Inflammation and Repair Practice Questions

Q: Which among the following is a vasoconstrictor?

Thromboxane A2 (TXA2). **Explanation:** The correct answer is **Thromboxane A2 (TXA2)**. In the context of inflammation and hemostasis, vasoactive mediators are classified based on their effect on vascular smooth muscle. **Thromboxane A2 (TXA2)** is a potent **vasoconstrictor** and a powerful inducer of platelet aggregation [1]. It is synthesized from arachidonic acid via the cyclooxygenase (COX) pathway, primarily within platelets [1]. Its primary physiological role is to limit blood flow at the site of injury and facilitate the formation of a platelet plug. **Analysis of Incorrect Options:** * **Histamine:** One of the first mediators released during acute inflammation (from mast cell degranulation). It causes **vasodilation** of arterioles and increases the permeability of venules [1]. * **Prostacyclin (PGI2):** Produced by vascular endothelium, it acts as the functional antagonist to TXA2. It is a potent **vasodilator** and an inhibitor of platelet aggregation, maintaining vascular patency. * **Bradykinin:** A peptide of the kinin system that causes significant **vasodilation**, increased vascular permeability, and mediates pain. **High-Yield Clinical Pearls for NEET-PG:** * **Vasoconstrictors to remember:** Thromboxane A2, Leukotrienes (C4, D4, E4), Endothelin, and Angiotensin II [1]. * **Vasodilators to remember:** Histamine, Prostaglandins (PGE2, PGD2, PGF2α, PGI2), Nitric Oxide (NO), and Bradykinin [1]. * **Aspirin Connection:** Low-dose aspirin irreversibly inhibits COX-1 in platelets, reducing TXA2 levels, which explains its clinical use as an anti-platelet/cardioprotective agent. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 94-95.

Q: Which cytokine possesses pyrogenic activity?

IL-6. **Explanation:** **Correct Option: A (IL-6)** Fever (pyrexia) is mediated by **pyrogens**. Cytokines such as **IL-1, TNF-̑, and IL-6** act as endogenous pyrogens [1]. When released (primarily by macrophages), these cytokines travel via the bloodstream to the anterior hypothalamus. Here, they induce the enzyme **cyclooxygenase (COX)**, which converts arachidonic acid into **Prostaglandin E2 (PGE2)** [1]. PGE2 resets the hypothalamic thermostat to a higher level, resulting in fever. Among the options provided, IL-6 is a potent inducer of the acute-phase response and pyrogenesis [1]. **Incorrect Options:** * **B. IL-8:** This is a potent **chemotactic factor** for neutrophils. Its primary role is "recruitment" rather than systemic thermoregulation. * **C. TGF-beta:** This is an **anti-inflammatory** and profibrotic cytokine. It helps in wound healing and limits the immune response; it does not induce fever. * **D. IL-3:** This is a hematopoietic growth factor (multilineage colony-stimulating factor) that stimulates the differentiation of stem cells in the bone marrow [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Major Endogenous Pyrogens:** IL-1 (most potent), TNF, and IL-6. * **Acute Phase Reactants:** IL-6 is the primary stimulator for the hepatic synthesis of acute-phase proteins like **CRP** and Fibrinogen [1]. * **Mechanism of NSAIDs:** Drugs like Paracetamol and Aspirin reduce fever by inhibiting COX, thereby blocking the synthesis of PGE2 in the hypothalamus. * **IL-8 Mnemonic:** "Clean up on aisle 8"—IL-8 recruits neutrophils to clean up the site of inflammation. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 111.

Question 1

All of the following are true regarding vasodilation in acute inflammation, except?

Accepted Answer

First affects arterioles and followed by opening of capillaries

Answer

Caused by release of histamine

Answer

Vasodilation leads to extravasation of fluid from microvasculature, leading to edema

Answer

Vasodilation occurs notably due to the action of histamine on vascular smooth muscle

Question 2

Which of the following is NOT involved in phagocytosis?

Accepted Answer

Pavementing of cells

Answer

Recognition and attachment

Answer

Engulfment

Answer

Killing and degradation

Question 3

What is the earliest feature of reversible cell injury?

Accepted Answer

Hydropic swelling

Answer

Amorphous densities

Answer

Ribosomal detachment

Answer

Bleb formation

Question 4

Which among the following is a vasoconstrictor?

Accepted Answer

Thromboxane A2 (TXA2)

Answer

Histamine

Answer

Prostacyclin (PGI2)

Answer

Bradykinin

Question 5

Which cytokine possesses pyrogenic activity?

Accepted Answer

IL-6

Answer

IL-8

Answer

TGF beta

Answer

IL-3

Question 6

All are factors of poor wound healing EXCEPT?

Accepted Answer

Young age

Answer

Infection

Answer

Zinc deficiency

Answer

Vitamin D deficiency

Question 7

Which vasoactive amine is involved in inflammation?

Accepted Answer

Histamine

Answer

Dopamine

Answer

Adrenaline

Answer

Angiotensin

Question 8

What is the most characteristic feature of acute inflammation?

Accepted Answer

Vasodilation and increased vascular permeability

Answer

Vasoconstriction

Answer

Vascular stasis

Answer

Margination of leucocytes

Question 9

A scientist is working in the laboratory on the mechanisms involved in inflammation. He observes that leucocytes leave the blood vessels and move towards the site of bacteria. Which of the following is likely to mediate this movement of leucocytes?

Accepted Answer

C5a

Answer

C3a

Answer

Histamine

Answer

C3b

Question 10

Which of the following exhibits both morphogenic and mitogenic properties?

Accepted Answer

Bone morphogenetic protein

Answer

Fibroblast growth factor

Answer

Platelet derived growth factor

Answer

Insulin-like growth factor

Inflammation and Repair — MCQs

Inflammation and Repair — MCQs

On this page

Practice by Chapter

Want unlimited practice?