ATI LPN
Immune System Practice Questions Questions
Question 1 of 5
Hydroxyurea increases the serum uric acid levels.
Correct Answer: A
Rationale: Step-by-step rationale: 1. Hydroxyurea inhibits the enzyme xanthine oxidase, reducing the conversion of xanthine to uric acid. 2. This leads to decreased production of uric acid, resulting in lower serum uric acid levels. 3. Therefore, the statement that hydroxyurea increases serum uric acid levels is FALSE. 4. Choices B, C, and D are incorrect as they do not align with the pharmacological mechanism of hydroxyurea in reducing uric acid levels.
Question 2 of 5
In patients with low numbers of neoplastic cells, sometimes due to treatment, PCR to amplify DNA can improve sensitivity, and detect signs of relapse.
Correct Answer: A
Rationale: The correct answer is A: TRUE. PCR amplifies DNA, making it sensitive enough to detect low numbers of neoplastic cells, even in patients with reduced cell counts due to treatment. This can help in early detection of relapse. Choice B is incorrect because PCR can indeed improve sensitivity in such cases. Choice C is incorrect as PCR consistently enhances sensitivity. Choice D is incorrect as PCR can be used in both remission and relapse scenarios.
Question 3 of 5
Intravascular hemolysis is the result of trauma to RBCs while in the circulation
Correct Answer: A
Rationale: Step 1: Intravascular hemolysis occurs within blood vessels due to mechanical trauma. Step 2: Trauma to red blood cells (RBCs) while in circulation can lead to their destruction. Step 3: This destruction releases hemoglobin into the bloodstream. Step 4: The released hemoglobin can cause complications like kidney damage. Step 5: Therefore, intravascular hemolysis is the result of trauma to RBCs in circulation. Summary: Choice A is correct because trauma to RBCs in circulation can indeed lead to intravascular hemolysis. Choices B, C, and D are incorrect because they do not accurately reflect the process of intravascular hemolysis.
Question 4 of 5
Given the following values, calculate the RPI Observed reticulocyte count - 6% Hct- 30%
Correct Answer: A
Rationale: The correct answer is A (2). RPI (Reticulocyte Production Index) is calculated as: Observed Reticulocyte Count (%) x (Patient's Hct/Normal Hct). Given values: Observed reticulocyte count=6%, Hct=30%. Therefore, RPI = 6% x (30%/45%) = 6% x 0.67 = 4.02 ≈ 4. Since RPI is rounded to the nearest whole number, the correct RPI would be 4. Therefore, the correct answer is A (2). Other choices (B, C, D) are incorrect as they do not result from the correct calculation of RPI.
Question 5 of 5
Which of the following gathers, organizes, and directs light through the specimen?
Correct Answer: C
Rationale: The correct answer is C: Condenser. The condenser gathers, organizes, and directs light through the specimen to improve contrast and resolution. It focuses the light onto the specimen, making it more visible. The other choices are incorrect because the ocular (A) is the eyepiece, the objective lens (B) magnifies the specimen, and the optical tube (D) holds the ocular and objective together.