Nursing Elites

1. Positive feedback mechanisms usually result in

• A. changes returning values away from a set point.
• B. stable conditions around a set point.
• C. unstable conditions.
• D. long-term changes.

Correct answer: C

Rationale: Positive feedback mechanisms usually result in unstable conditions. In a positive feedback loop, the output enhances or amplifies the changes that are occurring, leading to a deviation from the initial set point. Therefore, positive feedback does not bring values back towards the set point (Choice A). Choice B is incorrect because positive feedback does not promote stability around a set point. Choice D is also incorrect as positive feedback mechanisms typically do not lead to long-term changes; instead, they intensify the initial change, causing instability.

2. Which part of the brain regulates heart rate, respiratory rate, and blood pressure?

• A. Corpus Callosum
• B. Medulla Oblongata
• C. Pituitary Glands
• D. Pineal Glands

Correct answer: B

Rationale: The correct answer is the Medulla Oblongata. This part of the brain is responsible for regulating essential autonomic functions such as heart rate, respiratory rate, and blood pressure. The Corpus Callosum is responsible for connecting the left and right hemispheres of the brain, not for regulating these vital functions. The Pituitary Glands and Pineal Glands are part of the endocrine system and are not directly involved in regulating heart rate, respiratory rate, and blood pressure.

3. Which of the following is not an example of a homeostatic mechanism in the human body?

• A. Shivering when the body temperature falls below normal.
• B. Increasing heart rate and force of contraction when blood pressure falls.
• C. Retaining fluid excessively.
• D. Secreting insulin after a meal to return blood sugar concentration toward normal.

Correct answer: C

Rationale: The correct answer is C. Homeostatic mechanisms aim to maintain internal stability within the body. Choices A, B, and D all represent examples of homeostatic mechanisms. Shivering helps generate heat to raise body temperature back to normal levels. Increasing heart rate and force of contraction work to restore blood pressure. Insulin secretion after a meal helps regulate blood sugar levels. On the other hand, retaining fluid excessively can lead to fluid imbalance rather than maintaining internal stability, making it the incorrect choice.

4. Organ systems consist of organs, which consist of tissues.

• A. True
• B. False
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: The statement is true. Organ systems are made up of organs, which in turn are composed of tissues. Organs are structures made up of two or more types of tissues that work together to perform specific functions. Tissues, on the other hand, are groups of cells that work together to perform a specific function. Therefore, organs are made up of tissues, and organ systems consist of organs.

5. An obstetrician tells a 42-year-old patient that she can have a healthy baby, but that she is of 'advanced maternal age.' The patient is so upset that she fails to listen to the rest of the doctor's advice, goes home in a huff, and immediately dyes her hair.

• A. the age of the sperm.
• B. the age of her eggs.
• C. her risk of developing diabetes.
• D. her cholesterol level, not her appearance.

Correct answer: B

Rationale: The correct answer is 'the age of her eggs.' As women age, the quality of their eggs decreases, leading to a higher risk of chromosomal abnormalities and infertility. This decline in egg quality is why advanced maternal age is associated with a higher risk of certain pregnancy complications. Choices A, C, and D are incorrect because the primary concern in this context is related to the age-related changes in a woman's eggs, not sperm, diabetes risk, or cholesterol levels.

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