Tissue Repair and Wound Healing — MCQs
Intermediate filaments in connective tissue are which type of structural component?
First cell to migrate into a wound due to chemotaxis to start the process of wound healing is -
Regeneration is characterized by:
Which of the following is most radioresistant?
Maximum collagen deposition in wound healing is seen at -
Most radiosensitive stage of the cell cycle –
Which of the following statements about wound healing is false?
Which of the following is not considered an example of excess tissue growth?
Which of the following type of collagen is present in healing and granulation tissue?
Which of the following substances is a growth factor that is capable of inducing all the steps necessary for angiogenesis?
Tissue Repair and Wound Healing Indian Medical PG Practice Questions and MCQs
Question 1: Intermediate filaments in connective tissue are which type of structural component?
- A. Keratin
- B. Vimentin (Correct Answer)
- C. Lamin
- D. Desmin
Explanation: ***Vimentin*** - **Vimentin** is the most common intermediate filament found in cells of **mesenchymal origin**, including those in connective tissue (e.g., fibroblasts) [1]. - It plays a crucial role in maintaining **cell shape**, integrity, and in processes like cell migration and adhesion within connective tissue [1]. *Keratin* - **Keratins** (also known as cytokeratins) are the primary intermediate filaments found in **epithelial cells**, providing structural integrity to tissues like skin, hair, and nails [1]. - They are not typically found in connective tissue cells, which have different structural requirements. *Desmin* - **Desmin** is an intermediate filament predominantly found in **muscle cells** (skeletal, cardiac, and smooth muscle). - It helps in maintaining the structural and mechanical integrity of the **sarcomere** and muscle fibers. *Lamin* - **Lamins** are unique intermediate filaments that form the **nuclear lamina**, a fibrous network underlying the inner nuclear membrane found in almost all nucleated cells. - They provide structural support to the nucleus and are involved in chromatin organization and gene regulation.
Question 2: First cell to migrate into a wound due to chemotaxis to start the process of wound healing is -
- A. Lymphocyte
- B. Macrophage
- C. Platelet
- D. Neutrophil (Correct Answer)
Explanation: ***Neutrophil*** - Neutrophils are the **first responders** in the wound healing process, rapidly migrating to the site due to **chemotactic signals** [1,2]. - Their primary role includes **phagocytosing pathogens** and debris, facilitating the subsequent healing phases. *Lymphocyte* - Lymphocytes typically arrive later in the healing process and are mainly involved in **immune response** rather than initial wound healing. - They play a significant role in **adaptive immunity** but do not participate in the **early inflammatory phase**. *Platelet* - While platelets aggregate at the wound site and are crucial for **clot formation**, they do not migrate into the wound through chemotaxis like neutrophils [1]. - Their primary function is to initiate the **hemostatic response** rather than directly phagocytosing debris. *Macrophage* - Macrophages are important for **later stages** of wound healing, clearing debris and coordinating tissue repair, but they arrive after neutrophils. - They are involved in the **remodeling phase** and are not the first cells to respond to the wound. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 188-189. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Migration in the tissues toward a chemotactic stimulus, pp. 86-87. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 87-89.
Question 3: Regeneration is characterized by:
- A. Granulation tissue
- B. Repairing by different type of tissue
- C. Cellular proliferation is largely regulated by biochemical factors
- D. Repairing by same type of tissue (Correct Answer)
Explanation: ***Repairing by same type of tissue*** - **Regeneration** involves the replacement of damaged cells and tissues with cells of the **same type**, leading to a complete restoration of normal structure and function [1]. - This process is seen in tissues with high proliferative capacity, like the **epidermis** or the **liver**, following injury [2]. *Granulation tissue* - **Granulation tissue** is characteristic of **repair by fibrosis** (scar formation), not regeneration [1]. - It consists of proliferating fibroblasts, new blood vessels (angiogenesis), and inflammatory cells, which eventually mature into a fibrous scar. *Repairing by different type of tissue* - The replacement of damaged tissue with a **different type of tissue** (typically fibrous connective tissue) is known as **repair by fibrosis** or **scar formation** [1]. - This occurs when the tissue's regenerative capacity is limited or when the injury is severe, resulting in the loss of normal tissue architecture and function [3]. *Cellular proliferation is largely regulated by biochemical factors* - While **cellular proliferation** is indeed regulated by **biochemical factors** (growth factors, cytokines) in both regeneration and repair, this statement describes a mechanism common to cellular growth and healing in general, not a defining characteristic unique to regeneration [1]. - This regulation guides both the replacement with original tissue (regeneration) and scar formation, so it's not specific enough to define regeneration alone. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 113-115. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 112-113. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 113.
