Nursing Elites

1. What is the primary function of the immune system?

• A. To transport oxygen
• B. To fight infections
• C. To produce energy
• D. To regulate body temperature

Correct answer: B

Rationale: The primary function of the immune system is to fight infections. It identifies and destroys pathogens like bacteria and viruses, protecting the body from harmful substances. While oxygen transportation is carried out by the respiratory system, energy production is mainly the role of the metabolic system, and body temperature regulation is managed by the thermoregulatory system. These functions are separate from the immune system's primary role of defending the body against infections.

2. What is the primary function of the kidneys in the urinary system?

• A. Regulating blood pressure
• B. Filtering blood to remove waste
• C. Producing red blood cells
• D. Regulating electrolyte balance

Correct answer: B

Rationale: The primary function of the kidneys in the urinary system is to filter blood to remove waste products and excess fluids, which are then excreted as urine. Kidneys act as a filtration system, removing waste like urea, excess salts, and toxins. While the kidneys do play a role in regulating blood pressure by secreting renin and maintaining electrolyte balance by adjusting the levels of sodium, potassium, and other ions in the blood, their main and essential function is filtration and waste removal, making choice B the correct answer.

3. Which of the heart's four chambers is the largest and the strongest?

• A. Left ventricle
• B. Left atrium
• C. Right ventricle
• D. Right atrium

Correct answer: A

Rationale: The correct answer is the left ventricle. The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the entire body, making it a vital component of the circulatory system. The left atrium receives oxygen-rich blood from the lungs, the right ventricle pumps deoxygenated blood to the lungs for oxygenation, and the right atrium receives deoxygenated blood from the body.

4. Which gland produces the hormone melatonin?

• A. Pineal gland
• B. Thyroid gland
• C. Pituitary gland
• D. Adrenal gland

Correct answer: A

Rationale: The correct answer is the Pineal gland. The pineal gland is responsible for producing melatonin, a hormone that helps regulate the sleep-wake cycle. Melatonin secretion is influenced by light exposure. Higher levels are observed at night to promote sleep, while lower levels during the day encourage wakefulness. Choices B, C, and D are incorrect as they are not associated with the production of melatonin. The thyroid gland produces hormones like thyroxine and triiodothyronine, the pituitary gland controls various other glands, and the adrenal gland produces hormones like adrenaline and cortisol.

5. Which of the following statements best describes endocrine glands?

• A. They secrete chemicals into the blood
• B. They secrete enzymes into ducts
• C. They produce sweat
• D. They produce saliva

Correct answer: A

Rationale: Endocrine glands are ductless glands that release hormones directly into the bloodstream. These hormones are then carried to target organs and tissues throughout the body, where they regulate various physiological functions. The statement 'They secrete chemicals into the blood' accurately describes the function of endocrine glands. Choices B, C, and D are incorrect because endocrine glands do not secrete enzymes into ducts, produce sweat, or produce saliva. These functions are typically associated with exocrine glands, sweat glands, and salivary glands, respectively.

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