Nursing Elites

1. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: A

Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.

2. What potential consequences can chromosomal nondisjunction have on offspring?

• A. Down syndrome, caused by an extra copy of chromosome 21.
• B. Turner syndrome, characterized by the absence of one X chromosome in females.
• C. Klinefelter syndrome, featuring one or more extra X chromosomes in males.
• D. All of the above.

Correct answer: D

Rationale: - Chromosomal nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division, leading to an abnormal number of chromosomes in the resulting cells. - Down syndrome is caused by an extra copy of chromosome 21, resulting from nondisjunction during meiosis. Individuals with Down syndrome have three copies of chromosome 21 instead of the usual two. - Turner syndrome is characterized by the absence of one X chromosome in females, leading to a variety of physical and developmental features. - Klinefelter syndrome features one or more extra X chromosomes in males, typically resulting in infertility and other physical characteristics. Therefore, chromosomal nondisjunction can lead to various genetic disorders such as Down syndrome, Turner syndrome, and Klinefelter syndrome, making option D the correct answer.

3. Which property of a substance measures the amount of matter per unit volume?

• A. Density
• B. Mass
• C. Weight
• D. Volume

Correct answer: A

Rationale: Density is the property of a substance that measures the amount of matter per unit volume. It is calculated by dividing the mass of the substance by its volume. Mass refers to the amount of matter in an object, weight is the force of gravity acting on an object, and volume is the amount of space an object occupies. Density specifically quantifies how tightly packed the matter in a substance is, providing a measure of compactness or concentration of matter. Therefore, the correct answer is A, Density.

4. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: Calcitonin is a hormone produced by the thyroid gland that primarily functions to lower blood calcium levels. It achieves this by inhibiting bone breakdown and promoting calcium excretion by the kidneys. Therefore, the correct answer is D as it reflects the main role of calcitonin in calcium homeostasis. Choices A, B, and C are incorrect as they do not align with the primary function of calcitonin. Calcitonin does not stimulate metabolism and heat production (Choice A), increase calcium absorption from the intestines (Choice B), or enhance bone growth and development (Choice C).

5. What does antidiuretic hormone (ADH) help the kidneys regulate?

• A. Acid-base balance
• B. Blood pressure
• C. Urine output by controlling water reabsorption
• D. All of the above

Correct answer: C

Rationale: Antidiuretic hormone (ADH) helps the kidneys regulate urine output by controlling water reabsorption. ADH acts on the kidneys to increase the reabsorption of water, leading to a decrease in urine output. This helps the body conserve water and maintain proper fluid balance. ADH primarily affects urine output by controlling water reabsorption and does not directly regulate acid-base balance or blood pressure. Therefore, choices A and B are incorrect because ADH does not directly influence acid-base balance or blood pressure.

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