Question 4: Which of the following is most radioresistant?
- A. Cartilage (Correct Answer)
- B. Ewing's sarcoma
- C. GIT epithelium
- D. Gonadal tumours
Explanation: ***Cartilage*** - **Cartilage** is a connective tissue with a relatively **low metabolic rate** and **avascular nature**, making its cells (chondrocytes) less susceptible to rapid turnover and DNA damage from radiation. - Its **dense extracellular matrix** and limited cellular division contribute to its inherent resistance to ionizing radiation, requiring higher doses to induce significant damage. *Ewing's sarcoma* - **Ewing's sarcoma** is a highly **malignant bone tumor** that is generally considered **radiosensitive** and often treated with radiation therapy. - Its cells are rapidly dividing, making them more vulnerable to the DNA-damaging effects of radiation. *GIT epithelium* - The **gastrointestinal tract (GIT) epithelium** is characterized by **rapid cell turnover** and high mitotic activity to constantly replace damaged cells and absorb nutrients. - This high proliferative rate makes the GIT epithelium highly **radiosensitive**, leading to common side effects like mucositis and diarrhea during radiation therapy. *Gonadal tumours* - Tumors of the **gonads** (e.g., testicular seminoma, ovarian dysgerminoma) are often highly **radiosensitive** and respond well to radiation therapy due to the germ cell origin and rapid proliferation of tumor cells. - The germ cells themselves are very sensitive to radiation, leading to concerns about **fertility preservation** in patients undergoing treatment.
Question 5: Maximum collagen deposition in wound healing is seen at -
- A. End of third week (Correct Answer)
- B. End of first week
- C. End of 2 months
- D. End of second week
Explanation: ***End of third week*** - By the end of the **third week**, the proliferative phase of wound healing is well underway, characterized by significant **collagen deposition**. [1] - At this stage, **Type III collagen** is initially laid down, which is later replaced by stronger **Type I collagen**, contributing to increasing wound strength. *End of first week* - The first week primarily involves the **inflammatory phase** and the initial stages of **proliferation**, with minimal new collagen deposition. [2] - While some **fibroblasts** are present, the amount of collagen synthesized is still relatively low. *End of second week* - Collagen synthesis is ongoing during the second week, but the **peak deposition rate** and overall amount of collagen accumulated are typically not as high as at the end of the third week. - The wound is gaining strength, but further increase in collagen content and remodeling is yet to occur. *End of 2 months* - By 2 months, the wound is in the **remodeling phase**, where the total collagen content might be substantial but the *rate of new collagen synthesis* has slowed down. - At this stage, there is a balance between **collagen synthesis** and **degradation**, and the collagen fibers are being reorganized and cross-linked to further improve tensile strength. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 117-119. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 115.
Question 6: Most radiosensitive stage of the cell cycle –
- A. M phase (Correct Answer)
- B. G2 phase
- C. S phase
- D. G1 phase
Explanation: ***M phase*** - Cells are most **radiosensitive** during the **M (mitosis) phase** due to the condensed chromosome structure and active cell division, making them highly susceptible to DNA damage. - During mitosis, the cellular machinery is focused on dividing the genetic material, making it a critical window where radiation-induced damage can easily lead to cell death. *G2 phase* - The **G2 phase** is generally considered the **second most radiosensitive phase**, although less so than M phase. - Cells in G2 are preparing for mitosis and have already replicated their DNA, but active repair mechanisms are still present, making them less vulnerable than cells undergoing active division. *S phase* - The **S (synthesis) phase**, during which DNA replication occurs, is typically the **most radioresistant phase** of the cell cycle. - Cells are actively synthesizing new DNA strands, allowing for efficient repair of DNA damage and making them less susceptible to radiation-induced lethality. *G1 phase* - The **G1 phase** is a relatively **radiosensitive phase**, but it is generally less sensitive than M phase. - Cells in G1 are growing and performing normal metabolic functions, but they have not yet replicated their DNA, allowing time for repair before DNA synthesis.
Question 7: Which of the following statements about wound healing is false?
