Nursing Elites

1. What phenomenon explains the bending of light as it passes around an obstacle or through an aperture?

• A. Refraction
• B. Reflection
• C. Diffraction
• D. Dispersion

Correct answer: c

Rationale: Diffraction refers to the bending of light waves as they encounter an obstacle or pass through an aperture, causing the light to spread out.

2. A satellite orbits the Earth at constant speed. Which force is responsible for its circular motion?

• A. Gravitational force from the Earth
• B. Thrust from the satellite's engine
• C. Friction between the satellite and the atmosphere
• D. Normal force from the Earth's surface

Correct answer: A

Rationale: This force acts towards the Earth's center, providing the centripetal force required for the satellite to move in a circle.

3. Which part of the heart generates the QRS complex on an ECG?

• A. Sinoatrial node (SA node)
• B. Atrioventricular node (AV node)
• C. Bundle of His
• D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

4. Which of the following structures is responsible for preventing the backflow of blood from the left ventricle into the left atrium?

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

Correct answer: D

Rationale: The correct answer is D, the mitral valve. The mitral valve, also known as the bicuspid valve, is located between the left atrium and the left ventricle. Its main function is to prevent the backflow of blood from the left ventricle into the left atrium during ventricular contraction. The aortic valve (A) is responsible for preventing the backflow of blood from the aorta into the left ventricle, the pulmonary valve (B) prevents backflow from the pulmonary artery into the right ventricle, and the tricuspid valve (C) prevents backflow from the right ventricle into the right atrium. Therefore, the mitral valve is specifically responsible for preventing backflow in the left side of the heart, making it the correct answer in this case.

5. During sexual intercourse, sperm travels through a tube from the testes to the urethra. What is the name of this tube?

• A. Vas deferens
• B. Epididymis
• C. Seminal vesicle
• D. Urethra

Correct answer: A

Rationale: The correct answer is A: 'Vas deferens.' The vas deferens is a tube that carries sperm from the testes to the urethra during ejaculation. It is a crucial part of the male reproductive system, allowing for the transport of sperm for fertilization. The epididymis is where sperm mature and are stored, not where they travel during intercourse. The seminal vesicle is a gland that produces a significant portion of the seminal fluid. The urethra is the tube that carries both urine and semen out of the body but is not where sperm travels from the testes.

6. 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.

Similar Questions