Nursing Elites

1. Half-life refers to the characteristic time it takes for:

• A. Radioactive intensity to completely disappear
• B. The number of neutrons in a nucleus to double
• C. The number of protons in a nucleus to change
• D. An isotope to decay by half of its initial quantity

Correct answer: D

Rationale: The correct answer is D: An isotope to decay by half of its initial quantity. The half-life of a substance is the time it takes for half of the initial quantity of radioactive atoms to decay. This is a characteristic property of each radioactive isotope and is used to determine the rate of decay of a substance. Option A is incorrect because radioactive intensity does not completely disappear in half-life, it only decreases by half. Options B and C are unrelated to the concept of half-life and do not accurately describe its definition.

2. What is the primary function of the epiglottis in the respiratory system?

• A. Filtration of air
• B. Production of mucus
• C. Prevention of food entering the trachea
• D. Oxygen exchange in the alveoli

Correct answer: C

Rationale: The primary function of the epiglottis in the respiratory system is to prevent food from entering the trachea. When we swallow, the epiglottis covers the opening to the trachea, directing food and liquids to the esophagus instead of the airway. This action helps to protect the respiratory system from foreign objects that could obstruct airflow and cause choking or aspiration pneumonia. Filtration of air and production of mucus are functions associated with other respiratory structures like the nasal passages and bronchial tubes, while oxygen exchange in the alveoli occurs in the lungs, not the epiglottis.

3. Which of the following terms refers to the abnormal sound heard during a stethoscope examination, potentially indicating a heart valve issue?

• A. Tachycardia
• B. Bradycardia
• C. Heart murmur
• D. Arrhythmia

Correct answer: D

Rationale: The correct answer is D: Arrhythmia. An arrhythmia refers to an irregular heart rhythm, which can manifest as abnormal sounds heard during a stethoscope examination. Tachycardia (A) and bradycardia (B) both pertain to heart rate abnormalities, with tachycardia indicating a fast heart rate and bradycardia a slow heart rate. However, these terms do not specifically relate to abnormal sounds. Heart murmur (C) is the term that refers to the abnormal sound heard during a stethoscope examination, potentially indicating a heart valve issue. Therefore, the correct answer is D as it best fits the description provided in the question.

4. Which hormone is responsible for the characteristic changes experienced during puberty, such as breast development and menstruation in females?

• A. Follicle-stimulating hormone (FSH)
• B. Luteinizing hormone (LH)
• C. Estrogen
• D. Progesterone

Correct answer: C

Rationale: The correct answer is C: Estrogen. Estrogen plays a crucial role in regulating the development of secondary sexual characteristics during puberty in females. It is responsible for breast development, widening of hips, and the onset of menstruation. Estrogen is mainly produced by the ovaries and is essential for the maturation of the reproductive system. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are pituitary hormones that regulate the menstrual cycle and ovulation but do not directly cause the characteristic changes seen during puberty. Progesterone is another hormone involved in the menstrual cycle and pregnancy but is not primarily responsible for the physical changes during puberty.

5. A solution is 60% alcohol. If 200ml of the solution are used, how much pure alcohol is present?

• A. 100ml
• B. 120ml
• C. 140ml
• D. 160ml

Correct answer: C

Rationale: Multiply the total solution volume (200ml) by the alcohol percentage (60%)

6. Which hormone, produced by the pineal gland, plays a role in regulating sleep-wake cycles and is often associated with the body's internal circadian rhythm?

• A. Melatonin
• B. Serotonin
• C. Dopamine
• D. Endorphin

Correct answer: a

Rationale: The correct answer is A: Melatonin. Melatonin is a hormone produced by the pineal gland that plays a crucial role in regulating sleep-wake cycles and is closely tied to the body's circadian rhythm. It is often referred to as the 'sleep hormone' because it helps signal to the body when it is time to sleep and wake up. Serotonin (option B) is a neurotransmitter that plays a role in mood regulation and happiness. Dopamine (option C) is involved in reward-motivated behavior and movement. Endorphins (option D) are neuropeptides that act as natural painkillers and contribute to feelings of pleasure. Therefore, Melatonin is the hormone associated with the body's internal circadian rhythm and sleep-wake cycles.

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