Nursing Elites

1. How do killer T cells recognize infected cells?

• A. The B cells flag the infected cells with amino acids.
• B. Tiny bits of the virus's RNA are left around the cell.
• C. Macrophages show up to help consume the infected cell.
• D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

2. What is the first number in a blood pressure reading?

• A. Diastolic pressure
• B. Mean arterial pressure
• C. Pulse rate
• D. Systolic pressure

Correct answer: D

Rationale: The correct answer is D: Systolic pressure. In a blood pressure reading, the first number represents the systolic pressure, which is the maximum pressure in the arteries during heart contraction. The second number in the reading is the diastolic pressure, which indicates the pressure in the arteries when the heart is at rest. Choices A, B, and C are incorrect because diastolic pressure, mean arterial pressure, and pulse rate are not the first numbers in a blood pressure reading.

3. Which term describes the ability of a substance to conduct electricity?

• A. Reactivity
• B. Density
• C. Conductivity
• D. Viscosity

Correct answer: C

Rationale: Conductivity is the correct term used to describe the ability of a substance to conduct electricity. Reactivity is the measure of a substance's tendency to undergo chemical reactions. Density refers to the mass per unit volume of a substance, while viscosity is a measure of a fluid's resistance to flow. In the context of conducting electricity, conductivity is the most appropriate term as it directly relates to the substance's electrical conductive properties.

4. What is the scientific unit used to measure the radioactivity of a substance?

• A. Becquerel (Bq)
• B. Joule (J)
• C. Newton (N)
• D. Kelvin (K)

Correct answer: A

Rationale: The correct answer is A: Becquerel (Bq). The Becquerel (Bq) is the scientific unit used to measure the radioactivity of a substance. It is named after Henri Becquerel, who discovered radioactivity. The Joule (J) is the unit of energy, Newton (N) is the unit of force, and Kelvin (K) is the unit of temperature. When measuring radioactivity, the Becquerel is used to quantify the rate of radioactive decay in a substance. Choices B, C, and D are incorrect as they represent units for energy, force, and temperature, respectively, not radioactivity.

5. What causes varicose veins to occur?

• A. Atherosclerosis.
• B. Incompetent valves.
• C. Loss of skin turgor.
• D. Loss of blood vessel elasticity.

Correct answer: B

Rationale: Varicose veins occur when the valves within the veins become incompetent, leading to blood pooling in the veins instead of being efficiently pumped back to the heart. This causes the veins to become enlarged, twisted, and visible under the skin. Factors such as genetics, aging, pregnancy, and prolonged standing or sitting can contribute to the development of incompetent valves and the resulting varicose veins. Atherosclerosis is the buildup of plaque in arteries, not veins, and does not directly cause varicose veins. Loss of skin turgor is related to skin elasticity and not a direct cause of varicose veins. Loss of blood vessel elasticity is a general term and does not specifically address the mechanism behind varicose veins, which is primarily due to incompetent valves.

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