Inflammation and Repair Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Inflammation and Repair. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Inflammation and Repair Indian Medical PG Question 1: The acute inflammatory response is predominantly mediated by which type of immune cells?
- A. T lymphocytes
- B. Neutrophils (Correct Answer)
- C. Both B and T lymphocytes
- D. B lymphocytes
Inflammation and Repair Explanation: ***Neutrophils***
- **Neutrophils** are the **primary mediators** of the **acute inflammatory response**, being the first immune cells recruited to sites of injury or infection (usually within minutes to hours) [1], [3].
- They are **innate immune cells** that perform phagocytosis, release antimicrobial substances, and form neutrophil extracellular traps (NETs) to combat pathogens [1].
- Neutrophils constitute **50-70% of circulating leukocytes** and are the hallmark cells found in acute inflammation [3].
*T lymphocytes*
- **T lymphocytes** are central to **cell-mediated immunity** in the adaptive immune response, requiring several days for activation and clonal expansion [2].
- They recognize specific antigens through TCRs and are not involved in the immediate, non-specific phase of acute inflammation.
- T cells play roles in **chronic inflammation** and coordinating adaptive immunity, not acute responses.
*B lymphocytes*
- **B lymphocytes** mediate **humoral immunity** by producing antibodies during the adaptive immune response [1].
- Their activation, differentiation into plasma cells, and antibody production take days to weeks, making them irrelevant to the rapid acute inflammatory response.
- B cells are not recruited to acute inflammatory sites in the initial phase.
*Both B and T lymphocytes*
- While both are critical for **adaptive immunity** and host defense, neither B nor T lymphocytes are primary mediators of acute inflammation [4].
- The acute inflammatory response relies on **innate immune cells** (neutrophils, macrophages, mast cells) for immediate, non-specific protection before adaptive immunity develops [4].
Inflammation and Repair Indian Medical PG Question 2: First mediator of inflammation to be released is
- A. Nitric oxide
- B. PAF
- C. Histamine (Correct Answer)
- D. IL-1
Inflammation and Repair Explanation: ***Histamine***
- Histamine is the **first mediator of inflammation released** by mast cells and basophils during an allergic or inflammatory response [1][3].
- It promotes **vasodilation** and increased vascular permeability, leading to typical symptoms of inflammation [1][2].
*PAF*
- Platelet-activating factor (PAF) is released later in the inflammatory process and is primarily involved in **amplifying** the response rather than initiating it.
- It plays a role in **platelet aggregation** and acting on vascular smooth muscle but is not the first released mediator.
*Nitric oxide*
- Nitric oxide is produced by endothelial cells and plays a role in **vascular relaxation and inflammation**, but it is not among the first mediators released.
- It is involved in more **regulatory functions** in the inflammatory response rather than the initial trigger.
*IL-1*
- Interleukin-1 (IL-1) is a cytokine that is important for the **inflammatory response**, but it is produced after the initial release of mediators like histamine [2].
- It is primarily secreted by **activated macrophages** and contributes to the **amplification** of the immune response [2].
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 84-85.
[2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 101.
[3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 93-94.
Inflammation and Repair Indian Medical PG Question 3: Which of the following protein molecules is responsible for cell-to-cell adhesion?
