The Digestive System

Pepsinogen is produced by the:

chief cells of the stomach

The hormone that inhibits gastric emptying is:

cholecystokinin

. Which of these lipoprotein molecules transports excess lipids from cells back to the liver:

. high-density lipoprotein (HDL)

The main function of the esophagus is to

-act on carbohydrates -transport food

An inability of the body to synthesize cholecystokinin would hamper or inhibit:

-the secretion of pancreatic juice -the emulsification of fats

. Substances absorbed by the small intestine are carried to the liver by the:

. hepatic portal vein

Given these parts of the small intestine: 1. duodenum 2. ileum 3. jejunum Choose the arrangement that lists the parts in the order food encounters them as it passes from the stomach through the small intestine.

1,3,2

Given these structures. 1. ascending colon 2. descending colon 3. sigmoid colon 4. transverse colon Choose the arrangement that lists the structures in the order that food encounters them as it passes between the small intestine and the rectum.

1,4,2,3

Given these ducts: 1. common bile duct 2. common hepatic duct 3. cystic duct 4. hepatic ducts Choose the arrangement that lists the ducts in the order bile passes through them when moving from the bile canaliculi of the Iiver to the small intestine

4,2,3,1

The appendix is attached to the:

cecum

Digestion is the:

chemical and mechanical breakdown of food

Following their absorption, simple sugars, fats and amino acids are transported to the liver via the hepatic portal vein.

False

Parasympathetic stimulation inhibits digestion.

False

. Which of these phases of stomach secretion is correctly matched:

Intestinal phase: stomach secretions are inhibited

The vitamin produced by the normal flora of the colon in amounts sufficient to meet a person's daily need is:

K

. By the process of transamination, the liver synthesizes:

Non-essential amino acids

Why doesn't the stomach digest itself?

The stomach wall is protected by large amounts of mucus.

Cells within gastric glands that secret hydrochloric acid are called parietal cells.

True

The presence of chyme in the duodenum slows gastric emptying.

True

Two types of contractions, peristalsis and segmentation, occur in the small intestine.

True

Micelles are:

lipids surrounded by bile salts

. Bile:

a. contains breakdown products from hemoglobin b. emulsifies fats

The gallbladder

a. stores bile b. contracts and releases bile in response to secretin

The enteric nervous system is found in the:

a. submucosa layer b. muscularis layer

The release of secretin is stimulated by the action of

acidic food on the wall of the duodenum

Secretin, gastrin, and CCK in humans are:

all hormones that control digestive secretions

The large intestine absorbs: a. water b. electrolytes c. vitamin B d. vitamin K

all of the above

Which of these might occur if a person suffers from a severe case of hepatitis that impairs liver function a. fat digestion is difficult b. by-products of hemoglobin breakdown accumulate in the blood c. plasma proteins decrease in concentration d. toxins in the blood increase

all of the above

Which of these structures function to increase the mucosal surface of the small intestine: a. circular folds b. villi c. microvilli d. length of the small intestine

all of the above

The pancreas secretes enzymes acting on: a. carbohydrates b. fat c. protein

all of these nutrients

The digestion of protein involves all of these except:

amylase from the pancreas

The primary chemical digestion in the large intestine results from the action of:

bacterial enzymes

Which answer best describes the functions of bacteria in the digestive tract:

breakdown of material not digestible by enzymes

Mechanical digestion includes all of the following except:

conversion of starch to maltose

The liver produces urea to:

detoxify ammonia produced via deamination of proteins

All of the following are areas of the stomach EXCEPT:

duodenum

Chyme is released by the stomach into the:

duodenum

Food is prevented from entering the trachea by the:

epiglottis

The layer of the alimentary tube that is responsible for peristalsis is the:

external muscle layer

All of the following are part of the gastrointestinal tract EXCEPT the:

gallbladder

When food reaches the stomach, secretion of gastric juice is stimulated by the hormone:

gastrin

Which of the following are absorbed into lacteals

triglycerides

The liver synthesizes all of these except:

hemoglobin

. Blood passing through the sinusoids of a lobule of the liver is brought to the liver by the

hepatic artery and portal vein

Which statement is NOT true of the stomach:

hydrochloric acid destroys most microorganisms that enter the stomach because it has a pH of 7-8

The peritoneal cavity:

like the pleural and pericardial cavities, a potential space containing serous fluid

If the thoracic duct were tied off, which of these classes of nutrients would not enter the circulatory system at their normal rate?

lipids

The "brush border" refers to the:

microvilli of the small intestine

Starch digestion is confined to the

mouth and small intestine

Sodium bicarbonate is released from the pancreas to:

neutralize stomach acid as it enters the small intestine

Which of the following lists the tubing in the correct order of food movement:

oropharynx, laryngopharynx, esophagus, stomach, pyloric valve

Although food does not pass through the______, enzymes secreted there are capable of digesting carbohydrates, fats, and proteins.

pancreas

Which of the following is not considered a salivary gland:

pancreas

Obstruction of the hepatopancreatic sphincter impairs digestion by reducing the availability of the:

pancreatic juice and bile

All of the following are substances found in pancreatic juice EXCEPT:

pepsin

Which of the following is NOT an enzyme in the breakdown of carbohydrates:

peptidase

Digested food leaves the stomach via the:

pyloric sphincter

All of the following are functions of the liver EXCEPT:

red blood cell production

Secretin stimulates the:

release of pancreatic juices, particularly the sodium bicarbonate portion

Which of the following human digestive enzymes is incorrectly matched to its substrate

trypsin-nucleic acid

Most digestion and absorption occur in the:

small intestine

Which of the following is NOT an accessory structure of the digestive system:

spleen

Salivary amylase secreted into the oral cavity starts the digestion of:

starch

The muscularis of most organs of the gastrointestinal tract consists of two layers of smooth muscle EXCEPT in the:

stomach

In the small intestine, the Peyer's patches are:

the lymph nodules

Which statement is NOT true of the functions of the liver:

the process of beta-oxidation permits the use of starches for energy production

The site of production of GIP and cholecystokinin is:

the small intestine

Bicarbonate ions diffuse into blood capillaries of the stomach after a meal because:

they are being exchanged for chloride ions that enter the stomach lumen

The secretion of gastric juice and contraction of smooth muscle in the stomach wall are regulated by parasympathetic impulses transmitted via the:

vagus nerves

The fingerlike projections along the surface of the intestines are called:

villi