MLT GlobeBasic Pathology: Tissue repair & healing
59 Basic Pathology MCQs on Tissue repair & healing with answers and explanations.
Granulation tissue in a healing wound is defined chiefly by:
Granulation tissue is pink, granular tissue of new capillaries (angiogenesis) and fibroblasts in loose matrix. It is unrelated to a granuloma.
Which cells are permanent, having left the cell cycle and being unable to regenerate after injury?
Neurons and cardiac muscle cells are permanent cells; injury heals by gliosis or scarring. Hepatocytes and fibroblasts are stable cells that can re-enter the cycle.
Which factor supports rather than impairs wound healing?
Zinc is a cofactor for enzymes in collagen synthesis and cell proliferation. Diabetes, steroids, vitamin C deficiency and poor perfusion delay healing.
Which collagen type forms the network of basement membranes?
Type IV collagen is a non-fibrillar, sheet-forming collagen of basement membranes. Type I is in bone and scars, type II in cartilage, type III in reticular tissue.
Hepatocytes rarely divide normally but proliferate briskly after partial hepatectomy. They are classed as:
Stable cells are in G0 but can re-enter the cycle after injury. Labile cells (e.g., epithelia, marrow) divide continuously; neurons are permanent.
Which sequence correctly lists the phases of wound healing?
A clot forms first, inflammation clears debris, granulation tissue and epithelium proliferate, then collagen matures during remodelling.
Which healing complication results from excessive formation of repair components rather than deficient repair?
Keloids reflect excessive collagen deposition. Dehiscence, ulceration and delayed epithelialisation reflect inadequate repair.
Persistent vomiting, coughing or ileus after laparotomy raises abdominal pressure and may cause:
Mechanical stress on a young wound can split it open (dehiscence). The other options reflect excessive repair.
In a healing wound, the early matrix of fibrin, fibronectin and type III collagen is gradually replaced by a scar composed mainly of type:
Mature scar is dominated by type I collagen, which gives tensile strength. Type II is cartilage collagen; type IV forms basement membranes.
Compared with healing by first intention, healing by second intention is NOT associated with:
Secondary healing involves larger defects, more inflammation and much more granulation tissue, with marked contraction by myofibroblasts.
A large ulcer heals with abundant granulation tissue, wound contraction and a broad scar. This pattern is:
Extensive tissue loss requires combined regeneration and scarring with much granulation tissue: secondary intention. First intention involves clean, apposed edges.
Within 24 hours of a clean surgical incision, which cells appear at the margins moving toward the fibrin clot?
Neutrophils arrive first; macrophages largely replace them by day 3, and fibroblasts dominate later with granulation tissue.
A healing ulcer develops excess granulation tissue that bulges above the skin and prevents re-epithelialisation. This is:
Exuberant granulation tissue protrudes and blocks epithelial cover; it is treated by cautery or excision. Keloids and hypertrophic scars are collagen excesses.
A clean surgical incision whose edges are closed with sutures heals mainly by:
Primary union involves a narrow gap, little granulation tissue and a thin scar. Second intention applies to large open defects.
Which tissue has the greatest regenerative capacity after injury?
Labile tissues divide continuously from stem cells and regenerate readily. Cardiac muscle and neurons are permanent cells.
Clinically, the single most important local cause of delayed wound healing, which prolongs inflammation, is:
Infection sustains inflammation and adds tissue injury. Diabetes, malnutrition and steroids are systemic factors.
A tissue's ability to regenerate after injury is determined mainly by:
Labile, stable and permanent cells differ in proliferative capacity, which dictates regeneration versus scarring.
The amount of granulation tissue formed during repair depends chiefly on the:
Larger defects require more granulation tissue to fill them; the intensity of inflammation also contributes.
In granulation tissue, new blood vessels arise mainly by:
Angiogenesis supplies oxygen and nutrients for repair; endothelial cells sprout from existing vessels under VEGF and FGF stimulation.
After a myocardial infarction, the dead cardiac muscle is repaired mainly by:
Cardiomyocytes are permanent cells, so necrotic myocardium is replaced by granulation tissue and then a collagen scar.