Chapter 24 Digestive System

T/F: The enzyme carbonic anhydrase catalyzes the formation of bicarbonate from carbon dioxide and hydrogen.

False

T/F: The external anal sphincter is involuntary

False

T/F: The external anal sphincter is made of smooth muscle

False

T/F: The first step in the formation of hydrochloric acid is the active transport of carbon dioxide into the parietal cells

False

T/F: The medulla oblongata controls gastric secretion both by the parasympathetic branch of the nervous system and the endocrine system.

False

T/F: When chyme enters the duodenum, gastric secretion increases.

False

T/F: You can stop swallowing once you've started.

False

What is the name for component E?

Intrinsic Factor

T/F: Cholecystokinin, which is produced in the small intestine, inhibits gastric secretions in the stomach.

True

T/F: Distention of the stomach has a direct stimulatory effect on the gastric glands.

True

T/F: During the process of retching, the lower esophageal sphincter is open

True

What is the precursor of pepsin?

pepsinogen

Adults normally have ______ permanent teeth; children have ______ deciduous, or primary teeth.

32,20

Which phase of gastric secretion involves thought?

Cephalic Phase

What is the function of hydrochloric acid?

Denatures proteins and causes pepsinogen to be converted to pepsin.

Which is an enzyme that acts to activate other digestive enzymes?

Enterokinase

What is the name for component B?

Pepsin

Which branch will inhibit gastric secretion and mobility?

Sympathetic Nervous System

Why doesn't the stomach digest itself?

The stomach wall is protected by large amounts of mucus.

What muscular organ is responsible in part A for forming the bolus of food?

Tongue

T/F: Secretin is released from the duodenum in response to acidic chyme.

True

Is the tongue an involuntary or voluntary muscle?

Voluntary

All of these occur in the large intestine EXCEPT: a. large numbers of bacteria utilize undigested food. b. fatty acids are absorbed. c. vitamin K is produced. d. sodium and water are absorbed. e. mucus is produced.

b. fatty acids are absorbed.

After food is broken down by digestive enzymes and stomach acid it is called

chyme

Which of the following is part of the small intestine? a. jejunum b. ileum c. duodenum d. All of these are part of the small intestine

d. All of these are part of the small intestine

A baby's first set of teeth are called

deciduous teeth

Which of the following inhibits the secretion of the gastric glands?

duodenum pH of less that two

What blocks the nasopharynx?

soft palate

What are proteins broken down into?

Amino acids

In the parietal cells, the enzyme carbonic anhydrase causes a reaction between

Carbon dioxide and water

The hydrogen ions used to form hydrochloric acid in the stomach are derived from

Carbonic Acid

What is the name for component C?

Hydrochloric Acid

What provides the protective barrier that keeps you from digesting your own stomach?

Mucus

Which of the following hormones does not inhibit gastric gland secretions? a. secretin b. gastrin c. gastric inhibitory peptide d. cholecystokinin

b. gastrin

The hormone ______ stimulates secretion of ______ in the stomach

gastrin, pepsin

The mesentery that connects the greater curvature of the stomach to the transverse colon and covers the small intestines is the

greater omentum

Saliva has all of the following properties EXCEPT secretion is increased primarily by parasympathetic stimulation. contains amylase, which digests carbohydrates. contains lysozyme, which has a weak antibacterial action. has a basic pH

has a basic pH

Secretin is released from the duodenum in response to

hydrochloric acid in chyme

How many layers of muscle does the stomach have in its muscularis externa?

3

T/F: Somatostatin stimulates parietal cells.

False

T/F: Cholecystokinin lowers gastric mobility.

True

Which of the following enzymes is found in saliva? a. betaine b. amylase c. lipase c. cellulase

b. amylase

Which of the following is not an accessory organ of the digestive tract? a. pancreas b. gallbladder c. anus d. liver

c. anus

The most nutrient absorption takes place in the

jejunum and ileum.

Initial chemical digestion of proteins occurs in the ______ by the digestive secretion _______.

stomach; pepsin

The layer of the wall of the digestive tract that contains blood vessels, small glands, and a nerve plexus is the

submucosa layer.

Bands of longitudinal smooth muscle that run the length of the colon are called

teniae coli.

How does the muscularis layer of the esophagus differ from the rest of the digestive tract?

the superior part is skeletal muscle

What structure in the pharynx closes off the trachea and prevents choking?

Epiglottis

What is the name for component D?

Mucus

What is the main type digestion in the stomach?

Protein

Which of the following is not part of the digestive tract? a. mouth b. pancreas c. rectum d. esophagus

b. pancreas

Which phase is 1st?

cephalic

Where does most chemical digestion take place in the small intestine?

duodenum

Besides capillaries, villi also contain lymphatic vessels called

lacteals

What makes bile?

liver

Carbohydrates are broken down into several simple sugars called

monosaccharides

Chemical digestion begins in the

mouth

What type of muscle is the tongue?

skeletal

The lingual frenulum is part of the

tongue

Inside the villus, glucose, amino acids and most ions are absorbed by , while fats and fat soluble substances are picked up by

Capillaries / lacteals

After the food moves into the upper esophagus, what do the superior pharyngeal constrictor muscles do?