- A. Laminin
- B. Fibronectin
- C. Collagen
- D. Cadherin (Correct Answer)
Inflammation and Repair Explanation: ***Cadherin***
- **Cadherins** are transmembrane proteins that mediate **direct cell-to-cell adhesion** in a calcium-dependent manner
- They form **adherens junctions** and **desmosomes**, which are essential for maintaining tissue integrity
- Cadherins on adjacent cells bind to each other (**homophilic binding**), creating strong cell-cell connections
- Critical for **embryonic development**, tissue architecture, and **epithelial barrier function**
*Fibronectin*
- **Fibronectin** is an extracellular matrix glycoprotein that mediates **cell-to-ECM adhesion**, not direct cell-to-cell adhesion
- It binds to **integrins** on the cell surface, facilitating cell attachment to the extracellular matrix
- Important for cell migration, wound healing, and embryonic development
- Does not directly connect cells to each other
*Collagen*
- **Collagen** is the most abundant structural protein providing **tensile strength** to connective tissues
- Primarily functions as **extracellular scaffolding**, not as an adhesion molecule
- Provides mechanical support but does not mediate cell-cell adhesion
*Laminin*
- **Laminins** are major components of the **basal lamina** (basement membrane)
- Mediate **cell-to-basal lamina adhesion** through integrin receptors
- Important for cell differentiation, migration, and tissue organization
- Function in cell-to-ECM adhesion, not cell-to-cell adhesion
Inflammation and Repair Indian Medical PG Question 4: Which of the following is a secondary mediator of anaphylaxis?
- A. Leukotriene B4 (Correct Answer)
- B. Protease
- C. Histamine
- D. Eosinophilic chemotactic factor
Inflammation and Repair Explanation: ***Leukotriene B4***
- **Leukotrienes** are synthesized from **arachidonic acid** via the 5-lipoxygenase pathway during an anaphylactic reaction, making them **secondary mediators**.
- **Leukotriene B4** is a potent **chemoattractant for neutrophils** and contributes to the inflammatory response in anaphylaxis.
- Note: The **cysteinyl leukotrienes (LTC4, LTD4, LTE4)** are the primary leukotrienes responsible for **bronchoconstriction** and increased vascular permeability in anaphylaxis.
*Protease*
- **Proteases**, such as **tryptase**, are **preformed mediators** stored in mast cell granules and are rapidly released upon activation.
- They are considered **primary mediators** due to their immediate release following mast cell degranulation.
*Histamine*
- **Histamine** is a classic **preformed mediator** stored in mast cell granules and is one of the first substances released during anaphylaxis.
- Its rapid release causes immediate effects such as **vasodilation**, **bronchoconstriction**, and increased vascular permeability.
*Eosinophilic chemotactic factor*
- **Eosinophilic chemotactic factor (ECF-A)** is a **preformed mediator** stored in mast cell granules.
- While it attracts eosinophils, it is released immediately from granules upon mast cell activation, classifying it as a **primary mediator**.
Inflammation and Repair Indian Medical PG Question 5: Which of the following is/are characteristic features of chronic inflammation?
- A. Infiltration of neutrophils
- B. Tissue fibrosis and lymphocyte infiltration (Correct Answer)
- C. Increased blood flow (hyperemia)
- D. Presence of fluid accumulation (edema) in tissues
Inflammation and Repair Explanation: ***Tissue fibrosis and lymphocyte infiltration***
- **Chronic inflammation** is characterized by the persistent presence of lymphocytes, plasma cells, and macrophages as the predominant inflammatory cells [1].
- **Tissue fibrosis** (scarring) and destruction are hallmarks of chronic inflammation as the body attempts to repair ongoing damage, often leading to loss of organ function [1].
*Infiltration of neutrophils*
- **Neutrophils** are the primary inflammatory cells seen in **acute inflammation**, being the first responders to injury or infection [2].
- Their presence typically signifies an active, recent inflammatory process, usually resolving within hours to days.
*Increased blood flow (hyperemia)*
- **Hyperemia** is a classic sign of **acute inflammation**, contributing to the **redness and warmth** observed at the site.
- While some vascular changes can persist in chronic inflammation, pronounced and primary hyperemia is characteristic of the acute phase.
*Presence of fluid accumulation (edema) in tissues*
- **Edema** primarily results from increased vascular permeability, a key feature of **acute inflammation**, causing swelling [2].
- While some edema may be present in chronic inflammation due to persistent vascular leakage, it is a dominant feature of acute inflammatory responses.
**References:**
[1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 109-110.
[2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 103-104.
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