Nursing Elites

1. What is the valve that prevents blood from flowing back from the left ventricle into the left atrium?

• A. Tricuspid valve
• B. Mitral valve
• C. Aortic valve
• D. Pulmonic valve

Correct answer: B

Rationale: The correct answer is the Mitral valve. The mitral valve is located between the left atrium and the left ventricle of the heart. Its function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. Choice A, the Tricuspid valve, is incorrect as it is located between the right atrium and right ventricle. Choice C, the Aortic valve, and Choice D, the Pulmonic valve, are also incorrect as they are involved in the circulation of blood leaving the heart rather than preventing backflow within the atria and ventricles.

2. Which hormone primarily triggers ovulation in the female menstrual cycle?

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

Correct answer: C

Rationale: Luteinizing hormone (LH) is the hormone primarily responsible for triggering ovulation in the female menstrual cycle. LH surge occurs around the middle of the menstrual cycle, causing the mature follicle to release an egg from the ovary. Estrogen and progesterone play crucial roles in regulating the menstrual cycle and preparing the endometrium for potential implantation of a fertilized egg, but they do not trigger ovulation directly. Follicle-stimulating hormone (FSH) is essential for the development of ovarian follicles but is not the primary hormone responsible for ovulation. Therefore, the correct answer is Luteinizing hormone (LH) as it directly initiates the release of the egg during ovulation.

3. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

• A. 0.5 m/s²
• B. 1 m/s²
• C. 2 m/s²
• D. 10 m/s²

Correct answer: B

Rationale: The acceleration of an object is given by the formula \(a = \frac{F}{m}\), where \(F\) is the net force acting on the object and \(m\) is the mass of the object. In this case, the net force acting on the box is 20 N, and the mass of the box is 10 kg. Plugging these values into the formula, we get \(a = \frac{20}{10} = 2\) m/s².

4. Which of the following units is equivalent to a joule?

• A. Newton-meter (N·m)
• B. Watt (W)
• C. Kilogram (kg)
• D. Ampere (A)

Correct answer: A

Rationale: A joule is the SI unit of energy and work, defined as the work done by a force of one newton acting over a distance of one meter. Therefore, a joule is equivalent to a newton-meter (N·m), which represents the product of force (newton) and distance (meter). This unit reflects the energy transferred when a force of one newton moves an object one meter. Choice B, Watt (W), is the unit of power and is not equivalent to a joule. Choice C, Kilogram (kg), is a unit of mass. Choice D, Ampere (A), is the unit of electric current.

5. Which of the following structures can serve as a passageway for both food and air?

• A. Esophagus
• B. Laryngopharynx
• C. Nasopharynx
• D. Trachea

Correct answer: B

Rationale: The correct answer is the Laryngopharynx. It is a common passageway for both food and air. The Esophagus (Choice A) is solely for transporting food from the throat to the stomach. The Nasopharynx (Choice C) is primarily involved in the passage of air. The Trachea (Choice D) is responsible for conducting air to and from the lungs and does not play a role in the passage of food.

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