue secretes lingual _______.


lipase


The bulk of each tooth consists of a mineralized matrix to that of a bone called ___________.


dentin


The chamber within a tooth that contains blood vessels and nerves is the __________.


pulp cavity


The root of a tooth is covered by ____________.


cementum


The crown of the tooth is covered by __________.


enamal


________ are blade-shaped teeth that function in cutting or clipping.


incisors


__________ are pointed teeth that are adapted for tearing and slashing.


cuspids


__________ are teeth with flattened crowns and prominent ridges that are adapted for crushing and grinding.


bicuspids


_______ are also known as caninies.


cuspids


Functions of the teeth include:


- chew food
- break down food


The first teeth to appear are the _______ teeth.


primary or primary dentition


There are normally a total of ___ primary teeth.


20


The secondary dentition usually comprises ___ teeth.


32


The espohagus has several variations from the standard plan of the gut tube.  These include epithelium of mucosa is stratitied __________, and _____________ may be striated muscle.


squamous; muscularis externa


During deglutition, the soft palate ______, the laryne _____, the epiglottis ________, and the lower esophageal sphincter __________.


evalates; elevates; closes; opens


What are the phases of deglutition?


1. Bucca phase
2. pharngeal phase
3. esophagneal


The ________ phase begins with compression of the bolus against the hard palate; retraction of the tongue then forces the bolus into the oropharynx and assists in the elevation of the soft palate, thereby sealing off the nasopharynx; is strictly voluntary.


bucca


The _________ phase begins when tactile receptors on the palatal arches and uvula are stimulated; In response, motor commands from the swallowing center in the medulla oblongata then direct a coordinated pattern of muscle contraction in the pharyngeal muscles, while the palatal muscles elevate the uvula and soft palate to block the entrance of the nasophaynx.


pharyngeal


The _________ phase of swallowing begins as the contracitons of pharyngeal muscles forces the bolus through the entrance to the espohagus; once in the espohagus, the bolus is pushed townard the stomachby peristaltic waves.


esphageal


Muscles known as the pharyngeal constrictors function in _______.


swallowing (deglutition)


The ________________ supports most of the small intestine and provides stability and limited movement.


mesentery proper


The ___________ provides access for blood vessels entering and leaving the liver?


lessor omentum


The ___________ contains adipose tissue and provides padding for the anterior and lateral portions of the abdomen.


greater omentum


The serous membrane that lines the peritoneal cavity secretes ________ fluid, which decrease friction and lubricates the caviry.  It also prevents irritation.


peritoneal


Approximately __ liters of fluid are secreted and reabsorbed into the peritoneal cavity each day.


7


The double-layer sheets of serous membrane that support the viscera are called ________.


mesenteries


The regions of the stomach are:


- fundus
- cardia
- body
- pylorus


The ________ of the stomach is the portion of the stomach that is superior to the junction btween the stomach and the esphagus; contacts the inferior, posterior suface of the diaphragm.


fundus


The ________ of the stomach is the superior, medial portion of the stomach within 3 cm. of the junction between the stomach and the esophagus; contains abundant mucus glands whose secretions coat the connection with the espohagus and help protect that tube from the acid and enzymes of the stomach.


cardia


The ______ of the stomach is the area of stomach between the fundus and the curve of the J; it is the largest region of the stomach; functions in mixing bowl for ingested food and secretions produced in the stomach.


body


The ______ of the stomach forms the sharp curve of the J; as mixing movements accur during digestion, it frequently changes shape.


pylorus


The _______ of the stomach connects to the esophagus.


cardia


The ___________ is a fatty sheet that hangsl ike an apron over the abdominal viscera.


greater omentum


The portion of the stomach that is superior to the junction between the stomach and the espohagus is the _____________.


fundus


The part of the stomach that functions as a mixing chamber for food and secretions is the _________.


body


The region of the stomach that empties into the duodenum is the ________.


pylorus


A feature of the digestive epithelium that assists expansion of the stomach is the presence of ________.


rugae


The prominent ridges in the lining of the empty stomach are called ________.


rugae


The ________ mechanically digests ingested food.


stomach


After food and gastic juices combine, the gastric contents are referred to as _________.


chyme


Perietal cells secrete _________.


intrinsic factor


Chief cells secrete _________.


pepsinogen



Diagram to learn on page 779


Gastric pits are openings into ____________.


gastric glands


The enzyme pepsin digests _________.


proteins


An enzyme secreted by the gastric mucosa of a newborn that assists in the digestion of milk proteins is __________.


rennin


The lining of the stomach has simple _______ epithelium, is covered by thick alkaline _________, contains gastric pits, and is constantly being replaced.


columnar; mucus layer


Which of the following would be greater?

