exam 3 part 2

List the components of the gastrointestinal tract beginning with the intake of food

and ending with the elimination of waste products:

Mouth

Pharynx

Esophagus

Stomach

Small intestine

Large intestine

List four examples of accessory digestive organs:

Salivary glands

Liver

Gall bladder

Pancreas

Which of the following is an accessory digestive organ that does not participate in the

chemical digestion of food?

a. Gall bladder

b. Liver

c. Salivary glands

d. Tongue

e. Pancreas

d. Tongue

List the six processes associated with the digestive system:

ingestion

Mechanical breakdown

Propulsion

Digestion

Absorption

Defection (elimination)

Which of the following is not an example of mechanical breakdown?

a. Chewing

b. Peristalsis

c. Segmentation

d. Churning

b. Peristalsis

Churning occurs in the ____ and segmentation takes place in the ____.

stomach/small intestine

The movement of products of digestion from the intestinal tract into circulation is known as ____

absorption.

The double-layered serous membrane lining the abdominal cavity is the ___

peritoneum.

Which of the following is retroperitoneal?

a. Liver

b. Gall bladder

c. Stomach

d. Jejunum of the small intestine

e. Duodenum of the small intestine

e. Duodenum of the small intestine

A double layer of peritoneum that extends from the body wall to digestive organs is the ____

mesentery

Which of the following is false concerning mesentery?

a. The liver is suspended by ventral mesenteries

b. Most intraperitoneal digestive organs are suspended by dorsal mesenteries

c. Provide a route for blood vessels, lymphatic vessels, and nerves that supply

the gastrointestinal tract

d. Hold digestive organs in place

e. All of the above are true concerning mesenteries

e. All of the above are true concerning mesenteries

List three functions of mesentery:

Hold digestive organs in place

Route for blood vessels, lymphatic vessels, and nerves

Fat storage

List the four layers of the gastrointestinal tract, beginning with the most external layer:

Mucosa

Submucosa

Muscularis externa

Serosa

Mucosa

Comprised of epithelial cells; functions include secretion, absorption,

and protection

Submucosa

includes enteric nerves, nerves from the central nervous system,

blood and lymphatic vessels

Muscularis externa

Responsible for segmentation, peristalsis, and the formation of

sphincters

Serosa

Outermost layer; forms the visceral peritoneum

Intrinsic regulation of the GI tract includes:

a. Hormones and enteric nerves

b. Hormones and autonomic nerves

c. Enteric and autonomic nerves

d. Enteric nerves and paracrine regulators

e. Paracrine regulators and hormones

d. Enteric nerves and paracrine regulators

The system of intrinsic sensory neurons that are not part of the autonomic nervous system is the ____ nervous system

enteric

Which of these is not secreted in the mouth?

a. Antimicrobial proteins

b. Amylase

c. Ghrelin

d. Mucus

e. All of the above are secreted in the mouth

c. Ghrelin

What two specific processes are associated with the mouth?

a. Propulsion and mechanical breakdown by churning

b. Mechanical breakdown by chewing and segmentation

c. Mechanical breakdown by chewing and digestion by amylase

d. Digestion by amylase and digestion by pepsin

e. Digestion by amylase and propulsion

c. Mechanical breakdown by chewing and digestion by amylase

What is the only process associated with the pharynx and esophagus?

Propulsion by swallowing (deglutition)

Which of the following is not a process that takes place in the stomach?

a. Mechanical breakdown by churning

b. Peristalsis

c. Chemical digestion by pepsin

d. Absorption NOTE: Absorption is minimal and is limited to alcohol and certain drugs

e. All of the above take place in the stomach

e. All of the above take place in the stomach

Which of the following is false concerning the stomach?

a. Additional functions include innate immunity and food storage

b. Absorption of alcohol and several other drugs takes place in the

stomach

c. Moves chyme across the pyloric sphincter into the small intestine

d. Begins the process of protein digestion

e. All of the above are true concerning the stomach

e. All of the above are true concerning the stomach

The gastric pits of the stomach are comprised of numerous secretory cells known as _____ glands.

gastric

What are the two functions of HCl in the stomach?

Immune: Acidic environment to kill bacteria

Digestive: Activation of pepsinogen to pepsin

List the four types of gastric gland cells found in the stomach:

Chief cells

Parietal cells

Enteroendocrine cells

Mucus cells

Parietal cells

• Intrinsic factor

• HCl

Chief cells

Pepsinogen

Enteroendocrine cells

• Gastrin

• Histamine

• Paracrine chemicals

The only essential digestive function performed by the stomach is:

a. Initiation of protein digestion

b. Churning of food

c. Secretion of gastrin

d. Secretion of intrinsic factor

e. Propulsion of food

d. Secretion of intrinsic factor

Ghrelin

• Stimulates hunger in the hypothalamus

Intrinsic factor

Required for the ability of the small intestine to absorb vitamin B-12

Gastrin

Stimulates secretion of HCl by parietal cells and stimulates the

activation of smooth muscle in the small intestine

Protein digestion in the stomach begins when _____ secreted by the parietal cells activates ___—- (secreted by chief cells) to ______. This enzyme then breaks proteins into large polypeptides.

