Anatomy- Chapter 23 Digestive System

Which of the following is considered to be an accessory organ of the digestive system?

gallbladder

The major means of propelling food through the digestive tract is __________.

peristalsis

Which major process involves the elimination of indigestible substances from the body via the anus?

defecation

Where does the process of segmentation occur?

small intestine

How would you classify chewing food?

mechanical breakdown

The __________ is the serous membrane that lines the abdominal body wall.

parietal peritoneum

In a patient suffering from untreated infection-induced peritonitis, an infection in the visceral peritoneum immediately ______.

spreads directly to the parietal peritoneum

Which histological layer of the digestive tract is composed primarily of epithelial tissue?

mucosa

The __________ circulation includes all of the major abdominal arteries that serve the digestive organs.

splanchnic

The innermost tissue layer of the alimentary canal is the __________.

mucosa

The nervous system does not regulate digestive activity.

False

Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium?

mucosa

Which layer of the alimentary canal is responsible for segmentation and peristalsis?

muscularis externa

Which layer of the alimentary canal contains the nerve supply of the enteric neurons that regulate digestive system activity?

submucosa

A person with ankyloglossia would likely have difficulty pronouncing the word ______.

All of the listed responses are correct.

A mumps viral infection of the two parotid glands may ______.

spread to the other salivary glands

Hyposalivation can be treated with a drug that ______.

stimulates muscarinic receptors in salivary gland serous cells

Impacted wisdom teeth is a problem that is never observed in children because ______.

they lack third molar teeth

After root canal therapy, a tooth may become infected again due to poor dental hygiene. The patient might not seek treatment for this newly infected tooth because ______.

the tooth lacks a nerve that would make the patient perceive pain

Saliva does NOT __________.

aid in the chemical digestion of proteins

The primary dentition consists of __________ teeth.

20

How many total teeth does the following dental formula indicate?

20

How are wisdom teeth (third molars) classified?

permanent teeth

Which teeth are best suited for cutting or nipping off pieces of food in the permanent dentition?

incisors

What muscle forms the labia of the mouth?

orbicularis oris

What is the function of the soft palate?

The soft palate rises reflexively to close off the nasopharynx when swallowing occurs.

What is the opening to the mouth called?

oral orifice

Which of the following is NOT a function of saliva?

Saliva contains enzymes that begin the chemical breakdown of proteins.

Which of the following inhibits salivation?

sympathetic division of the autonomic nervous system

Gastric juice does not typically cause a burning sensation within the stomach. But reflux of this gastric juice into the esophagus can cause a burning sensation. One reason why this occurs is that the esophagus ______.

secretes mucus that is not identical to stomach mucus

The __________ guards the entry of food into the stomach.

cardiac sphincter

Which digestive process normally occurs only in the mouth?

ingestion

Which of the following is NOT a characteristic of the stomach?

The stomach releases enzymes to digest carbohydrates.

Which of the following components of saliva helps convert food-derived nitrates into nitric oxide (NO)?

bacteria present on the back of the tongue

In a patient suffering from a gastric ulcer caused by Helicobacter pylori, the cells most likely to have been damaged first are the ______.

mucous cells

Before and during vomiting, the emetic center initiates motor responses that involve ______.

All of the listed responses are correct.

What role of the stomach is essential to life?

production of intrinsic factor

In the __________ phase of gastric secretion, chyme is moved into the duodenum.

intestinal

The __________ is the last segment of the small intestine.

ileum

Blood draining from the stomach is more alkaline (basic) than blood that serves the stomach.

True

Which tunic of the stomach is constructed of simple columnar epithelium composed entirely of mucous cells?

mucosa

Which mesentery helps tether the stomach to the liver?

lesser omentum

The mucosa collapses inward when the stomach is empty, forming large folds known as __________.

rugae

Cirrhosis can cause ______.

a bleeding disorder

An obstruction by a gallstone is least likely to occur in the ______.

common hepatic duct

Which organ of the digestive tract is the body’s major digestive organ?

small intestine

What is the major digestive function of the pancreas?

production of digestive enzymes

Which of the following is NOT a structural modification of the small intestine to increase surface area?

rugae

Bile is produced by the __________.

liver

The pancreas secretes __________.

procarboxypeptidase

Most digestion and absorption of nutrients occur in the __________.

small intestine

The liver is able to regenerate even after 50% of its original mass is lost.

