Ch. 18: Digestive System Module

The proximal area of the pyloric region is called the pyloric _____________.

Antrum

Parietal cells secrete __________ into the lumen of the stomach and __________ into the bloodstream.

H+ and Cl-; HCO3-

Components of gastric juice include ________, __________, _________, and _________.

H+, Cl-; water; pepsin; intrinsic factor

The ATPase pump in the apical membrane of parietal cells moves ________ into the cells while transporting ________ out of the cells.

K+; H+

Entry of ______________ into parietal cells from the bloodstream exchanges Cl- and bicarbonate ions (HCO3-), provides Cl- for secretion into the stomach lumen, and occurs by secondary active transport.

chloride ions (Cl-)

The duodenum of the small intestine receives __________, containing initial products of the chemical digestion of __________ and starch.

chyme; protein

The components of the submucosa are supported by _________, located between muscularis mucosae and muscularis externa.

connective tissue

The components of the submucosa are supported by ___________, located between muscular is mucosae and muscular is extern.

connective tissue

The intestinal phase of gastric regulation is facilitated by events that occur in the ____________, where chyme stimulates the release of hormones and receptors that initiate inhibitory neural reflexes.

duodenum

Bile (salt) ____________ lipids.

emulsifies

Organic molecules in __________ are used for the synthesis of macromolecules, cells, and tissues in the human body.

food

G cells secrete _______________.

gastrin

A hormone produced by the stomach that may regulate hunger is called _____________.

ghrelin

Microscopic folds in the gastric mucosa form gastric ____________, lined with cells that produce the components of gastric juice; the openings of the folds into the stomach lumen are called gastric _____________.

glands; pits

The most important function of the stomach is the secretion of ______________, which is needed for the absorption of vitamin B12 in the small intestine.

intrinsic factor

The layer of the wall of the gastrointestinal tract responsible for absorption, protection, and secretion, is the ____________.

mucosa

A non-enzymatic secretion of salivary glands, _________ facilitates bolus formation during mastication.

mucus

Folds in the wall of certain regions of the gastrointestinal tract that increase the absorptive surface area are created by the __________________.

muscularis mucosae

Pepsin specifically hydrolyzes __________ bonds in ____________.

peptide; proteins

During the esophageal of deglutition, the bolus is moved toward the stomach by rhythmic contractions of the muscular is extern called _______________.

peristalsis

Complete digestion of _______ occurs in the small intestine, in the absence of pepsin and around pH 8.

protein

The small intestine extends from the ________ sphincter, proximally, to the ___________ valve, distally.

pyloric; ileocecal

The arrival of chyme in the duodenum stimulates the secretion of ___________ and ___________, both of which stimulate the secretion of pancreatic juice.

secretin; CCK

ECL cells secrete ___________.

serotonin, histamine

The largest part of the intestinal tract is the _______________.

small intestine

D cells secrete ______________.

somatostatin

The ___________ connects the esophagus and the duodenum.

stomach

The most distensible organ of the digestive system is the _____________.

stomach

Sucrose is hydrolyzed by _______________, lactose is hydrolyzed by ____________, and the general name for the products of these hydrolysis reactions is _____________.

sucrase; lactase; monosaccharide

External or "extrinsic" control of motility and secretion in the gastrointestinal tract is afforded by ___________________ and ______________.

the ANS and hormones

The esophageal phase of deglutition begins when the __________ relaxes, permitting entry of the bolus into the esophagus.

upper esophageal sphincter

Digestive enzymes direct reactions which may break covalent bonds in both food and ___________ molecules.

water

In the digestive system, the transport of the products of hydrolytic enzyme activity across the mucosal layer into the blood or lymph is called _____________.

absorption

Inhibitory peptides are released from pepsinogen by ________, freeing the fully active enzyme pepsin.

acid

Cells of the pancreatic ________________ secrete digestive enzymes into pancreatic juice.

acini

The exocrine function of the pancreas is performed by pancreatic __________.

acini

Complete hydrolysis of the products of the actions of salivary amylase and pancreatic amylase is accomplished by ___________.

brush border enzymes

The bicarbonate ions (HCO3-) exchanged for chloride ions (Cl-) at the basolateral surface of parietal cells is formed by the dissociation of carbonic acid (H2CO3), produced by the enzyme _________ from CO2 and H2O.

carbonic anhydrase

Vagal regulation of gastric secretion and motility by the CNS prior to the arrival of food in the stomach, is called the ____________ phase.

cephalic