Nursing Elites

1. How does sunscreen protect the skin from harmful ultraviolet (UV) rays?

• A. By reflecting UV rays away from the skin
• B. By absorbing UV rays and converting them to heat
• C. By blocking UV rays completely
• D. By stimulating melanin production

Correct answer: B

Rationale: Sunscreen works by absorbing UV rays and converting them to heat. This mechanism helps to prevent the UV rays from penetrating the skin and causing damage such as sunburn, premature aging, and skin cancer. Reflecting UV rays away from the skin (option A) is not the primary function of sunscreen. While sunscreen does block UV rays, it does not do so completely (option C) as some UV rays may still penetrate the skin. Sunscreen does not stimulate melanin production (option D) as a means of protecting the skin from UV rays.

2. Epithelial tissue, which covers surfaces, is further classified based on the number of cell layers. Simple epithelium has:

• A. No layers
• B. One layer
• C. Two to several layers
• D. Many tightly packed layers

Correct answer: B

Rationale: Simple epithelium consists of a single layer of cells. This type of epithelium is found in areas where absorption, secretion, and filtration occur, as it allows for efficient exchange of substances across the epithelial barrier. Simple epithelium is well-suited for diffusion and filtration processes due to its thin nature, enabling substances to pass through easily. Choice A, 'No layers,' is incorrect as epithelial tissue always consists of at least one cell layer. Choice C, 'Two to several layers,' describes stratified epithelium, not simple epithelium, which has only one layer. Choice D, 'Many tightly packed layers,' is more characteristic of stratified epithelium, where multiple layers of cells are present. Therefore, the correct answer is B: 'One layer.'

3. How do efferent fibers exit the spinal cord?

• A. Through the anterior aspect
• B. Through the dorsal aspect
• C. Through the ventral aspect
• D. Through the lateral aspect

Correct answer: C

Rationale: Efferent fibers, which carry motor commands, exit the spinal cord through the ventral aspect, also known as the anterior aspect. The correct answer is C, 'Through the ventral aspect.' Efferent fibers exiting through the ventral aspect are responsible for carrying motor commands from the spinal cord to the muscles and glands. Choices A, B, and D are incorrect. Efferent fibers do not exit through the dorsal, lateral, or anterior aspects of the spinal cord.

4. What factors can contribute to edema, a condition characterized by swelling due to a buildup of lymph fluid?

• A. Regular exercise
• B. Maintaining a healthy weight
• C. Poor circulation or blockage in the lymphatic system
• D. Proper hydration

Correct answer: C

Rationale: Edema is caused by the accumulation of excess fluid in the body's tissues, leading to swelling. Poor circulation or blockage in the lymphatic system can contribute to the development of edema by impairing the body's ability to properly drain fluid. While regular exercise, maintaining a healthy weight, and proper hydration are crucial for overall health, they are not direct causes of edema. Poor circulation or blockage in the lymphatic system disrupts the normal balance of fluid in the body, resulting in edema. Therefore, the correct factor that can contribute to edema is poor circulation or blockage in the lymphatic system.

5. The Minimum Inhibitory Concentration (MIC) of an antibiotic refers to:

• A. The lowest concentration that kills bacteria
• B. The dose required for 50% bacterial inhibition
• C. The time it takes for an antibiotic to work
• D. The spectrum of bacteria the antibiotic targets

Correct answer: B

Rationale: A) The lowest concentration that kills bacteria is known as the Minimum Bactericidal Concentration (MBC), not the Minimum Inhibitory Concentration (MIC). MIC is the lowest concentration of an antibiotic that inhibits visible growth of bacteria. B) The MIC of an antibiotic is the concentration at which bacterial growth is inhibited by 50%. This concentration is used to determine the effectiveness of an antibiotic against a specific bacterium. C) The time it takes for an antibiotic to work is not described by the MIC. MIC is a measure of concentration, not time. D) The spectrum of bacteria the antibiotic targets is not defined by the MIC. The MIC value is specific to a particular antibiotic and bacterium, regardless of the spectrum of activity of the antibiotic.

Similar Questions