- the pH of the blood in gastric veins during digestion of a large meal
- the pH of the blood in gastric veins following a 24 hr. fast
- the pH of the blood in the gastric veins could be greater after a meal or after a fast; there is not enough info. to predict
- the pH in the gastric veins is constant because of buffering.


the pH of the blood in gastric veins during digestion of a large meal


A drug that blocks the action of carbonic anhydrase in parietal cells would result in:


a higher pH during gastric digestion


Mary had her stomach mostly removed to try to overcome obesity.  As a result, you would expect Mary to be at risk for vitimin __ deficiency.


B12

(pernicious anemia)


________ carry absorbed fats to lymphatic system.


lacteals


Plicae and intestine villi increase the surface area of the mucosa of the ______________.


small intestine


_____________ are circumferential folds in the mucosa and submucosa of the small intestine.


plicae circulares


List some of the structures that enhance the absorptive effectiveness of the small intestine:





Products of fat digestion are transported initially by ____________.


lacteals


Submucosal glands that secrete mucus are characteristic of the __________ (first part of the small intestine).


duodenum


Duodenal glands are characteristics of the _________ intestine.


small


The villi are most developed in the _______ segment of the small intestine.


jejunum


Aggregated lymphoid nodules are characteristic of the _______ segment of the small intestine.


ileum


The middle segment of the small intestine is the ____________.


jejunum


The portion of the small intestine that attaches to the cecum is the _________.


ileum


The part of the digestive tract that play the primary role in the digestion and absorption of nutrients is the ___________.


jejunum


The _________ has a few pilcae circulares, and the villi are small.


deudenum


The primary function of the _________ is to receive chyme from the stomach and neutralize its acids before they can damage the aborptive surfaces of the small intestine.


deudenum


The __________ has numerous plicae circulares and the villi are abundant and very long.


jejunum


The ______ has few if any plicea circulares, and the villi are relatively stumpy.


ileum


The ________'s submucosa contains aggregated lymphoid nodules.


ileum


G cells of the stomach secrete ________.


gastrin


An intestinal hormone that stimulates mucus secretion by the submucosal duedenal glands and dialation of intestinal capillaries is ______________.


vasoactive intestine peptide (VIP)


The intestinal hormone that stimulates the pancreas to release a watery, bicarbonate-rich fluid is _________


secretin


An intestinal hormone that stimulates contraction of the gallbladder to release bile is ________.


cholecystokinin (CCK)


An intestinal hormone that stimulates the release of insulin from the pancreatic islet cells is _________.


Gastric inhibitory peptide (GIP)


An intestinal hormone that stimulates gastric secretion is _________.


gastrin


The hormone that stimulates secretion and contraction by the stomach is _____________.


gastrin


Cholecystokinin (CCK) stimulates the pancreas to secrete __________.


rich in enzymes


Gastrin secretion in response to elevated luminal pH is an example of _________ stimulation.


local


In response to the hormone cholecystokinin, the pancreas secretes a fluid rich in _______.


enzymes


In response to the hormone secretin, the pancreas secretes a fluid rich in _______ ion.


bicarbonate


In response to the arrival of acid chyme in the duodenum, the blood levels of _______ rise.


secretin


A drug that blocks the action of the hormone cholecystokinin would affect _______ production of the stomach, the composition of _________ secretions, and the delivery of ______ from the gallbladder.


acid; pancreatic; bile


During the cephalic phase of gastric secretion, there is an increased flow of action potentials along the ______ nerve to the stomach.


vagus


The gastric phase of the gastric secretion is triggered by the entry of food into the ________.


stomach


All of the following are true of the intestinal phase of gastric digestion, EXCEPT that it 
A) precedes the gastric phase.
B) functions to control the rate of gastric emptying.
C) involves both neural and endocrine reflexes.
D) helps ensure that the functions of the small intestine proceed with relative efficiency.
E) begins when chyme enters the small intestine.



precedes the gastric phase


The gastroileal reflex moes some chyme to the _________.


colon


The secretion of acid and enzymes by the gastric mucosa is controlled and regulated by the central nervous system, short reflexes coordinated in the _____ wall, and digestive tract hormones.


stomach


Enterogastric reflexes involve the _____ nervous system, _________ gastric motility and scretion.


entric; inhibits


Enterogastic reflexes are triggered by _____ entering the duodenum.


chyme


The ______________ is responsible for dehydration and compaction of indigestible materials.


large intestine


Powerful peristaltic contractions that occur a few times each day in the colon are called ___________.


mass movements


At the left colic flexure, the colon becomes the ________ colon.


decending


At the right colic flexure, the colon becomes the ______ colon.


