Nursing Elites

1. What defines the systole phase in the cardiac cycle?

• A. Relaxation of the heart
• B. Contraction of the heart
• C. Diastole of the heart
• D. Pulse rate of the heart

Correct answer: B

Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.

2. How many grams of solid CaCO3 are needed to make 600 mL of a 35 M solution? The atomic masses for the elements are as follows: Ca = 40.1 g/mol; C = 12.01 g/mol; O = 16.00 g/mol.

• A. 18.3 g
• B. 19.7 g
• C. 21.0 g
• D. 24.2 g

Correct answer: B

Rationale: 1. First, calculate the molar mass of CaCO3 by adding the atomic masses of Ca, C, and 3 O atoms: 40.1 + 12.01 + (3 * 16.00) = 100.13 g/mol. 2. Calculate the number of moles in 600 mL of a 35 M solution: 600 mL * 35 mol/L = 21,000 mmol. 3. Convert moles to grams using the molar mass of CaCO3: 21,000 mmol * (100.13 g/mol / 1000 mmol/mol) = 2,102.73 g. 4. Therefore, you would need 19.7 g of solid CaCO3 to make 600 mL of a 35 M solution.

3. Convert 3,450 grams to milligrams (mg).

• A. 34,500 mg
• B. 3,450,000 mg
• C. 3,450 mg
• D. 3,450,000 mg

Correct answer: B

Rationale: To convert grams to milligrams, you need to multiply by 1,000 since there are 1,000 milligrams in a gram. Therefore, 3,450 grams × 1,000 = 3,450,000 milligrams. Choice A (34,500 mg) is incorrect because it represents the result for converting grams to milligrams by a factor of 10 (not 1,000). Choice C (3,450 mg) is incorrect as it represents the original amount in grams, not the converted amount to milligrams. Choice D (3,450,000 mg) is incorrect as it is the same as the correct answer but with the comma in the wrong place, which would imply converting kilograms to milligrams rather than grams to milligrams.

4. Which of the following is NOT a function of the cilia lining the respiratory tract?

• A. Trapping inhaled dust and debris
• B. Moistening inhaled air
• C. Producing mucus
• D. Propelling mucus upwards towards the throat

Correct answer: B

Rationale: The correct answer is B: Moistening inhaled air. The cilia lining the respiratory tract primarily function to trap inhaled dust and debris, produce mucus, and propel the mucus upwards towards the throat for removal. Moistening inhaled air is primarily done by the mucous membranes in the nasal passages, which contain blood vessels that help warm and humidify the air as it passes through the nasal cavity. Therefore, the function of moistening inhaled air is not directly associated with the cilia in the respiratory tract, making it the correct choice in this scenario. Choices A, C, and D are incorrect as they are all functions carried out by the cilia in the respiratory tract.

5. What is the role of the kidneys in the body?

• A. To regulate body temperature
• B. To filter waste from the blood
• C. To produce hormones
• D. To transport oxygen

Correct answer: B

Rationale: The correct answer is B: To filter waste from the blood. The kidneys play a crucial role in filtering waste products and excess substances from the blood to form urine, which helps maintain fluid balance and eliminate toxins from the body. Choice A is incorrect because regulating body temperature is primarily controlled by the skin and other mechanisms. Choice C is incorrect as hormone production is mainly attributed to other organs like the endocrine glands. Choice D is incorrect as the transportation of oxygen is primarily facilitated by the lungs and circulatory system, not the kidneys.

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