True

What structural modification of the small intestine slows the movement of chyme through the lumen?

circular folds

Which cell in the small intestine’s mucosa is a mucus-secreting cell?

goblet cell

Which cells of the small intestine secrete enterogastrones, such as secretin and cholecystokinin?

enteroendocrine cells

Which duct carries bile out of bile ducts in the liver?

common hepatic duct

Which component of bile emulsifies fats?

bile salts

Which vessel delivers nutrient-rich blood to the liver from the digestive tract?

hepatic portal vein

Which chemical activates the transformation of trypsinogen to trypsin?

enteropeptidase

What is a major function of pancreatic juice?

neutralizing chyme entering the small intestine from the stomach

What triggers the release of secretin from the small intestine?

presence of acidic, fatty chyme in the small intestine

Which of the following is NOT inhibited by the intestino-intestinal reflex?

muscularis mucosae

The appendix contains masses of lymphoid tissue and therefore has leukocytes capable of attacking bacteria present in the appendix. But during appendicitis, bacteria trapped in the lumen of the appendix are not effectively attacked because ______.

there is an inadequate blood supply to the appendix wall

The formation of diverticula involves, most significantly, the ______.

weakening of the colon’s submucosa

An effective way to medically treat diarrhea would be to use a drug that ______.

inhibits the activity of the myenteric nerve plexus

Which of the following processes occurs only in the large intestine?

defecation

Which vitamins are made by the bacteria in the large intestine?

B complex and K vitamins

The major function of the large intestine is to __________.

absorb water

__________ can result if food passes too slowly through the large intestine.

Constipation

Bacteria that reside in the large intestine make vitamin K.

True

Which of the following propels food residue over large areas of the colon three to four times a day?

mass movement

What is the function of the bacterial flora that inhabit the large intestine?

Bacterial flora synthesize B-complex vitamins and some of the vitamin K needed by the liver.

Which of the following is the primary function of the large intestine?

defecation

One of the direct consequences of lactose intolerance is ______.

increased osmotic pressure of the large intestine contents

Which enzymes are responsible for the final chemical breakdown of carbohydrates, proteins, and nucleic acids?

brush border enzymes

Proteins are digested into __________.

amino acids

Which of the following are mismatched?

protease: lipid digestion

When a baby ingests breast milk, the milk’s IgA antibodies may be absorbed into the baby’s bloodstream because ______.

many pepsinogen molecules remain unchanged

Which part of the digestive system is the major location for absorption of the end products of digestion?

small intestine

How are fats absorbed into the blood?

in the form of chylomicrons

In cystic fibrosis, blockage of the pancreatic duct by thick mucus will prevent the flow of pancreatic juice into the duodenum; this will directly cause ______.

atrophy of the pancreatic acini

The chemical and mechanical processes of food breakdown are called ________.

digestion

When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________.

chemical digestion

Peristaltic waves are ________.

waves of muscular contractions that propel contents from one point to another

Chemical digestion reduces large complex molecules to simpler compounds by the process of ________.

catabolism

The major means of propulsion through the alimentary canal is peristalsis.

True

The mechanical and chemical receptors that control digestive activity are located ________.

in the walls of the tract organs

The peritoneum is the most extensive serous membrane in the body.

True

The sheets of peritoneal membrane that hold the digestive tract in place are called ________.

mesenteries

From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen.

mucosa, submucosa, muscularis externa, and serosa

If an incision has to be made in the small intestine to remove an obstruction, the first layer of tissue to be cut is the ________.

serosa

The lamina propria is composed of ________.

loose connective tissue

The layer of the digestive tube that contains blood vessels, lymphatic nodules, and a rich supply of elastic fibers is the ________.

submucosa

Which of these is not part of the splanchnic circulation?

inferior vena cava

The submucosal nerve plexus provides the major nerve supply to the GI tract wall and controls GI motility.

