NCLEX : Other General Biology

Study concepts, example questions & explanations for NCLEX

varsity tutors app store varsity tutors android store

Example Questions

Example Question #31 : General Biology

Which of the following is the main signaling molecule that acts on salivary acinar cells to increase production of saliva?

Possible Answers:

Serotonin

Epinephrine

Acetylcholine

Dopamine

Correct answer:

Acetylcholine

Explanation:

The primary signaling molecule that acts to increase saliva production by acinar cells in salivary glands is acetylcholine (ACh). ACh is released by parasympathetic innervation and triggers muscarinic receptors in salivary cells, leading to increased saliva secretion. While serotonin, epinephrine, and dopamine may have some effect on salivation, they are not the primary molecules through which the process is controlled. 

Example Question #31 : Gastrointestinal Physiology

In what part of the brain is the swallowing center located?

Possible Answers:

The medulla

The cerebellum

The thalamus

The cingulate gyrus

Correct answer:

The medulla

Explanation:

The swallowing center is not a specific anatomical structure, rather an area of physiological control. The swallowing reflex is primary controlled by the medulla, and to a lesser degree by the pons. None of the other structures listed play a significant role in deglutition. 

Example Question #32 : Gastrointestinal Physiology

Which of the following molecules is necessary for absorption of vitamin B12?

Possible Answers:

Serotonin

Sodium

Intrinsic factor

Norepinephrine

Correct answer:

Intrinsic factor

Explanation:

Dietary vitamin B12 must first form a complex with intrinsic factor, a gastric glycoprotein, before it can be absorbed into the hepatic portal system. Individuals who are unable to produce intrinsic factor are at risk for developing B12-related macrocytic anemia. While the other molecules listed are necessary for a wide variety of digestive and nervous system function, they do not directly control vitamin B12 absorption.

Example Question #33 : Gastrointestinal Physiology

Which of the following enzymes breaks down triglycerides in chylomicrons and very low-density lipoproteins (VLDL)?

Possible Answers:

Lingual lipase

Lipoprotein lipase

Hepatic lipase

Colipase

Correct answer:

Lipoprotein lipase

Explanation:

Lipoprotein lipase hydrolyzes triglycerides into two free fatty acids and one molecule of monoacylglycerol.

Hepatic lipase aids in the regeneration of LDL. Colipase is secreted by the pancreas and is an important co-enzyme for optimal function of pancreatic lipase. Lingual lipase is a fat-digesting enzyme that is secreted in the saliva and aids in the break down of dietary lipids before they are stored in chylomicron form. 

Example Question #31 : Gastrointestinal Physiology

All of the following large intestine bacteria are considered beneficial except __________.

Possible Answers:

Streptococcus thermophilus

Lactobaccilus plantarum

Clostridium difficile

Lactobacillus acidophilus

Correct answer:

Clostridium difficile

Explanation:

All of the bacterial strains listed have been shown to have beneficial effects on gut and immune health except for Clostridium difficile, a pathogenic bacteria commonly seen in hospital settings after prolonged antibiotic use. C. difficile has been associated with chronic diarrhea, behavioral disorders, and colitis.

Example Question #35 : Gastrointestinal Physiology

Where is intrinsic factor produced?

Possible Answers:

In the Brunner's glands of the duodenum

In the pancreas by beta islet cells

In the stomach by parietal cells

In the stomach by chief cells

Correct answer:

In the stomach by parietal cells

Explanation:

Intrinsic factor, a molecule necessary for the absorption of dietary B12, is produced by the parietal cells of the stomach. Its release stimulated by the same factors that stimulate release of hydrochloric acid: histamine, gastrin, and acetylcholine. 

Gastric chief cells secrete pepsinogen and chymosin, while beta islet cells of the pancreas secrete insulin. Brunner's glands secrete a mucus that protects th lining of the intestine.

Example Question #31 : General Biology

What percentage of resting cardiac output is filtering through the kidneys at any given moment?

Possible Answers:

20-25%

5-10%

10-15%

15-20%

Correct answer:

20-25%

Explanation:

The kidneys receive more blood flow than any single organ, after the liver. 20-25% of the cardiac output of the heart goes to the kidneys for filtration (the liver receives closer to 28%). This is especially significant considering that the kidneys account for approximately 0.5% of total body weight (while the liver makes up closer to 3% of total body weight). 

Example Question #32 : General Biology

What is the main functional unit of the kidney?

Possible Answers:

The nephron

The glomerulus

The Bowman's capsule

The loop of Henle

Correct answer:

The nephron

Explanation:

The basic functional unit of the kidney is the nephron. The nephron is composed of the glomerulus, which is encased in the Bowman's capsule, the proximal convoluted tubule, the loop of Henle, and distal convoluted tubule.

Example Question #33 : General Biology

99% of glucose and amino acids are resorbed in what part of the nephron?

Possible Answers:

The glomerulus

The loop of Henle

The distal tubule

The proximal tubule

Correct answer:

The proximal tubule

Explanation:

99% of glucose and amino acids are resorbed by the proximal tubule of the nephron. The loop of Henle and the distal tubule primarily resorb electrolytes and water, while the glomerulus is strictly for filtration and does not resorb solutes. 

Example Question #1 : Excretory Physiology

A nurse notes an elevated plasma creatinine in a patient with mild kidney impairment. How will this generally be reflected in the glomerular filtration rate (GFR)?

Possible Answers:

The GFR will be decreased

The GFR will not change

The GFR will be elevated

The GFR will rise, then decrease

Correct answer:

The GFR will be decreased

Explanation:

The GFR represents the rate at which blood is filtered through the glomeruli of the kidneys. Creatinine is a waste product of muscle metabolism. Healthy glomeruli are capable of filtering creatinine very effectively, wherein creatinine is excreted in the urine. Generally an elevated serum creatinine will be accompanied by a decreased glomerular filtration rate and is strongly predictive of kidney dysfunction. 

Learning Tools by Varsity Tutors