Nursing Elites

1. Which of the following best describes eosinophils?

• A. A type of granulocyte that secretes histamine to stimulate the inflammatory response.
• B. The most abundant type of white blood cell that secretes substances toxic to pathogens.
• C. A type of granulocyte found under mucous membranes that defends against multicellular parasites.
• D. A circulating granulocyte with high phagocytic activity and aggressiveness.

Correct answer: C

Rationale: Eosinophils are best described as a type of granulocyte found under mucous membranes that defends against multicellular parasites. They release toxic substances to combat parasitic infections and play a significant role in allergic reactions and asthma. Histamine secretion to stimulate inflammation is more characteristic of basophils, while high phagocytic activity and aggressiveness are features of neutrophils, not eosinophils. Describing eosinophils as the most abundant type of white blood cell that secretes toxic substances to pathogens is inaccurate since eosinophils specifically target multicellular parasites, not a broad range of pathogens.

2. What is the formula to calculate work?

• A. Work = Force × Distance
• B. Work = Mass × Velocity
• C. Work = Power × Time
• D. Work = Energy ÷ Time

Correct answer: A

Rationale: Work is defined as the product of the force applied to an object and the distance over which the force is applied. The formula to calculate work is represented by Work = Force × Distance, where force is the applied force on an object and distance is the displacement over which the force is applied. Therefore, the correct formula to calculate work is Work = Force × Distance. Choice B, 'Work = Mass × Velocity,' is incorrect because work involves force and distance, not mass and velocity. Choice C, 'Work = Power × Time,' is incorrect because work is not directly calculated using power and time. Choice D, 'Work = Energy ÷ Time,' is incorrect because work is not typically calculated by dividing energy by time; rather, it involves the product of force and distance.

3. What is the primary function of coronary arteries?

• A. Delivering oxygenated blood throughout the body.
• B. Supplying oxygenated blood to the heart muscle itself.
• C. Carrying deoxygenated blood back to the heart.
• D. Regulating blood pressure through vasoconstriction and vasodilation.

Correct answer: B

Rationale: The primary function of coronary arteries is to supply oxygenated blood to the heart muscle itself. The heart is a muscle that needs a constant supply of oxygen and nutrients to function properly. Coronary arteries branch off the aorta and specifically deliver oxygenated blood to the heart muscle, ensuring its proper function. Choice A is incorrect because coronary arteries do not deliver blood throughout the entire body but specifically to the heart. Choice C is incorrect as coronary arteries carry oxygenated blood away from the heart. Choice D is incorrect as the primary function of the coronary arteries is not to regulate blood pressure but rather to provide oxygenated blood to the heart muscle.

4. Which valve prevents the return of blood into the right ventricle?

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

Correct answer: A

Rationale: The correct answer is A: Pulmonary semilunar valve. The pulmonary semilunar valve is located between the right ventricle and the pulmonary artery. It opens to allow blood to be pumped into the pulmonary artery but closes to prevent blood from returning back into the right ventricle. The aortic semilunar valve is located between the left ventricle and the aorta. The tricuspid valve is located between the right atrium and right ventricle, and the mitral valve is located between the left atrium and left ventricle. Therefore, the pulmonary semilunar valve is the specific valve responsible for preventing the backflow of blood into the right ventricle during the cardiac cycle.

5. What substance is required to drive the sliding filament process during muscle contraction?

• A. ATP
• B. Hormone
• C. Potassium
• D. Water

Correct answer: A

Rationale: The substance required to drive the sliding filament process during muscle contraction is ATP (adenosine triphosphate). ATP provides the energy needed for muscle contraction by enabling the myosin heads to bind to actin and generate force. This energy release drives the sliding of the filaments, causing muscle fibers to contract. Hormones, potassium, and water do not directly drive the sliding filament process in muscle contraction. Hormones are signaling molecules that regulate various physiological processes but do not directly provide energy for muscle contraction. Potassium is an electrolyte important for nerve and muscle function but is not the primary driver of the sliding filament process. Water is essential for overall hydration and bodily functions but does not directly participate in the muscle contraction process.

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