Inflammation and Repair Practice Questions

Q: Which of the following is NOT associated with integrins?

Rolling. To master the process of **Leukocyte Extravasation**, it is essential to distinguish between the specific adhesion molecules involved at each step. [1] ### **Why "Rolling" is the Correct Answer** **Rolling** is the initial, transient tethering of leukocytes to the endothelium. [1] This step is mediated by **Selectins** (L-selectin on leukocytes; E and P-selectin on endothelium), not integrins. [1] Selectins have low-affinity interactions that allow the cell to "roll" along the vessel wall under the force of blood flow. [1] ### **Analysis of Other Options** * **Adhesion (B) & Arrest (C):** These steps occur when rolling leukocytes are activated by chemokines, causing a conformational change in **Integrins** (e.g., LFA-1, VLA-4) from a low-affinity to a **high-affinity state**. [1] These integrins bind firmly to ligands like **ICAM-1** and **VCAM-1** on the endothelium, leading to the "arrest" or firm attachment of the cell. [1] * **Transmigration (D):** Also known as diapedesis, this involves leukocytes squeezing through endothelial junctions. While **PECAM-1 (CD31)** is the primary mediator here, certain integrins also facilitate the crawling and squeezing process required to exit the vessel. [1] ### **High-Yield NEET-PG Pearls** * **LAD Type 1:** Caused by a deficiency in **β2-integrins (CD18)**. Clinical hallmark: Delayed separation of the umbilical cord and lack of pus formation. [1] * **LAD Type 2:** Caused by a defect in **Sialyl-Lewis X** (the ligand for Selectins), leading to a defect in **Rolling**. * **Mnemonic:** **S**electins = **S**lowing down (Rolling); **I**ntegrins = **I**mmobilization (Firm Adhesion). * **ICAM-1/VCAM-1** belong to the Immunoglobulin superfamily and act as the "docking stations" for integrins. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 87-89.

Question 1

A 28-year-old woman cuts her hand while dicing vegetables in the kitchen. The wound is cleaned and sutured. Five days later, the site of injury contains an abundance of chronic inflammatory cells that actively secrete interleukin-1, tumor necrosis factor-a, interferon- a, numerous arachidonic acid derivatives, and various enzymes. What are these cells?

Accepted Answer

Macrophages

Answer

B lymphocytes

Answer

Plasma cells

Answer

Smooth muscle cells

Question 2

In an experiment, bacteria are inoculated into aliquots of normal human blood treated with an anticoagulant. It is observed that the bacteria are either phagocytized by neutrophils or undergo lysis. Which of the following blood plasma components is most likely to facilitate these effects?

Accepted Answer

Complement

Answer

Fibrin

Answer

Kallikrein

Answer

Plasmin

Question 3

Which of the following is a chemokine?

Accepted Answer

IL-8

Answer

Leukotriene A4

Answer

C5

Answer

C3

Question 4

Abscess formation is particularly characteristic of infections with which of the following microorganisms?

Accepted Answer

Staphylococci

Answer

Viruses

Answer

Rickettsiae

Answer

Streptococci

Question 5

Chemotaxis is mediated by?

Accepted Answer

C5a

Answer

IL-2

Answer

IFN-g

Answer

IL-5

Question 6

Which of the following is NOT an action of bradykinin?

Accepted Answer

Bronchodilation

Answer

Vasodilation

Answer

Increased vascular permeability

Answer

Pain

Question 7

Which of the following is NOT associated with integrins?

Accepted Answer

Rolling

Answer

Adhesion

Answer

Arrest

Answer

Transmigration of cells

Question 8

Which of the following is the most effective bactericidal mechanism?

Accepted Answer

NADPH oxidase

Answer

Free radicals

Answer

Myeloperoxidase-halide system

Answer

Acid hydrolases

Question 9

Which of the following is NOT a cardinal sign of inflammation?

Accepted Answer

Cyanosis

Answer

Pain

Answer

Swelling

Answer

Redness

Question 10

Which of the following statements about macrophages is false?

Accepted Answer

Macrophages are involved in type III hypersensitivity reactions.

Answer

Macrophages can harbor mycobacteria.

Answer

Macrophages are derived from blood monocytes.

Answer

Macrophages produce tumor necrosis factor and interleukins.

Inflammation and Repair — MCQs

Inflammation and Repair — MCQs

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