• HCl

• pepsinogen

• pepsin

The mixture of partially digested food and digestive juices that passes through the pyloric sphincter into the small intestine is ____

chyme

Ulcers that form in the stomach are known as _____ ulcers

gastric

Which of the following is a false statement?

a. Ulcers may also form in the esophagus and duodenum of the small intestine

b. Most ulcers result from infection by the bacterium Helicobacter pylori

c. Heartburn results from the backflow of stomach acid into the esophagus

d. Most digestion and absorption of food occurs in the stomach

e. All of the above are true concerning the stomach

d. Most digestion and absorption of food occurs in the stomach

Which of the following is false concerning food leaving the stomach?

a. Has undergone mechanical breakdown by chewing in the mouth and churning

in the stomach

b. Starch has been partially digested by salivary amylase

c. Proteins have been partially digested by pepsin

d. Enters the duodenum as chyme

e. All of the above are true concerning food leaving the stomach

e. All of the above are true concerning food leaving the stomach

List the five categories of liver function and give an example of each:

Detoxification of blood

Carbohydrate metabolism

Lipid metabolism

Protein synthesis

Secretion of bile

What role does the liver play in digestion?

Production of bile that is required for emulsification of fats to permit

digestion by lipase

Inflammation of the liver is known as ______ and chronic inflammation can result in the formation of non-functional scar tissue that causes a condition known as _____

hepatitis/ cirrhosis

Bile from the liver or gall bladder enters the ____ of the small intestine via the _____. After use in aiding the digestion of fats, most bile salts are reabsorbed from the ileum of the small intestine and return to the liver via the _____vein.

duodenum/bile duct/ hepatic portal

List the four classes of pancreatic enzymes:

Proteases

Lipase

Amylase

Nucleases

What three inactive enzymes are secreted by the pancreas that are activated in the small intestine and used for protein digestion?

Trypsinogen

Chymotrypsinogen

Carboxypeptidase

An enzyme secreted in an inactive form that is activated by some chemical process in its target organ is known as a ____

zymogen

List the two functions of the small intestine:

Completion of digestion

Nearly all absorption

In addition to the small intestine, where else does digestion occur?

a. Liver

b. Mouth

c. Stomach

d. A and B

e. B and C

e. B and C

In addition to the small intestine, where else does absorption of nutrients occur?

a. Stomach

b. Large intestine

c. Pancreas

d. Gall bladder

e. Esophagus

b. Large intestine

List the three regions of the small intestine and indicate which are intraperitoneal and which are retroperitoneal:

Duodenum - Retroperitoneal

Jejunum - Intraperitoneal

Ileum - Intraperitoneal

Movement of food from the stomach to the small intestine is controlled by the ____ sphincter and movement into the large intestine is controlled by the ____ valve.

pyloric/ ileocecal

Which of these is a modification of both the submucosa and mucosa for increasing

surface area?

a. Villi

b. Microvilli

c. Enterocytes

d. Circular folds

e. Intestinal crypts

d. Circular folds

List two modifications of only the mucosa for increasing surface area:

Villi

Microvilli

Which of the following is not found within villi?

a. Mucosa-associated lymphoid tissue

b. Lacteals

c. Duodenal glands

d. Blood capillaries

e. All of the above are found within villi

c. Duodenal glands

Enterocytes

Secrete intestinal juice with intestinal crypts; Form microvilli specialized for absorption

Goblet cells

Found within intestinal crypts and villi of mucosa; secrete mucus

Enteroendocrine cells

Secrete two hormones

Paneth cells

Secrete defensins and lysozymes

Stem cells

Found deep within intestinal crypts; differentiate into other types of villi cells

Duodenal cells

Located in the submucosa; secrete bicarbonate and mucus

Absorption of digested nutrients is a function of:

a. Enterocytes

b. Goblet cells

c. Enteroendocrine cells

d. Paneth cells

e. Stem cells

a. Enterocytes

Which of the following is not a function of CCK and secretin?

a. Inhibit gastric secretions and gastric motility

b. Increase production and secretion of pancreatic juice

c. Increase bile output by liver

d. Inhibit bile secretion by bile duct

e. All of the above are functions of CCK and secretin

d. Inhibit bile secretion by bile duct

List three functions of the large intestine:

Absorption of remaining water and electrolytes

Absorption of products from bacterial metabolism

Storage and elimination of waste

Which of the following is not absorbed in the large intestine?

a. Amino acids

b. Vitamin K

c. Water

d. Electrolytes

e. All of the above are absorbed in the large intestine

a. Amino acids

Pocket-like sacs of the large intestine are known as _____.

