Nursing Elites

1. Which layer of the skin is responsible for new skin cell production?

• A. Stratum corneum
• B. Stratum basale
• C. Stratum granulosum
• D. Stratum spinosum

Correct answer: B

Rationale: The correct answer is B, Stratum basale. The stratum basale, also known as the basal layer or stratum germinativum, is the deepest layer of the epidermis and is responsible for new skin cell production through cell division. It contains basal cells that continuously divide to produce new keratinocytes, which move up through the layers of the epidermis. Choice A, Stratum corneum, is the outermost layer of the epidermis consisting of dead cells filled with keratin. It serves a protective function but is not involved in new skin cell production. Choice C, Stratum granulosum, is a layer of the epidermis where keratinocytes undergo changes in their structure and composition. It is involved in the process of keratinization but not in new skin cell production. Choice D, Stratum spinosum, is a layer of the epidermis where cells become interconnected by desmosomes. While it plays a role in providing strength and support to the epidermis, it is not primarily responsible for new skin cell production.

2. What is the term for the process of converting a liquid into a gas at a temperature below its boiling point?

• A. Vaporization
• B. Evaporation
• C. Condensation
• D. Sublimation

Correct answer: B

Rationale: Evaporation is the correct term for the process of converting a liquid into a gas at a temperature below its boiling point. During evaporation, molecules of the liquid gain enough energy to escape into the gas phase, primarily occurring at the liquid's surface. Vaporization is a broader term that encompasses the conversion of a substance from a liquid or solid state to a gas, not specifically at temperatures below the boiling point. Condensation is the reverse process of evaporation, involving the conversion of a gas into a liquid. Sublimation, on the other hand, refers to the direct transition of a substance from the solid phase to the gas phase without passing through the liquid phase.

3. How does urine flow through the urethra?

• A. Continuously
• B. Only when the bladder is completely full
• C. Under voluntary control of sphincter muscles
• D. A combination of B and C

Correct answer: C

Rationale: Urine flows through the urethra under voluntary control of sphincter muscles. These muscles can be consciously contracted or relaxed to control the flow of urine from the bladder to the outside of the body. Choice A is incorrect as urine flow is not continuous but rather regulated. Choice B is incorrect because urine flow is not restricted to only when the bladder is completely full. Choice D is incorrect as it inaccurately combines the two incorrect statements of choices B and C.

4. How does the Law of Conservation of Mass apply to this reaction: 2H₂ + O₂ → 2H₂O?

• A. Electrons are not lost.
• B. The hydrogen does not lose mass.
• C. New water molecules are formed.
• D. There is no decrease or increase in matter.

Correct answer: D

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction. In the given reaction, 2 moles of hydrogen combine with 1 mole of oxygen to form 2 moles of water. The total mass of the reactants (hydrogen and oxygen) is equal to the total mass of the products (water), meaning there is no decrease or increase in matter. The total mass of the system remains constant, demonstrating the conservation of mass. Choices A, B, and C are incorrect because the conservation of mass does not specifically relate to electrons, individual elements (like hydrogen), or the formation of new molecules; instead, it focuses on the overall mass of the system before and after the reaction.

5. What is the difference between isometric and isotonic muscle contractions?

• A. Isometric involves movement, while isotonic does not.
• B. Isotonic involves shortening of muscle, while isometric maintains length.
• C. Isometric uses more energy, while isotonic uses less.
• D. Isotonic involves smooth muscle, while isometric involves skeletal muscle.

Correct answer: B

Rationale: The correct answer is B. Isometric contractions occur when the muscle generates tension without changing its length, while isotonic contractions involve the muscle changing length to move a load. In isotonic contractions, the muscle shortens to move a load, whereas in isometric contractions, the muscle contracts to hold a position without movement. Choice A is incorrect because isometric contractions do not involve movement, while choice C is incorrect as isotonic contractions typically require more energy due to movement. Choice D is incorrect because the type of muscle involved (smooth or skeletal) is not the defining factor between isometric and isotonic contractions.

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