False

The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________.

lamina propria

Dentin anchors the tooth in place.

False

Mumps is an inflammation of the parotid glands caused by myxovirus.

True

What part of the tooth bears the force of chewing?

enamel

Which of the following is true concerning the number and type of permanent teeth?

There are 32 permanent teeth, and the wisdom teeth are the last to emerge.

Which of the following is not true of saliva?

contains enzymes that begin the breakdown of proteins

The salivary glands are composed of which two types of secretory cells?

serous cells and mucous cells

The solutes contained in saliva include ________.

electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA

The dental formula for an adult is 2-1-2-3. What does the 1 stand for?

canine tooth

Which of the following are types of papillae on the tongue that contain taste buds?

fungiform and circumvallate

Select the statement that is true concerning primary teeth.

There are 20 primary teeth, and by 24 months of age most children have all 20.

Surgical cutting of the lingual frenulum would occur in which part of the body?

oral cavity

Which of these is not a component of saliva?

a cyanide derivative

A patient has esophageal cancer and must have a feeding tube inserted. The nurse tells the patient that the tube will be inserted surgically into the duodenum. The patient’s wife asks why the tube will not be inserted into the stomach. What should the nurse say?

There is less risk for vomiting, which could cause complications. Digestion is also completed in the small intestines, so there is no need for the stomach with a liquid food diet.

The pharyngeal-esophageal phase of swallowing is involuntary and is controlled by the swallowing center in the thalamus and lower pons.

False

The soft palate rises reflexively to open the nasopharynx when we swallow food.

False

When swallowing, the epiglottis prevents food from entering the larynx.

True

Some of the microbes that often invade other organs of the body are rarely found in the stomach. The reason for this is the presence of HCl.

True

All the chemical and mechanical phases of digestion from the mouth through the small intestine are directed toward changing food into forms that can pass through the epithelial cells lining the mucosa into the underlying blood and lymphatic vessels.

True

Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells.

False

The intrinsic ability of visceral smooth muscle to exhibit the stress-relaxation response is termed plasticity.

True

The stomach’s contractile rhythm is set by pacemaker cells found in the spinal cord.

False

Fats significantly delay the emptying of the stomach.

True

In addition to storage and mechanical breakdown of food, the stomach ________.

initiates protein digestion and denatures proteins

Chyme is created in the ________.

stomach

Hydrochloric acid is secreted by which of the secretory cells of the stomach?

parietal cells

Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones or paracrines that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products?

enteroendocrine cells

There are three phases of gastric secretion. The cephalic phase occurs ________.

before food enters the stomach and is triggered by aroma, sight, or thought

Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of ________.

protein and peptide fragments

Pepsinogen, a digestive enzyme, is secreted by the ________.

chief cells of the stomach

Parietal cells of the stomach produce ________.

hydrochloric acid

Which of the following is not a phase of gastric secretion?

enterogastric

Which vitamin requires intrinsic factor in order to be absorbed?

B12

Nervous control of gastric secretion is provided by ________.

the vagus nerve and enteric plexus

Which of the following produce intrinsic factor?

parietal cells

What stomach secretion is necessary for normal hemoglobin production in RBCs?

intrinsic factor

Select the correct statement about the regulation of gastric secretion.

Gastric secretion can be stimulated before food has entered the mouth.

A baby is admitted to the hospital with a history of projectile vomiting after each feeding. On examination, it is found that the sphincter controlling food passage from the stomach to the duodenum is thickened and does not open readily. Because of the baby’s loss of gastric juice, his blood probably indicates ________.

alkalosis

Hormones or paracrines that inhibit gastric secretion include ________.

secretin

A patient was admitted to the hospital because of severe epigastric pain. He has noted that his stools were darker than the usual brown color. He appears pale and very anxious. The history reports that he drinks 2-3 beers per day and smokes 2 packs of cigarettes a day. Based on the assessment data, what condition might the nurse determine this patient has, and why?