Contract

A deficiency of one of the components listed above can result in a gastric ulcer or erosion. Which substance is it?

D

A deficiency in one of the components listed above can result in anemia, which substance is it?

E

What is the function of the intrinsic factor?

Essential for the absorption of vitamin B12.

T/F: In the Buccal phase, the soft palate rises to block the nasopharynx

False

T/F: Once food is acidified in the stomach, amylase continues to digest starch

False

T/F: Pancreatic amylase is responsible for the majority of fat digestion

False

T/F: The carbonic acid ion is joined to a hydrogen ion by the enzyme carbonic anhydrase.

False

What is the name for component F?

Gastrin

Which transporters are responsible for transporting monosaccharides out of the cell?

Glucose

All of the following contribute to absorptive surface of the small intestine except,

Haustra

What major vessel transports nutrients from the intestine to the liver?

Hepatic portal vein

________ ions are actively transported into the gastric gland duct, in exchange for ________ ions which enter the parietal cells.

Hydrogen, Potassium

Does the intestinal phase stimulate gastric secretion or inhibit it?

Inhibit

Is the swallowing reflex involuntary or voluntary?

Involuntary

Bruce just finished a super double extra value meal at his local fast food restaurant. His pants are now feeling a bit tight, and he feels a rumbling in the upper left quadrant of his abdomen. What does the rumbling in Bruce's abdomen reflect?

Mechanical digestion by the three muscular layers of the stomach

Which branch of the autonomic nervous system will stimulate gastric secretion and mobility?

Parasympathetic Nervous System

______ stimulation via the ______ nerve causes the secretion of HCI in the stomach.

Parasympathetic, vagus

What is the name for component A?

Pepsinogen

What type of specialized muscle contraction moves food through the esophagus and to the stomach?

Peristalsis

After the bolus is formed, what structure does the bolus move to next?

Pharynx

Which transporters are responsible for transporting monosaccharides across the intestinal cell membrane into the cell?

Sodium glucose

What are the two triggers that initiate the gastric phase of gastric secretion?

Stretching stomach and rise in gastric pH

T/F: Gastrin functions to increase the production of HCl in the stomach.

True

T/F: Gastrin stimulates gastric glands to release more gastric juices.

True

T/F: In the parietal cell, carbonic acid dissociates into a bicarbonate ion and a hydrogen ion

True

T/F: Parietal Cells secrete HCl

True

T/F: Polymers MUST be broken down into monomers to be absorbed by our cells

True

he ion exchange protein in the plasma membrane of parietal cells exchanges ________ ions going out for ________ ions coming in.

bicarbonate, chloride

Which of the following enzymes is produced by the stomach? a. insulin b. secretin c. pepsin d. trypsin e. chymotrypsin

c. pepsin

Gastric secretion begins during the _______ phase and ends during the ______ phase.

cephalic, intestinal

A lab group is sent to the cafeteria to do an experiment. The instructions direct each student to obtain a regular saltine cracker and to chew it 25 times before swallowing. The students are to observe and record the initial and final tastes of the cracker. Most students record that the cracker initially tastes salty, but then tastes sweet. Which of the following correctly explains the students' observations? a. The salt on the crackers dissolved rapidly in saliva and was quickly detected by taste buds. b. Salivary amylase digested the cracker's starch into sugars that could be then be tasted. c. Lingual lipase digested the cracker's fat into sugars that could then be tasted. d. A and B are correct. e. A and C are correct.

d. A and B are correct.

Which of the following does not occur during the gastric phase of gastric secretion? a. Gastrin begins to be secreted by the lower part of the stomach b. Hydrochloric acid and pepsin secretion is stimulated in the upper and middle parts of the stomach c. Tactile sensation of food in the mouth sends nervous impulses to the medulla oblongata d. All of the choices are correct e. None of the choices are correct

d. All of the choices are correct

Which of the following does NOT stimulate the secretion of HCI in the stomach? a. the smell of food b. the taste of food c. the distention of the stomach as it fills with food d. secretin e. All of the options listed stimulate secretion of HCI in the stomach

d. secretin

Hydrochloric acid is formed when

hydrogen ions and chloride ions join in the duct of the gastric gland

Which part of the brain controls the gastric regulation?

medulla oblongata

Bile acid droplets are also known as

micelles

Which layer is the innermost layer?

mucosa

The exit of the stomach, which is sometimes stenosed in infants, is the

pylorus

Large mucosal folds formed when the stomach is empty are called

rugae

Which of the following organs is part of the digestive tract or alimentary canal?

stomach