Nursing Elites

1. Which of the following is an example of a weak acid?

• A. Hydrochloric acid (HCl)
• B. Sulfuric acid (H2SO4)
• C. Acetic acid (CH3COOH)
• D. Nitric acid (HNO3)

Correct answer: C

Rationale: Weak acids only partially dissociate in water, releasing a lower concentration of hydrogen ions.

2. Vaccines work by stimulating the immune system to develop:

• A. A physical barrier against pathogens
• B. An inflammatory response
• C. Immunological memory to a specific pathogen
• D. Phagocytes to engulf pathogens

Correct answer: C

Rationale: The correct answer is C: 'Immunological memory to a specific pathogen.' Vaccines work by introducing a harmless form of a pathogen or a piece of it to stimulate the immune system. This exposure triggers the production of antibodies and memory cells specific to that pathogen. These memory cells 'remember' the pathogen, allowing the immune system to respond more effectively and rapidly if exposed to the actual pathogen in the future. Options A, B, and D are incorrect because vaccines do not create a physical barrier, induce a general inflammatory response, or directly cause phagocytes to engulf pathogens; instead, vaccines enhance the immune system's ability to recognize and combat specific pathogens.

3. Which element makes up the majority of the Earth's atmosphere?

• A. Nitrogen
• B. Oxygen
• C. Carbon dioxide
• D. Argon

Correct answer: A

Rationale: Nitrogen is the most abundant gas in the Earth's atmosphere, crucial for plant life and maintaining the planet's temperature balance.

4. Which blood vessels carry oxygenated blood from the heart to the rest of the body?

• A. Pulmonary arteries
• B. Pulmonary veins
• C. Systemic arteries
• D. Systemic veins

Correct answer: C

Rationale: The correct answer is C: Systemic arteries. Systemic arteries carry oxygenated blood from the heart to the rest of the body, delivering vital nutrients and oxygen to tissues and organs. Pulmonary arteries carry deoxygenated blood from the heart to the lungs for oxygenation. Pulmonary veins carry oxygenated blood from the lungs back to the heart. Systemic veins return deoxygenated blood from the body to the heart. It's important to differentiate between pulmonary and systemic vessels in understanding the circulation of blood throughout the body.

5. Which vitamin is crucial for calcium absorption and synthesized in the skin upon sun exposure?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin E

Correct answer: C

Rationale: The correct answer is C: Vitamin D. Vitamin D is crucial for calcium absorption as it helps the body absorb calcium from the diet. When the skin is exposed to sunlight, it produces vitamin D. This is why sunlight is often referred to as the 'sunshine vitamin.' Vitamin A (choice A) is important for vision and immune function, but not specifically for calcium absorption. Vitamin C (choice B) is essential for collagen production and immune function, but not directly related to calcium absorption. Vitamin E (choice D) is an antioxidant that helps protect cells from damage, but it is not primarily involved in calcium absorption like vitamin D.

6. Which neurotransmitter is associated with pleasure, reward, and motivation, and is often implicated in conditions such as addiction?

• A. Acetylcholine
• B. Dopamine
• C. Serotonin
• D. GABA (Gamma-aminobutyric acid)

Correct answer: b

Rationale: The correct answer is B: Dopamine. Dopamine is a neurotransmitter that is commonly associated with pleasure, reward, and motivation. It plays a crucial role in the brain's reward system and is often implicated in conditions such as addiction. Dopamine is released in response to rewarding stimuli, reinforcing behaviors that lead to pleasure. Acetylcholine is involved in muscle contraction and memory, not pleasure and reward. Serotonin is known for regulating mood and emotions, while GABA is an inhibitory neurotransmitter that helps reduce neural activity. Therefore, dopamine is the neurotransmitter most closely linked to pleasure, reward, and motivation in the brain.

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