Q: Which equation best represents the formation of gastric acid in the parietal cells of the stomach?

$$\mathrm{CO_2$} + \mathrm{H_2O} \xrightarrow{\text{carbonic anhydrase}} \mathrm{H_2CO_3} \rightarrow \mathrm{H^+} + \mathrm{$$HCO_3$$^-}$$

Question 1

Which of the following best describes the six primary functions of the digestive system?

Accepted Answer

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation

Question 2

Which tissue type lines the mucosa of the pharynx and esophagus, providing protection against abrasion?

Accepted Answer

Stratified squamous epithelium

Question 3

During peristalsis, which layer of the digestive tract is primarily responsible for the wave-like contractions that propel food?

Accepted Answer

Muscularis externa

Question 4

A patient is unable to properly digest fats due to a blockage in the common bile duct. Which process is most directly affected?

Accepted Answer

Emulsification of lipids by bile

Question 5

Which of the following correctly traces the path of bile from a liver lobule to the duodenal papilla?

Accepted Answer

Bile canaliculi → bile ductules → hepatic ducts → common hepatic duct → cystic duct → common bile duct → duodenal papilla

Question 6

Which equation best represents the formation of gastric acid in the parietal cells of the stomach?

Accepted Answer

$$\mathrm{CO_2$} + \mathrm{H_2O} \xrightarrow{	ext{carbonic anhydrase}} \mathrm{H_2CO_3} ightarrow \mathrm{H^+} + \mathrm{$$HCO_3$$^-}$$

Question 7

Which statement best explains the 'alkaline tide' that occurs after a meal?

Accepted Answer

Bicarbonate ions ($$\mathrm{$$HCO_3$$^-}) $$are released into the blood as gastric acid is produced, temporarily increasing blood pH.

Question 8

Which of the following digestive hormones stimulates the release of pancreatic enzymes and gallbladder contraction?

Accepted Answer

Cholecystokinin (CCK)

Question 9

Which structure in the small intestine increases surface area for absorption by forming finger-like projections?

Accepted Answer

Villi

Question 10

A patient with damage to the lacteals in the villi of the small intestine would have difficulty absorbing which nutrient?

Accepted Answer

Lipids

Question 11

Which of the following best describes the chemical composition of a triglyceride?

Accepted Answer

Three fatty acids bonded to a glycerol molecule

Question 12

Which enzyme is secreted first in the digestion of carbohydrates, and where is it produced?

Accepted Answer

Salivary amylase, produced by the salivary glands

Question 13

Which of the following is the correct order of enzymes involved in protein digestion, including their activation steps?

Accepted Answer

Pepsinogen (stomach) activated to pepsin → trypsinogen (pancreas) activated to trypsin → chymotrypsinogen activated to chymotrypsin → carboxypeptidase

Question 14

Which process allows monosaccharides to be absorbed into the capillaries of the villi in the small intestine?

Accepted Answer

Facilitated diffusion and active transport

Question 15

Which of the following best describes the role of micelles in lipid absorption?

Accepted Answer

Micelles transport fatty acids and monoglycerides to the intestinal epithelium for absorption

Question 16

Which layer of the digestive tract contains blood vessels, lymphatics, and nerves, and supports the mucosa?

Accepted Answer

Submucosa

Question 17

Which of the following is a major function of the liver?

Accepted Answer

Production of bile, metabolism of nutrients, detoxification of blood

Question 18

Which equation best represents the hydrolysis of a disaccharide during carbohydrate digestion?

Accepted Answer

$$\mathrm{C$$_{12}$$H_{22}O$$_{11}} + \mathrm{H_2O} \xrightarrow{	ext{enzyme}} 2\ \mathrm{C_6H_{12}$$O_6$$}$

Question 19

A patient presents with a deficiency in secretin. Which digestive process would be most affected?

Accepted Answer

Release of bicarbonate-rich pancreatic juice to neutralize stomach acid

Digestive System: Anatomy, Physiology, and Chemistry of Digestion

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