Nursing Elites

1. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

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. Which cavity contains all of the frontal cavities? Choose only ONE best answer.

• A. Dorsal
• B. Thoracic
• C. Abdominopelvic
• D. Ventral

Correct answer: D

Rationale: The correct answer is D: Ventral. The ventral cavity includes both the thoracic and abdominopelvic cavities. The frontal cavities are part of the ventral cavity, which is located towards the front of the body, while the dorsal cavity is towards the back. The dorsal cavity contains the cranial and vertebral cavities, not the frontal cavities. The thoracic cavity is part of the ventral cavity but does not encompass all the frontal cavities. The abdominopelvic cavity is also part of the ventral cavity, but it does not include all of the frontal cavities. Therefore, the ventral cavity is the correct choice as it encompasses all the frontal cavities.

4. What term describes the bouncing back of waves after striking a surface or boundary?

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

Correct answer: C

Rationale: The correct answer is 'Reflection.' Reflection is the term used to describe the bouncing back of waves after striking a surface or boundary. Diffraction, on the other hand, refers to the bending of waves around obstacles. Refraction is the bending of waves as they pass from one medium to another. Interference involves the combination of two or more waves that results in a new wave pattern. Therefore, in this context, choices A, B, and D are incorrect as they do not specifically relate to the bouncing back of waves after striking a surface or boundary.

5. Which term describes the ability of a substance to conduct electricity?

• A. Reactivity
• B. Density
• C. Conductivity
• D. Viscosity

Correct answer: C

Rationale: Conductivity is the correct term used to describe the ability of a substance to conduct electricity. Reactivity is the measure of a substance's tendency to undergo chemical reactions. Density refers to the mass per unit volume of a substance, while viscosity is a measure of a fluid's resistance to flow. In the context of conducting electricity, conductivity is the most appropriate term as it directly relates to the substance's electrical conductive properties.

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