NCLEX : General Biology

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #21 : General Biology

What is the function of gastrin in the digestive tract?

Possible Answers:

All of these are true

Triggers chief cells to secrete pepsinogen

Increases gall bladder emptying

Triggers parietal cells to release 

Correct answer:

All of these are true

Explanation:

Gastrin, a peptide hormone released by G-cells of the stomach, has many functions in digestion. It triggers parietal cells to release , it increases gastric motility, it triggers chief cells to secrete pepsinogen, and it stimulates the gallbladder to release bile. 

Example Question #324 : Nclex

Which of the following is not a brush border enzyme?

Possible Answers:

Sucrase

Carboxypeptidase

Lactase

All of these are brush border enzymes

Correct answer:

All of these are brush border enzymes

Explanation:

The intestinal brush border is the microvilli-covered surface of the small intestine. It is where a large part of the digestive process occurs, aided by brush-border enzymes such as sucrase, maltase, lactase, and carboxypeptidase. 

Example Question #22 : General Biology

Which of the following is not an enzyme secreted by the pancreas?

Possible Answers:

Amylase

Lipase

Insulin

Carboxypeptidase

Correct answer:

Insulin

Explanation:

Insulin, while secreted by the pancreas, is not an enzyme. Rather it is a peptide hormone that plays a role in lipid and blood sugar metabolism.

The other enzymes listed are all pancreatic enzymes that play a role in digestion. Amylase breaks down carbohydrates, while lipase and sterol esterase break down fats. Carboxypeptidase is an enzyme that removes the final amino acid group from a protein.

Example Question #23 : General Biology

What cells of the stomach secrete hydrochloric acid ?

Possible Answers:

Chief cells

Parietal cells

Foveolar cells

M cells

Correct answer:

Parietal cells

Explanation:

 is secreted by parietal cells of the stomach. Chief and foveolar cells of the stomach secrete pepsinogen and mucus respectively, and M cells are not stomach cells, but rather intestinal cells involved in mucosa-associated lymphoid tissues, or MALT. 

Example Question #24 : General Biology

Mastication and peristalsis are examples of what type of digestion?

Possible Answers:

Oral

Chemical

Mechanical

Physical

Correct answer:

Mechanical

Explanation:

The two main forms of digestion and chemical and mechanical. Mechanical digestion involves the physical crushing, mixing, and breaking down of food particles into small pieces or slurries. Mechanical digestion primarily occurs with mastication and is carried out to some degree by peristaltic contractions of the stomach and intestine. Chemical digestion is the further breakdown of food particles into their molecular parts. This is carried out primarily via enzymes, HCl, and bile.

Example Question #25 : General Biology

What is a normal transit time for the stomach?

Possible Answers:

2 to 6 hours

10 to 12 hours

10 minutes to 4 hours

5 to 10 minutes

Correct answer:

10 minutes to 4 hours

Explanation:

Stomach transit time varies widely: it can take anywhere from ten minutes to four hours for food to pass through the pyloric sphincter into the duodenum. Transit time in the stomach is affected by the composition of the meal, and by the individual's rate of gastric emptying. Transit time may be shortened due to consumption of liquid or simple-carbohydrate foods, or lengthened in the case of consumption of solid food that has a high protein or fiber content.

Example Question #26 : General Biology

What is the normal transit time of food through the small intestine?

Possible Answers:

8-12 hours

12-18 hours

1-2 hours

3-8 hours

Correct answer:

3-8 hours

Explanation:

Normal transit time of food through the small intestine is three to eight hours. This is significantly longer than transit time through the stomach due to the wider variety of digestive processes that occur in the small intestine, including the catabolism of proteins, lipids, nucleic acids, and simple and complex carbohydrates.

Example Question #27 : General Biology

What is the average transit time of the colon?

Possible Answers:

24-32 hours

2-4 hours

8-16 hours

16-24 hours

32-48 hours

Correct answer:

32-48 hours

Explanation:

The average colon transit time for both adults and children is between 32 and 48 hours. This is significantly longer than the transit times of food through the stomach and small intestine, which averages 4-12 hours total. A slow transit time through the colon can be increased by various lifestyle factors such as exercise and hydration, and  dietary changes such as an increase in fiber-rich foods and avoidance of food allergies or other constipation triggers.

Example Question #28 : General Biology

Which of the following structures is the main blood supply to the small intestine?

Possible Answers:

Left gastric

Right hepatic

Inferior mesenteric

Superior mesenteric

Correct answer:

Superior mesenteric

Explanation:

The main artery supplying blood to the small intestine is the superior mesenteric artery. This vessel branches off the abdominal aorta and supplies the lower part of the duodenum, the ileum, the jejunum, and two-thirds of the transverse colon. The rest of the colon and the rectum are supplied by the inferior mesenteric artery, while the right hepatic and left gastric supply the liver and stomach, respectively.

Example Question #29 : Gastrointestinal Physiology

All of the following are salivary glands except:

Possible Answers:

Thymus gland

Parotid gland

Sublingual gland

Submandibular gland

Correct answer:

Thymus gland

Explanation:

We have three main types of salivary glands: the parotid glands, the submandibular glands, and the sublingual glands. The thymus gland is not a salivary gland, and is located in the chest just superior to the heart. 

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