- A. Inhibited by diabetes mellitus (DM)
- B. Inhibited by foreign body
- C. Hematomas promote wound healing (Correct Answer)
- D. Inhibited by infection
Explanation: ***Hematomas promotes wound healing*** - Hematomas (localized collections of **blood outside blood vessels**) actually **inhibit wound healing** by acting as a medium for bacterial growth and increasing tissue tension. - This statement is **false** because hematomas interfere with proper tissue apposition and oxygen delivery, which are crucial for successful wound repair [3]. *Inhibited by diabetes mellitus (DM)* - **Diabetes mellitus** impairs various stages of wound healing due to **poor glycemic control**, leading to compromised immune function, neuropathy, and reduced blood flow [1]. - This often results in **delayed wound closure** and increased risk of infection [2]. *Inhibited by foreign body* - The presence of a **foreign body** in a wound can lead to a persistent inflammatory response, impeding tissue repair and increasing the likelihood of chronic infection. - This sustained inflammation prevents the orderly progression through the phases of wound healing, thus **inhibiting the process**. *Inhibited by infection* - **Infection** in a wound significantly delays healing by causing ongoing inflammation, tissue destruction, and increased metabolic demands [1]. - Bacteria compete for nutrients and produce toxins that harm host cells, preventing proper **granulation tissue formation** and **epithelialization**. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 116-117. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 110-111. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 106-107.
Question 8: Which of the following is not considered an example of excess tissue growth?
- A. Granulation tissue (Correct Answer)
- B. Neoplasia
- C. Hyperplasia
- D. Fibrosis
Explanation: ***Granulation tissue*** - Granulation tissue is a normal part of the healing process and does not represent an **excessive growth** of tissue [3]. - It consists mainly of **new connective tissue** and blood vessels formed during healing, rather than a pathological proliferation [3]. *Hyperplasia* - Hyperplasia is characterized by an **increase in the number** of cells in a tissue, leading to tissue enlargement [1][2]. - This process is often a response to a stimulus, such as hormonal changes or injury, indicating **excess tissue growth** [2]. *Neoplasia* - Neoplasia refers to the **abnormal proliferation** of cells, forming a neoplasm or tumor, which can be benign or malignant. - This is a clear example of **excess tissue growth**, as it involves uncontrolled cell division. *Fibrosis* - Fibrosis implies the formation of excess **fibrous connective tissue**, leading to a stiff or thickened tissue, signifying abnormal tissue growth [4]. - It often results from chronic inflammation or injury, again reflecting **excessive tissue** formation [4]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 87-88. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 85-87. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 105-106. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 111-112.
Question 9: Which of the following type of collagen is present in healing and granulation tissue?
- A. Type II
- B. Type I
- C. Type III (Correct Answer)
- D. Type IV
Explanation: ***Type III*** - **Type III collagen** is prominently found in **granulation tissue** during the early stages of wound healing [1]. - It provides a **scaffold** for cellular migration and proliferation [2], contributing to the initial strength of the healing tissue. *Type II* - **Type II collagen** is the primary collagen type found in **cartilage**, particularly **hyaline cartilage**. - It is crucial for the **structural integrity** and resilience of articular surfaces, not typically in granulation tissue. *Type I* - **Type I collagen** is the most abundant collagen in the body, providing **tensile strength** to tissues like bone, skin, tendons, and ligaments. - While ultimately replacing type III collagen in mature scar tissue, it is **less prevalent in initial granulation tissue** compared to type III [1]. *Type IV* - **Type IV collagen** is a major component of **basement membranes**, forming a mesh-like network [3]. - It provides **structural support** and acts as a selective filter in tissues such as the kidneys and lungs, but not in healing granulation tissue. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 105-106. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, pp. 117-119. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. With Illustrations By, pp. 32-34.
Question 10: Which of the following substances is a growth factor that is capable of inducing all the steps necessary for angiogenesis?
- A. TGF -a
- B. PDGF
- C. EGF
- D. Basic fibroblast growth factor (Correct Answer)
Explanation: ***Basic fibroblast growth factor*** - **Basic fibroblast growth factor (bFGF or FGF2)** is a potent inducer of **angiogenesis**, promoting endothelial cell proliferation, migration, and tube formation. - It plays a crucial role in **wound healing** and **tumor growth** by stimulating the development of new blood vessels. *TGF-α* - **TGF-alpha** primarily acts as a **mitogen** for epithelial cells and fibroblasts, promoting cell growth and differentiation. - While it can indirectly influence angiogenesis, it does not directly induce all steps of the process like bFGF. *PDGF* - **Platelet-derived growth factor (PDGF)** is a mitogen for **fibroblasts, smooth muscle cells, and glial cells**, involved in wound healing and tissue remodeling. - Its primary role in angiogenesis is thought to be in the **stabilization of new vessels** by recruiting pericytes and smooth muscle cells, rather than initiating new vessel formation. *EGF* - **Epidermal growth factor (EGF)** primarily stimulates the **proliferation and differentiation of epidermal and epithelial cells**. - While it contributes to tissue repair and cell growth, its direct role in inducing all stages of angiogenesis is less prominent compared to bFGF.
Want unlimited practice?
Get full access to all questions, explanations, and performance tracking.
Start For Free