assending


Approximately the last 15 cm of the digestive tract is the ______.


rectum


________ are expansible pouches of the colon.


haustra


The ______________ are longitudinal bands of smooth muscle along the colon wall.


taenia coli


The sac-like structure that joins the ileum at the ileocecal valve is the _________.


cecum


The worm-like structure attached to the posteromedial surface of the cecum is the __________.


appendix


The ________________ is primarily responsible for water absorption.


large intestine


Movements unique to the large intestine are ______ movements.


mass


Functions of the large intestine include:


- reabsorption of water and compaction of intestinal contents into feces
- absorption of important vitamins liberated by bacterial actions
-the storage of fecal material prior to defecations


The salivary gland that secretes a watery mixure rich in salivary amylaze and buffers is the ____________.


submandibular


Secretions from the salivary glands are mostly ______, they help control ______ populations in the mouth, help lubricate the oral cavity, and contain enzymes for the digestion of ________.


water; bacterial; polysaccharides


The enzyme amylase digests __________ (specific type of carbohydrate)


polysaccharides


The __________ salivary glands covered by the mucous membrane in the floor of the mouth (Bloom's Taxonomy: Knowledge).


sublingual


Which salivary gland produces a serous secretion containing large amounts of salivary amylase?


parotid


The _________ gland empties into the oral cavity at the level of the second upper molar.


parotid


Increased secretion by all the salivary glands results from _________ stimulation.


parasympathetic


A blockage of the ducts from the parotid glands would interfere with _______ digestion in the mouth.


carbohydrate


The enzyme that digests strach into disaccharides and trisaccharides is ____.


amylase


What are important functions of the liver?


pg. 795; over 200 functions known


The human liver is composed of __ lobes.


4


The structure that marks the division between the right and left loves of the liver is the _________ ligament.


falciform


The _______ ligament is a remnant of the fetal umbilical vein.


round


In the center of a live lobule there is a ______ vein.


central


The basic functional unit of the liver is the _________.


liver lobules


________ are arranged within a lobule of the liver into a series of plates converging toward a central vein.


hepatocytes


_________ are components of the portal triad found at the edges of a liver lobule.


bile duct, branch of hepatic portal vein, branch of hepatic artery


Your patient has inflammation of the mucous membrane lining of the stomach.  This is known clinically as _______.





What are the functions of the Kupffer cells of the liver?


- liver macrophages
- engulf pathogens, cell debris, and damaged blood cells


The _______________ is where pancreatic juice and bile enter the duodenum.


duodenal ampulla


The duodenal ampulla receives scretions from the _____________ duct and the ________ duct.


common bile; pancreatic


The fusion of the hepatic duct and the cystic duct forms the _____________ duct.


common bile


The exocrine portion of the pancreas is composed of pancreatic ________ cells.


acinar


The enzymes produced by the pancreas are:


- pancreatic alpha-amylase
- pancreatic lipase
- nucleases
- proteolytic enzymes
- trypsin, chymotrypsin, carboxypeptidase, elastase


The pancreas produces ________-digesting enzymes in the form of proenzymes.


protein


Bile is stored in the _________.


gallbladder


An enzyme that digests proteins into peptides is _________.


trypsin


Blockage of the common hepatic duct would interfere with the digestion of ________.


fats


The ________ is formed by the union of the cystic duct and the common bile duct.


common bile duct


At the hepatic flexure, the colon becomes the __________ colon.


transverse


At the splenic flexure, the colon becomes the _______ colon.


decending


Your patient with liver failure has a firm rounded abdomen due to accumulation of fluid. This is known clinically as ________.


ascites


Match the term with its activity.
1. gallbladder 2. esophagus 3. pancreas
A) stores bile
B) secretes digestive enzymes
C) transports material to stomach


1-A; 2-C; 3-B


Bile salts aid in the digestion of fats by __________ large fat droplets.


emulsifying


Leon has gallstones. His doctor puts him on a diet low in fat. Why?



The gallbladder functions to concentrate and store bile produced by the liver. In this capacity, the gallbladder reabsorbs water from the bile. Since bile salts are produced from cholesterol, these salts will be precipitated as cholesterol-like gallstones if too much water is reabsorbed. Whenever bile is released by the gallbladder in response to the presence of fats in the duodenum, the smooth muscle in the wall of the gallbladder must contract. This generates severe pain if the cystic duct or common bile duct are blocked by kidney stones. To minimize or prevent this pain Leonʹs doctor prescribes a low-fat : less fat in the diet, less contraction of the gallbladder, and less pain.


Imagine eating a soda cracker, which is basically starch, fat, protein, and salt. How would each of these components be digested? Where within the digestive system would they be digested? Are any accessory organs involved?


