NCLEX : General Biology

Study concepts, example questions & explanations for NCLEX

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Example Questions

Example Question #271 : General Biology

Catecholamines are hormones that are released into the blood in response to stress. Where in the body are catecholamines produced? 

Possible Answers:

The adrenal cortex

The adrenal medulla

The thyroid gland

The parathyroid gland

The anterior pituitary gland

Correct answer:

The adrenal medulla

Explanation:

Catecholamines are hormones produced by the adrenal medulla. Adrenal glands are located above each kidney. Catecholamines may also function as neurotransmitters, important chemical messengers. They regulate the sympathetic nervous system's response to stress.

Example Question #272 : General Biology

The pancreas produces many hormones that are vital to body function. Which of the following is not produced by the pancreas? 

Possible Answers:

Glucagon

Lipase

Somatostatin

Insulin

Calcitonin

Correct answer:

Calcitonin

Explanation:

Calcitonin is produced by the thyroid gland. The hormone plays an important role in lowering blood calcium levels. It is also synthesized as a drug and used in the treatment of hypercalcemia. The other three hormones are indeed secreted by the islets of Langerhans in the pancreas. Insulin, secreted by the beta cells lowers blood sugar, glucagon, secreted by the alpha cells, increases blood sugar, and somatostatin, secreted by the gamma cells regulates digestive and metabolic processes. Lipase is not a hormone, but an enzyme that facilitates the breakdown of lipids. The pancreas does indeed secrete lipase.

Example Question #15 : Hormones

Which of the following regarding the thyroid gland is false? 

Possible Answers:

The thyroid gland is located posterior to the trachea

Calcitonin is released by the thyroid

The thyroid releases hormones in response to hormones secreted by the anterior pituitary

T3 is more potent than T4

The thyroid gland produces more T4 than T3

Correct answer:

The thyroid gland is located posterior to the trachea

Explanation:

The thyroid gland is located (in front) anterior to the trachea. The parathyroid glands are located on the backside on the thyroid. The thyroid is stimulated in response to TSH produced by the anterior pituitary. It will then secrete T3 and T4 although T3 is more potent and produced in a lesser quantity. Calcitonin, a hormone which decreases blood calcium levels, is also produced by the thyroid.

Example Question #16 : Hormones

Which of the following hormones causes a feeling of satiety?

Possible Answers:

Leptin

Insulin

Cortisol

Growth hormone

Correct answer:

Leptin

Explanation:

Leptin is secreted by adipose cells, and acts on the arcuate nucleus of the lateral hypothalamus to promote the synthesis of alpha-MSH (alpha-melanocyte-stimulating hormone), which is a hunger suppressant. It also binds to receptors for neuropeptide Y (NPY), a powerful hunger promoter, in the arcuate nucleus. 

None of the other hormones listed, while all involved in nutrient and blood sugar metabolism, directly trigger feeling of satiety.

Example Question #17 : Endocrine And Immune Systems

Which of the following will cause a decrease in leptin levels?

Possible Answers:

Sleep deprivation

Exercise

All of these are correct

High testosterone

Correct answer:

All of these are correct

Explanation:

Leptin, the hormone responsible for feelings of satiety, goes down during times of fasting, with high testosterone, during sleep deprivation, and during periods of prolonged exercise or physical training.

Example Question #581 : Nclex

Which of the following is not an effect of insulin?

Possible Answers:

Triggers lipolysis

Increases protein synthesis

Increases uptake of potassium ions

Increases glycogen synthesis

Correct answer:

Triggers lipolysis

Explanation:

Insulin has many physiological effects on metabolism. It increases uptake of glucose and various ions, especially potassium, from the blood. It promotes glycogen and protein synthesis, and encourages storage of fats. Conversely, insulin inhibits lipolysis, gluconeogenesis, ketogenesis, and proteolysis.

Example Question #582 : Nclex

Which of the following is the primary immunoglobulin secreted into the intestinal lining and mucus membranes of the respiratory tract?

Possible Answers:

IgE

IgA

IgG

IgM

Correct answer:

IgA

Explanation:

IgA, primarily in its secretory form (sIgA), is the most abundant immunoglobulin in the lining of the gastrointestinal tract and in the mucus membranes of the respiratory tract. It is also present in the urogenital tract, in tears, in saliva, and in breast milk. All of the other immunoglobulins may be present in mucus membranes, depending on the presence of active infection or allergy, but none is as abundant in secretions as IgA. IgE is primarily involved in binding allergens and inducing the allergic response via release of histamine. IgM is expressed on the surface of B cells and is the first immunoglobulin to fight pathogens at the site of infection/injury. IgG are the most abundant antibody throughout the body and play the largest role in fighting pathogens. IgG can cross the placenta and thus confer passive immunity to the fetus. 

Example Question #583 : Nclex

The presence of which of the following cytomegalovirus (CMV) antibodies would suggest an active CMV infection?

Possible Answers:

CMV IgD

CMV IgG

CMV IgE

CMV IgM

Correct answer:

CMV IgM

Explanation:

The presence of CMV IgM would suggest an active cytomegalovirus infection, as IgM is the immunoglobulin released during the initial, active infection with a pathogen. The presence of IgG would suggest a past infection, where IgG specific to the virus would be present as part of adaptive immunity (ready to respond to the virus should the host ever be re-exposed). IgE is not formed when an individual contracts CMV, as IgE is produced in response to allergens rather than pathogens (except parasites). The function of IgD is thought to be related to the allergic response by regulating basophils and mast cells.

Example Question #581 : Nclex

Which of the following is the only immunoglobulin capable of crossing the placenta and conferring passive immunity to a fetus?

Possible Answers:

IgG

IgE

IgM

IgA

Correct answer:

IgG

Explanation:

The only immunoglobulin that has been shown to be able to cross the placenta is IgG. This is important in that it confers short term immunity to the fetus that continues into the first few months of the infant's life. Note that it is common to give Rh-negative anti-Rh IgG injections at about 28 weeks gestation; a booster may also be given at about 34 weeks gestation.

Example Question #581 : Nclex

Which cells of the pancreas produce insulin?

Possible Answers:

Beta cells

Gamma cells

Alpha cells

Delta cells

Correct answer:

Beta cells

Explanation:

Insulin is produced by beta cells of the pancreatic islets. Insulin's action is to decrease blood glucose, facilitating its uptake into cells. Alpha cells produce glucagon, which has the opposite effect as insulin. Delta cells produce somatostatin, which inhibits many digestive processes. and gamma cells produce pancreatic polypeptide, which regulate pancreatic secretion. 

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