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. An investigator wishes to test the effect of temperature on the durability of a certain material. He places five blocks of this material in a sunny area in a meadow and five more in a cold area high in the mountains. He then monitors them over time. What is the main problem with this experiment?

• A. Ten subjects are far too small a number to obtain effective results.
• B. It is impossible to control for the fact that the blocks in the mountains were placed later.
• C. There are too many variables that are not being controlled for.
• D. Nothing is wrong with this experiment; this demonstrates good experimental procedure.

Correct answer: C

Rationale: The main problem with this experiment is that there are too many variables that are not being controlled for. The investigator is only changing one variable (temperature) while there are other variables at play such as humidity, exposure to light, and potential differences in the material itself. Without controlling or accounting for these additional variables, it would be difficult to determine if any observed differences in durability are solely due to temperature. Choice A is incorrect because the issue is not solely about the number of subjects but about the lack of control over variables. Choice B is not the main problem as the order of placement may not significantly impact the results. Choice D is incorrect as the experiment lacks proper control over variables, which is a crucial aspect of good experimental procedure.

3. At what stage is urine formed in the kidney?

• A. After fluid reaches the bladder.
• B. When fluid fills the collecting duct.
• C. Before blood enters the glomerulus.
• D. During fluid transport to the urethra.

Correct answer: B

Rationale: Urine is formed when fluid fills the collecting duct in the kidney. The collecting duct is where the final concentration of urine occurs after the filtration process in the nephron. Choice A is incorrect because urine formation happens before fluid reaches the bladder. Choice C is incorrect because urine formation occurs after blood has been filtered in the glomerulus. Choice D is incorrect because urine formation happens before fluid is transported to the urethra for elimination.

4. Which component of the nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles?

• A. Autonomic nervous system
• B. Peripheral nervous system
• C. Somatic nervous system
• D. Sympathetic nervous system

Correct answer: C

Rationale: The correct answer is C: Somatic nervous system. The somatic nervous system is responsible for controlling voluntary movements, such as the contraction of skeletal muscles. This system consists of motor neurons that send signals from the central nervous system to the skeletal muscles, allowing for conscious control over movement. The autonomic nervous system (A) controls involuntary functions like heart rate and digestion, the peripheral nervous system (B) includes all nerves outside the central nervous system, and the sympathetic nervous system (D) is a division of the autonomic nervous system responsible for the fight-or-flight response. Therefore, choices A, B, and D are incorrect as they do not specifically regulate voluntary movements of skeletal muscles, which is a function of the somatic nervous system.

5. What is the function of the pons?

• A. Center for emotion and motivation
• B. Control production of hormones
• C. Relay messages from the cortex to the cerebellum
• D. Responsible for involuntary actions like breathing

Correct answer: C

Rationale: The correct function of the pons is to relay messages from the cortex to the cerebellum. The pons acts as a bridge between different brain regions, facilitating communication and coordination of movements. Choices A, B, and D are incorrect. The pons is not the center for emotion and motivation, does not control hormone production, and is not primarily responsible for involuntary actions like breathing. Understanding the role of the pons in relaying messages between brain regions is crucial for comprehending its function in the central nervous system.

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