Human Anatomy and Physiology : Help with Stomach Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #2 : Digestive Physiology

Which stomach cell is responsible for the activation of pepsinogen?

Possible Answers:

Parietal cells

Chief cells

G cells

Goblet cells

Correct answer:

Parietal cells

Explanation:

Pepsinogen is an inactive enzyme that is released into the stomach lumen by chief cells. Parietal cells are responsible for secreting hydrochloric acid. This acid will cleave the pepsinogen and make it an active enzyme, pepsin, which can then cleave peptide bonds and begin protein digestion.

Goblet cells secrete mucus to protect the epithelium of the stomach from the acid in the lumen. G cells secrete gastrin, which promotes the secretion of hydrochloric acid and pepsinogen.

Example Question #3 : Digestive Physiology

Stratified squamous epithelium can be found in all of the following except in the __________.

Possible Answers:

stomach

oral cavity

oropharynx

esophagus

anal canal

Correct answer:

stomach

Explanation:

Stratified squamous epithelium protects tissues in areas that are prone to abrasion. This lining consists of many layers and is typically located on the areas near/associated with the mouth, excretory system, and the esophagus. The stomach does not have a stratified squamous epithelial lining, as it instead uses simple columnar epithelium.

Example Question #4 : Digestive Physiology

Which of the following is not a function of the stomach?

Possible Answers:

Denaturation of proteins

Mechanical breakdown of food

Storage of ingested food

Initiation of protein digestion

Absorption of triglycerides

Correct answer:

Absorption of triglycerides

Explanation:

The stomach stores ingested food, denatures proteins, initiates protein digestion, and mechanically breaks down food. The absorption of triglycerides, or lipids, takes place in the small intestine.

Example Question #5 : Digestive Physiology

Which of the following exits the stomach most quickly during gastric emptying?

Possible Answers:

Isotonic liquids

Hypertonic liquids

Protein-rich particulates

Hypotonic liquids

Fatty particulates

Correct answer:

Isotonic liquids

Explanation:

Liquids exit the stomach more quickly than solids, and isotonic solutions exits more quickly than hypertonic or hypotonic solutions. As such, isotonic liquids will exit the stomach most quickly during gastric emptying.

Solids exit the stomach in the general order of carbohydrates, followed by proteins, followed by fats.

Example Question #1 : Help With Stomach Physiology

Which stomach cell type secretes the  that converts pepsinogen to pepsin in the stomach and, secretes intrinsic factor, for vitamin B12 absorption later in the gastrointestinal tract?

Possible Answers:

Parietal cells

Goblet cells

G-cells

Chief cells

Correct answer:

Parietal cells

Explanation:

Goblet cells secrete mucous, which protects the stomach lining. Chief cells secrete pepsinogen, which must be converted to pepsin by acid in order to carry out its function of breaking down proteins. G-cells secrete gastrin, increase secretion from the other cells, and induce muscle contractions. Parietal cells secrete both  and intrinsic factor.

Example Question #2 : Help With Stomach Physiology

Which of the following describes venous blood leaving the stomach? 

Possible Answers:

Basic in pH

Basic in pH when food is present, and acidic in pH when food is absent

Acidic in pH

Neutral in pH

Acidic in pH when food is present, and basic in pH when food is absent

Correct answer:

Basic in pH

Explanation:

Since the stomach releases  ions into the stomach, it releases bicarbonate into its venous supply, which can feed into the pancreas. This allows the pancreas to release the bicarbonate into the lumen to help neutralize the stomach acid. Remember, the venous blood leaving the pancreas is acidic in nature and can help provide the stomach with a supply of  ions for its functionality. 

Example Question #3 : Help With Stomach Physiology

Which of the following is not a function of hydrochloric acid in the stomach?

Possible Answers:

It nonspecifically destroys pathogens

It lowers the pH of the stomach, bringing it to pepsin's optimum

It denatures peptide bonds in the protein

It helps activate pepsinogen into the enzyme pepsin

It denatures the protein by breaking down the protein's quaternary and tertiary structure

Correct answer:

It denatures peptide bonds in the protein

Explanation:

Hydrochloric acid does not break peptide bonds. Instead, it is responsible for breaking down the quaternary and tertiary structure of the protein, leaving the peptide bonds more accessible for pepsin to break. Pepsin is responsible for breaking the bonds between the amino acids, which is known as proteolysis. Lastly, the acidic environment of the stomach kills many microbes, preventing infection.

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