haustra

Which of the following is NOT part of the pathway taken by food as it enters the large

intestine from the small intestine?

a. Ascending colon

b. Descending colon

c. Transverse colon

d. Cecum

e. Sigmoid colon

d. Cecum

Which of the following is false concerning the large intestine?

a. Lacks circular folds, villi, and microvilli

b. Contains deep intestinal crypts lined with goblet cells

c. Most epithelial cells as specialized for absorption

d. Supports more than 1,000 different types of bacteria

e. All of the above are true of the large intestine

c. Most epithelial cells as specialized for absorption

The various species of bacteria living in the large intestine are known as

the bacterial ______

microbiota (microflora)

Intestinal bacteria are especially important because of their ability to synthesize:

a. Vitamin B-12

b. Vitamin K

c. Vitamin A

d. Amino acids

e. Sodium

b. Vitamin K

Appendicitis

Results from blockage of an extension of the cecum that results in bacterial infection, loss of blood supply, and tissue damage in that area

Antibiotic-associated diarrhea

Results from infection with bacteria such Clostridium difficile and

administration of drugs that destroy beneficial bacteria

Irritable bowel syndrome

A functional disorder of the digestive tract that is not explained by anatomical or biochemical abnormalities; may be related to stress

Diverticulitis

Occurs when herniations of the mucosa, caused by increased pressure on the wall of the large intestine, become inflamed and rupture

Inflammatory bowel disease

May result from an imbalance between bacterial species that mediate two opposing functions of the immune system

Movement of substances from lumen of the gut into the body is ____

absorption

Excluding the stomach, what are the four specific regions of the digestive tract where absorption occurs and in which region does the most absorption occur?

Duodenum of small intestine

Jejunum of small intestine – Most absorption

Ileum of small intestine

Large intestine

What is absorbed in the stomach?

Alcohol and some drugs

Which of the following is not absorbed into blood capillaries?

a. Amino acids

b. Water

c. Fatty acids

d. Minerals

e. Simple sugars

c. Fatty acids

Lymphatic capillaries that absorb monoglycerides and fatty acids from the small intestine are known as _____. Ultimately, these absorbed products enter circulation as ____ via the _____

lacteals/ triglycerides/ thoracic duct

Substances absorbed into blood capillaries are first transported to the:

a. Pancreas

b. Tissues

c. Heart

d. Lungs

e. Liver

e. Liver

The ______ membrane (brush border) of the small intestine is specialized for the absorption of substances from the digestive tract. These substances then move out of intestinal epithelial cells via the ____ membrane.

apical/ basolateral

What are the four specific regions of the digestive tract where digestion occurs and in which region does the most digestion occur?

Mouth

Stomach

Duodenum of small intestine -- Most digestion

Jejunum of small intestine

Disaccharides are digested by enzymes produced in the:

a. Small intestine

b. Liver

c. Large intestine

d. Stomach

e. Pancreas

a. Small intestine

Starch digestion is initiated by amylase, produced by the _____ in the mouth and completed by amylase, produced by the _____ in the small intestine. Amylase results in the production the disaccharide _____ that is split into individual glucose monomers by the brush border enzyme _____

salivary glands/ pancreas/ maltose/ maltase

A genetic defect in what enzyme results in an intolerance for dairy products?

a. Sucrase

b. Lipase

c. Lactase

d. Trypsin

e. Carboxypeptidase

c. Lactase

Proteins are digested into large polypeptides in the _____by the _______enzyme

a. Small intestine/Trypsin

b. Small intestine/Pepsin

c. Stomach/Pepsin

d. Stomach/Trypsin

e. Large intestine/Chymotrypsin

c. Stomach/Pepsin

Which of the following is not a pancreatic enzyme that digests large

polypeptides into small polypeptides?

a. Trypsin

b. Chymotrypsin

c. Pepsin

d. Carboxypeptidase

e. All of the above are pancreatic enzymes that digest large polypeptides into

small polypeptides

c. Pepsin

Which of the following is an example of a brush border enzyme that removes individual amino acids from small polypeptides?

a. Maltase

b. Chymotrypsin

c. Trypsin

d. Aminopeptidase

e. Lipase

d. Aminopeptidase

Which of the following is a false statement concerning lipid digestion?

a. Nearly all lipid digestion occurs in the large intestine

b. Results in the production of monoglycerides and fatty acids

c. Requires bile that is produced by the liver

d. Lipase, produced by the pancreas, is responsible for lipid digestion

e. All of the above are true concerning lipid digestion

a. Nearly all lipid digestion occurs in the large intestine

Nucleic acid digestion begins with the pancreatic enzymes _____ and ____ and is completed by phosphatases and ______ produced by the brush border of the small intestine.

ribonuclease/ deoxyribonuclease/ nucleosidases