The patient most likely has a bleeding gastric ulcer. The most distressing symptom of a gastric ulcer is gnawing epigastric pain that seems to bore through to the back. As his stools are darker than usual and he is pale and anxious, he probably has a bleeding ulcer.

The relatively unchanging pressure in a filling stomach is due to the contraction of the stomach oblique muscle layer.

False

Gastric accommodation is an example of smooth muscle plasticity.

True

The only essential function of the stomach is to begin the digestion of proteins.

False

Most gastric ulcers are due to excessive production of hydrochloric acid.

False

Which of the following is not a factor that helps create the stomach mucosal barrier?

production of intrinsic factor

Chief cells ________.

produce pepsinogen

Which of the following is (are) not important as a stimulus in the gastric phase of gastric secretion?

carbohydrates

The circular folds of the small intestine enhance absorption by causing the chyme to spiral, rather than to move in a straight line, as it passes through the small intestine.

True

Kupffer cells are found in the liver and are responsible for removing bacteria and worn-out cells.

True

Peyer’s patches are found in the submucosa of the distal end of the small intestine.

True

The digestive function of the liver is to produce bile.

True

The pancreas has both an endocrine and an exocrine function.

True

Another term for swallowing is deglutition.

True

The major stimulus for production of intestinal fluid is distention or irritation of the intestinal mucosa by hypertonic or acidic chyme.

True

Most nutrients are absorbed through the mucosa of the intestinal villi by active transport.

True

Which hormone causes an increased output of enzyme-rich pancreatic juice and stimulates gallbladder contraction to release bile?

cholecystokinin

Choose the incorrect statement regarding bile.

Bile contains enzymes for digestion.

The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ________.

hepatopancreatic ampulla

The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure.

liver

The function of the goblet cells is to ________.

produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion

A fluid secreted into the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is ________.

bile

How are most nutrients absorbed through the mucosa of the intestinal villa?

active transport driven directly or indirectly by metabolic energy

Chemical digestion in the small intestine involves ________.

cholecystokinin (CCK), an intestinal hormone responsible for gallbladder contraction

The ingestion of a meal high in fat content would cause which of the following to occur?

Bile would be released from the gallbladder to emulsify the fat in the duodenum.

The function of the hepatic portal circulation is to ________.

collect absorbed nutrients for metabolic processing or storage

The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task?

plicae circulares, villi, and microvilli

Hepatocytes do not ________.

produce digestive enzymes

Digestion of which of the following would be affected the most if the liver were severely damaged?

lipids

Which of the following is an essential role played by large intestine bacteria?

synthesize vitamin K and B-complex vitamins

There are some 20 known pathogens found in the large intestine; our Ig ________ antibody-mediated response restricts them from going beyond the mucosa and causing problems.

A

A woman is brought to an emergency room complaining of severe pain in her left iliac region. She claims previous episodes and says that the condition is worse when she is constipated, and is relieved by defecation. A large, tender mass is palpated in the left iliac fossa and a barium study reveals a large number of diverticula in her descending and sigmoid colon. Does this woman have diverticulitis or diverticulosis, and why?

She has diverticulitis due to the inflammation of her diverticula.

Which of the following is not characteristic of the large intestine? It ________.

is longer than the small intestine

Paneth cells ________.

secrete enzymes that kill bacteria

The major role of absorption in the ileum is to reclaim bile salts to be recycled back to the liver.

True

You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?

amylase

The enzymatic breakdown of any type of food molecule is called ________.

hydrolysis

Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible?

lipase

Which of the following enzymes is specific for proteins?

trypsin

Select the correct statement about digestive processes.

Chyme entering the duodenum can decrease gastric motility via the enterogastric reflex.

Select the correct statement about absorption.

If intact proteins are transported across the villus epithelium, an immune response may be generated.

Select the correct statement about electrolyte absorption.

Iron and calcium are absorbed mostly by the duodenum.

Ionic iron is actively transported into the mucosal cells, where it binds to the protein ferritin, a phenomenon called the mucosal iron barrier.

True