Digestion begins in the oral cavity. Food triggers saliva from the parotids, rich in amylase, and from the submandibulars, rich in mucus. The tongue and teeth cooperate to mix all together and form a bolus. Digestion of fats and starch begins due to lingual lipase and salivary amylase. Swallowing reflexes send it to the stomach. Acid and pepsin greet the bolus. Peptides form from the wheat proteins due to action of pepsin. It then travels into the small intestine, where pancreatic lipase and amylase complete fat and starch digestion. Pancreatic proteinases and peptidases reduce peptides to amino acids. These are absorbed by cotransport. Maltose from starch is split into glucose molecules, which are absorbed by cotransport. The salt in the cracker is absorbed during cotransport. Fatty acids diffuse into the epithelial cells because of their lipid character.


What local reflexes control the GI tract?


The GI tract has extensive sensory and motor neuron plexuses that communicate along the entire length of the digestive tube. These systems enable simple reflex behavior. Vomiting is a familiar example. Toxins are detected by sensory neurons in the GI tract. They trigger a reflex reverse peristalsis, emptying the stomach and esophagus of the offensive material. The gastroileal reflex is triggered by stomach distension, causing food to move from the ileum into the colon. Similarly, stomach stretch can trigger reflex mass movements that send chyme into the rectum, promoting a sense of urgency. Another is the gastroenteric reflex, also initiated by stretch receptors in the stomach, that stimulates motility and secretion along the entire small intestine. Finally, the enterogastric reflex causes the emptying and other movements of the stomach to pause for a few moments when gastric contents contact the duodenal mucosa. This is a good example of local autonomic regulation.


Tony is a chronic alcoholic with cirrhosis of the liver, a condition in which liver cells die and are replaced by connective tissue. Which of the following signs would you expect to observe in Tony?


- increased clotting time 
- jaundice
- portal hypertension and ascites


Tom has hepatitis, an inflammation of the liver. Which of the following symptoms would you expect to observe in Tom?


jaundice


Mary had her stomach mostly removed to try to overcome obesity. As a result you would expect Mary to be at risk for ________.


pernicious anemia


If the pancreatic duct was obstructed, you would expect to see elevated blood levels of __________.


amylase


An obstruction of the common bile duct often results in:


-undigested fat in the feces.
-jaundice




The stomach is able to distend a great deal as it receives food because of all of the following, EXCEPT that 
A) there is a great deal of loose tissue in the form of rugae.
B) the smooth muscle of the stomach is very elastic.
C) the hormone gastrin relaxes stomach smooth muscle.
D) sympathetic stimulation decreases the tonus of the gastric smooth muscle.
E) the gastric smooth muscle is very extensible


the hormone gastrin relaxes stomach smooth muscle.


All of the following are true of the process known as cotransport, EXCEPT that 
A) only neutral compounds such as sugars are transported.
B) more than one molecule or ion is moved through the cell membrane at one time. 
C) ATP is not required by the transport protein.
D) saturation phenomenon can be observed.
E) molecules can be moved against a concentration gradient


only neutral compounds such as sugars are transported.


During deglutition, which of the following phases is NOT present? 
A) voluntary
B) pharyngeal 
C) laryngeal 
D) esophageal
E) None of the above. All are phases in deglutition


laryngeal


If the lingual frenulum is too restrictive, an individual
A) has a condition called ankyloglossia.
B) has difficulty eating. 
C) cannot speak normally. 
D) all of the above
E) A and C only


all of the above


All of the following contain mucous cells in the epithelium, EXCEPT the 
A) stomach.
B) transverse colon. 
C) esophagus.
D) small intestine.
E) large intestine


esophagus


The digestive tract is also referred to as the:


-alimentary canal.
-GI tract


Products of fat digestion are transported initially by _________.


lymphatic vessels


The absorption of some sugars in the small intestine involves _______.


cotransport


Nutrients are absorbed by all of the following, EXCEPT 
A) active transport.
B) diffusion.
C) facilitated diffusion. 
D) cotransport.
E) osmosis.


osmosis


All of the following are true of the intestinal phase of gastric digestion, EXCEPT that it 
A) precedes the gastric phase.
B) functions to control the rate of gastric emptying.
C) involves both neural and endocrine reflexes.
D) helps ensure that the functions of the small intestine proceed with relative efficiency.
E) begins when chyme enters the small intestine


precedes the gastric phase


Each of the following is a function of the liver, EXCEPT 
A) synthesis and secretion of bile.
B) antibody production.
C) synthesis of plasma proteins. 
D) inactivation of toxins.
E) storage of glycogen and iron reserves


antibody production


A viral infection that often involes the parotid glands, which swell noticeably, is the __________.


mumps