Gastric Digestion Process

What happens to the ionization of polar molecules in the gastric lumen?

It alters (correct)
It increases
It remains the same
It disappears

What is not dissolved by acid in the stomach?

Salts
Proteins
Polysaccharides
Fat (correct)

What is the purpose of hydrochloric acid in the stomach?

To produce enzymes
To kill bacteria (correct)
To digest proteins
To absorb nutrients

What is the result of the digestive actions of the stomach?

A solution known as chyme (D) Signup and view all the answers

What is the diameter of the small intestine?

1.5 inches (C) Signup and view all the answers

Where do the final stages of digestion and most absorption occur?

Small intestine (B) Signup and view all the answers

What is the main function of micelles in the small intestine?

To provide a means of keeping most of the insoluble fat digestion products in small soluble aggregates (A) Signup and view all the answers

Which of the following is NOT a component of micelles?

Proteins (C) Signup and view all the answers

What happens to the contents of micelles when they break down?

They are released into the solution and become available to diffuse across the intestinal lining (A) Signup and view all the answers

What is the purpose of the polar ends of each molecule in micelles?

To orient towards the micelle's surface (C) Signup and view all the answers

What is the result of the continuous breakdown and reformation of micelles?

A constant supply of lipids available to diffuse into the intestinal epithelium (D) Signup and view all the answers

What is included in the core of the micelle, in addition to fatty acids and monoglycerides?

Small amounts of fat-soluble vitamins and cholesterol (B) Signup and view all the answers

What is the effect of secretin on pancreatic bicarbonate secretion?

It strongly stimulates pancreatic bicarbonate secretion (D) Signup and view all the answers

What is the result of the interaction between secretin and CCK?

CCK potentiates the effect of secretin on pancreatic bicarbonate secretion (A) Signup and view all the answers

What is the consequence of potentiation on the actions of gastrointestinal hormones?

Small changes in the plasma concentration of one hormone have a large effect on other hormones (C) Signup and view all the answers

What type of effects do gastrointestinal hormones have on various tissues?

Tropic (growth-promoting) effects (C) Signup and view all the answers

How many phases of gastrointestinal control are mentioned in the text?

Three phases (B) Signup and view all the answers

What is the location of the stimulus that determines the phase of gastrointestinal control?

The location of the stimulus (D) Signup and view all the answers

What stimulates the secretion of the salt solution by the bile ducts?

Secretin in response to the presence of acid in the duodenum (A) Signup and view all the answers

What controls the secretion of bile salts?

The concentration of bile salts in the blood (D) Signup and view all the answers

What happens to bile secretion during and just after a meal?

It increases (C) Signup and view all the answers

What is the function of the sphincter of Oddi?

To block bile from flowing into the duodenum (D) Signup and view all the answers

What happens to bile in the gallbladder?

It becomes more concentrated (D) Signup and view all the answers

What is the signal for gallbladder contraction and sphincter relaxation?

The intestinal hormone CCK (D) Signup and view all the answers

What is the process of inserting H,K-ATPases into the plasma membrane regulated by?

Four chemical messengers: gastrin, acetylcholine, histamine, and somatostatin (B) Signup and view all the answers

What is the effect of somatostatin on acid secretion?

It inhibits acid secretion (C) Signup and view all the answers

What is the role of histamine in stimulating acid secretion?

It markedly potentiates the response to other stimuli (D) Signup and view all the answers