Inflammation and Repair Practice Questions

Q: What is the most potent chemoattractant for neutrophils?

IL-8. **Explanation:** The recruitment of leukocytes to a site of inflammation is a highly regulated process involving cytokines and chemokines. **Interleukin-8 (IL-8)**, also known as CXCL8, is a specialized chemokine produced by macrophages, endothelial cells, and epithelial cells. Its primary function is the **potent chemoattraction and activation of neutrophils**. It binds to CXCR1 and CXCR2 receptors on neutrophils, inducing a conformational change in integrins (increasing adhesion) and directing their migration through the vascular wall toward the site of injury (chemotaxis). **Analysis of Incorrect Options:** * **IL-1:** This is a pro-inflammatory cytokine primarily involved in inducing **fever** (endogenous pyrogen) and upregulating adhesion molecules (E-selectin) on endothelial cells. While it initiates the inflammatory cascade, it is not a direct chemoattractant for neutrophils. * **IL-6:** This cytokine is the chief stimulator of the **acute-phase response** in the liver (inducing CRP, fibrinogen, and hepcidin). It bridges innate and adaptive immunity but does not function as a primary neutrophil chemoattractant. * **IL-2:** Produced by T-cells (Th1), IL-2 is a T-cell growth factor responsible for the **proliferation and differentiation of T-lymphocytes** and NK cells. It has no direct role in neutrophil recruitment. **High-Yield Clinical Pearls for NEET-PG:** * **Other potent neutrophil chemoattractants:** Apart from IL-8, remember **LTB4** (Leukotriene B4), **C5a** (Complement component), and **fMet-Leu-Phe** (bacterial products). * **Mnemonic for Neutrophil Chemotaxis:** "Clean Up On Aisle 8" (C5a, LTB4, Other bacterial products, IL-8). * IL-8 also plays a role in **angiogenesis**, which is relevant in tumor metastasis.

Q: A patient presents with a wound on his leg. It heals six weeks later. Which of the following mediators is involved in promoting wound healing?

TGF-Beta. **Explanation:** **TGF-Beta (Transforming Growth Factor-Beta)** is the correct answer because it is the most critical cytokine involved in the **proliferative and remodeling phases** of wound healing. It acts as a potent fibrogenic agent by: 1. Stimulating the chemotaxis and proliferation of fibroblasts. 2. Increasing the synthesis of collagen and fibronectin while decreasing the degradation of the extracellular matrix (ECM) by inhibiting metalloproteinases. 3. Promoting angiogenesis and epithelialization. **Analysis of Incorrect Options:** * **TNF-Alpha (Tumor Necrosis Factor-Alpha):** This is a potent pro-inflammatory cytokine produced by macrophages. While it is involved in the initial inflammatory phase of wound healing, its chronic elevation actually impairs healing and is associated with chronic non-healing ulcers. * **IFN-Alpha & IFN-Beta (Type I Interferons):** These are primarily involved in innate antiviral immunity and the activation of MHC class I expression. They do not play a direct role in promoting collagen synthesis or tissue repair; in fact, interferons can sometimes inhibit fibroblast proliferation. **NEET-PG High-Yield Pearls:** * **TGF-Beta** is also known for its role in **limiting inflammation** (anti-inflammatory) and is a key mediator in the development of fibrosis in chronic organs (e.g., liver cirrhosis, pulmonary fibrosis). * **Platelet-Derived Growth Factor (PDGF)** is another high-yield mediator that works alongside TGF-Beta to trigger fibroblast migration and smooth muscle proliferation. * **Vitamin C and Zinc** are essential cofactors for collagen synthesis during the remodeling phase; deficiency leads to poor wound healing.

Question 1

What is the primary role of P-selectin in the process of inflammation?

Accepted Answer

Rolling of leukocytes along the endothelium

Answer

Stable adhesion of leukocytes to the endothelium

Answer

Directing leukocytes to specific lymphoid tissues

Answer

Passage of leukocytes through the endothelial barrier

Question 2

What is the most potent chemoattractant for neutrophils?

Accepted Answer

IL-8

Answer

IL-1

Answer

IL-6

Answer

IL-2

Question 3

A keloid scar is primarily composed of which type of tissue?

Accepted Answer

Dense collagen

Answer

Loose fibrous tissue

Answer

Granulomatous tissue

Answer

Loose areolar tissue

Question 4

Following surgery, the wound heals in a linear fashion without any complication. This type of healing is called?

Accepted Answer

Primary healing

Answer

Secondary healing

Answer

Delayed primary healing

Answer

Reepithelialization

Question 5

A 10-year-old male child complains of pain and swelling in the left foot after an injury while playing. What mediates the migration of leukocytes to the site of injury?

Accepted Answer

Chemokines

Answer

Cytokines

Answer

Histamine

Answer

Prostaglandins

Question 6

A patient presents with a wound on his leg. It heals six weeks later. Which of the following mediators is involved in promoting wound healing?

Accepted Answer

TGF-Beta

Answer

TNF-Alpha

Answer

INF-Beta

Answer

IFN-Alpha

Question 7

Which of the following hormones has the greatest effect on granulation tissue in wound healing?

Accepted Answer

Cortisol

Answer

Antidiuretic hormone (ADH)

Answer

Estrogen

Answer

Parathormone

Question 8

Which of the following is a preformed mediator of inflammation?

Accepted Answer

Serotonin

Answer

Prostaglandin

Answer

Dopamine

Answer

Leukotrienes

Question 9

A 54-year-old man presents with poor wound healing following laparoscopic hernia repair, despite small incision size. Further history reveals a diet deficient in vitamin C. Which extracellular matrix component's synthesis is most significantly affected by vitamin C deficiency?

Accepted Answer

Collagen

Answer

Elastin

Answer

Fibronectin

Answer

Integrin

Question 10

Which of the following is a sign of chronic inflammation?

Accepted Answer

Angiogenesis

Answer

Purulent exudate

Answer

Induration

Answer

Edema

Inflammation and Repair — MCQs

Inflammation and Repair — MCQs

On this page

Practice by Chapter

Want unlimited practice?