Nursing Elites

1. The fatty sheath that insulates some nerve fibers and speeds up signal transmission is called the:

• A. Myelin sheath
• B. Dura mater
• C. Pia mater
• D. Arachnoid mater

Correct answer: A

Rationale: The correct answer is A: Myelin sheath. The myelin sheath is a fatty layer that surrounds and insulates certain nerve fibers. It acts as an electrical insulator, speeding up the transmission of nerve impulses along the axon. This insulation helps to prevent signal loss or interference, allowing for faster and more efficient communication between neurons. The other options, B: Dura mater, C: Pia mater, and D: Arachnoid mater, are all layers of the meninges that protect the brain and spinal cord, but they do not play a role in insulating nerve fibers for signal transmission like the myelin sheath does.

2. An IV bag contains 500ml of saline solution and needs to be infused over 4 hours. What is the flow rate in drops per minute, assuming 20 drops per milliliter?

• A. 12.5 drops/min
• B. 25 drops/min
• C. 50 drops/min
• D. 100 drops/min

Correct answer: C

Rationale: Calculate the total volume in drops (500ml * 20 drops/ml = 10,000 drops). Divide this by the infusion time in minutes (4 hours * 60 minutes/hour = 240 minutes) to get the flow rate.

3. Which of the following is NOT a function of the endocrine system?

• A. Regulating growth and development
• B. Maintaining blood sugar levels
• C. Controlling mood and emotions
• D. Facilitating digestion through muscle contractions

Correct answer: D

Rationale: The endocrine system is responsible for producing hormones that regulate various bodily functions. Option D, facilitating digestion through muscle contractions, is actually a function of the muscular and digestive systems, not the endocrine system. The endocrine system primarily regulates growth and development, maintains blood sugar levels through hormones like insulin and glucagon, and also plays a role in controlling mood and emotions through hormones such as serotonin and cortisol. Therefore, option D is correct as it is not a function directly associated with the endocrine system.

4. What protein complex controls the progression of mitosis through its activation and degradation?

• A. Ribosome
• B. Cyclin-dependent kinase (CDK)
• C. Centriole
• D. Microtubule

Correct answer: B

Rationale: Rationale: A) Ribosome: Ribosomes are cellular organelles responsible for protein synthesis and are not directly involved in controlling the progression of mitosis. B) Cyclin-dependent kinase (CDK): CDKs are a family of protein kinases that regulate the cell cycle, including the progression of mitosis. CDK activity is controlled by cyclins, which bind to CDKs to activate them at specific points in the cell cycle. The activation and degradation of cyclins regulate the activity of CDKs, which in turn control the progression of mitosis. C) Centriole: Centrioles are involved in organizing the microtubules of the mitotic spindle but do not directly control the progression of mitosis. D) Microtubule: Microtubules are structural components of the cytoskeleton and are involved in various cellular processes, including mitosis, but they do not control

5. The body's first line of defense against pathogens includes:

• A. Phagocytes
• B. Antibodies
• C. Memory B cells
• D. T lymphocytes

Correct answer: A

Rationale: Rationale: Phagocytes are a type of white blood cell that plays a crucial role in the body's innate immune response, which is the first line of defense against pathogens. Phagocytes engulf and digest foreign particles, such as bacteria and viruses, helping to prevent infection and disease. Antibodies (option B) are produced by B cells and are part of the adaptive immune response, not the first line of defense. Memory B cells (option C) are also part of the adaptive immune response and are involved in mounting a faster and stronger response upon re-exposure to a pathogen. T lymphocytes (option D) are another type of white blood cell involved in the adaptive immune response, specifically in cell-mediated immunity.

6. The order of operations (PEMDAS) dictates the sequence for evaluating mathematical expressions. If a = 2 and b = -3, what is the value of 3a^2 - 2ab + b^2?

• A. -3
• B. 0
• C. 33
• D. 15

Correct answer: C

Rationale: Following PEMDAS (Parentheses, Exponents, Multiplication and Division from left to right, Addition and Subtraction from left to right), we start with exponents: 3(2^2) - 2ab + b^2. Then, multiply: 3(4) - 2ab + b^2. Next, perform the multiplication/division from left to right: 12 - 2ab + b^2. Finally, add/subtract from left to right: 12 + (-2)(2)(-3) + (-3)^2. Evaluate the remaining terms: 12 + 12 + 9. The answer is 33.

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