Nursing Elites

1. When is a solution formed?

• A. One substance dissolves in another
• B. Two or more substances react chemically
• C. A solid changes to a liquid
• D. None of the above

Correct answer: A

Rationale: A solution is formed when one substance dissolves in another. This process creates a homogeneous mixture where the solute is dispersed in the solvent, resulting in a uniform composition throughout the mixture. Choice B is incorrect because chemical reactions involve the transformation of substances into new compounds, not the formation of solutions. Choice C is incorrect as it describes a physical change from a solid to a liquid, not the formation of a solution. Choice D is incorrect as one substance dissolving in another is the defining characteristic of a solution.

2. What term refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction?

• A. Sarcomere
• B. Synapse
• C. Tendon
• D. Myofibril

Correct answer: B

Rationale: The correct answer is B, 'Synapse.' The synapse is the specific term that refers to the point of contact between a motor neuron and a muscle fiber, where communication occurs to initiate muscle contraction. At the synapse, neurotransmitters are released by the motor neuron, triggering the muscle fiber to contract. Choice A, 'Sarcomere,' is incorrect as a sarcomere is the basic unit of muscle contraction, not the point of contact between a motor neuron and a muscle fiber. Choice C, 'Tendon,' is incorrect as tendons are fibrous connective tissues that connect muscle to bone, not involved in neuronal communication. Choice D, 'Myofibril,' is incorrect as a myofibril is a structure within muscle fibers where muscle contractions occur, not the specific point of contact for communication between a motor neuron and a muscle fiber.

3. Parkinson's disease is a neurodegenerative disorder affecting which neurotransmitter?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. Glutamate

Correct answer: A

Rationale: Parkinson's disease is primarily caused by the loss of dopamine-producing neurons in the brain. Dopamine is a neurotransmitter that plays a crucial role in coordinating movement. The reduction of dopamine levels leads to the characteristic motor symptoms of Parkinson's disease, such as tremors, rigidity, and bradykinesia. Choice B, acetylcholine, is involved in functions like muscle contraction and autonomic nervous system regulation but is not primarily affected in Parkinson's disease. Serotonin (Choice C) is involved in mood regulation and sleep, not the main neurotransmitter affected in Parkinson's disease. Glutamate (Choice D) is the major excitatory neurotransmitter in the central nervous system and is not primarily implicated in Parkinson's disease pathophysiology.

4. Which of the following correctly lists the normal blood flow through the heart?

• A. Left ventricle, left atrium, body, right ventricle, right atrium, lungs
• B. Left atrium, left ventricle, lungs, right atrium, right ventricle, body
• C. Right atrium, right ventricle, lungs, left atrium, left ventricle, body
• D. Right ventricle, right atrium, body, left atrium, left ventricle, lungs

Correct answer: B

Rationale: The correct order of normal blood flow through the heart is as follows: from the body, blood flows into the right atrium, then to the right ventricle, followed by the lungs through the pulmonary artery for oxygenation. Oxygenated blood then returns to the heart through the pulmonary veins into the left atrium, then moves into the left ventricle before being pumped out to the body. Choice B correctly depicts this sequential flow of blood through the heart. Choices A, C, and D are incorrect as they do not follow the typical path of blood flow through the heart.

5. What is the unit of measurement for density?

• A. Grams per liter (g/L)
• B. Kilograms per cubic meter (kg/m³)
• C. Pounds per square inch (psi)
• D. Newtons per meter (N/m)

Correct answer: A

Rationale: Density is defined as mass per unit volume. The most commonly used unit for density in the metric system is grams per liter (g/L). Kilograms per cubic meter (kg/m³) is also a common unit for density, but grams per liter is more frequently used in everyday measurements. Pounds per square inch (psi) is a unit of pressure, not density. Newtons per meter (N/m) is a unit of force per unit length, not density.

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