Welcome to your 4. 🩹 Tissue Healing, Regeneration, Scarring & ECM Arena
1.
A regenerating epithelial cell has reached the point at which it is preparing to commit to DNA synthesis. Which regulatory complex most directly promotes this transition?
2.
A 67-year-old man sustains an acute myocardial infarction with loss of a large number of cardiac myocytes. Healing occurs predominantly by scar formation. Which biological property of the injured cells best explains this pattern?
3.
A patient undergoes partial hepatectomy for a localized liver lesion. The remaining hepatocytes are initially quiescent but subsequently begin proliferating in response to growth signals. Which feature of these cells allows this response?
4.
A patient with gastrointestinal mucosal injury rapidly replaces lost epithelial cells after the damaging stimulus is removed. Which property of this tissue most strongly supports such recovery?
5.
A histological section from a healing wound shows excessive granulation tissue projecting above the level of the surrounding epidermis. Which consequence is most likely if this abnormality persists?
6.
A 40-year-old woman has a deep wound. Histology shows fibroblast proliferation and increasing deposition of collagen in the damaged area. Which sequence best explains how this process contributes to healing?
7.
A growth factor binds to its receptor on a fibroblast and activates RAS and downstream MAP kinase signaling. The final effect is increased expression of genes promoting cellular proliferation. Which receptor class most likely initiated this signaling pathway?
8.
A resting hepatocyte receives growth-factor stimulation following tissue loss. Before DNA synthesis begins, the cell increases protein synthesis and prepares for replication. Which phase is it entering?
9.
A wound across the anterior surface of a joint heals with marked shortening of the scar and progressive restriction of movement. Which cellular event contributed most directly to this complication?
10.
A fibroblast exposed to TGF-β increases production of extracellular matrix proteins. Unlike many other growth factors involved in repair, TGF-β transmits its signal primarily through which pathway?
11.
A biopsy from a healing skin wound shows newly formed vascular channels developing from pre-existing vessels. Endothelial cells have migrated into the injured area and are beginning to form vascular tubes. Which event is most important for completing this process?
12.
A 45-year-old man is reviewed several weeks after abdominal surgery. His wound has become paler and firmer compared with the early postoperative period. Which process most directly accounts for this change?
13.
A growth factor released during tissue repair stimulates proliferation and migration of several epithelial cell types by binding to the MET receptor. Which mediator is responsible?
14.
A patient develops extensive tissue destruction following a severe injury. Although surviving parenchymal cells retain the ability to proliferate, normal tissue architecture is not restored and fibrosis occurs instead. Which change most strongly explains this outcome?
15.
A 58-year-old man undergoes abdominal surgery. On postoperative day 6, the wound edges separate after a bout of severe coughing. Histology shows inadequate connective-tissue deposition at the healing site. Which abnormality of repair best explains this complication?
16.
A 58-year-old woman has a deep skin wound with extensive destruction of both epithelial cells and supporting stromal tissue. During healing, fibroblasts migrate into the damaged area and produce extracellular matrix. Which outcome is most likely?
17.
A pathology student compares healing in intestinal mucosa, liver and myocardium after injury. Which combination correctly matches their relative proliferative behaviour?
18.
A 64-year-old man with peripheral vascular disease develops a chronic wound over his foot. There is no major nutritional deficiency, but healing remains slow. Which mechanism most directly contributes to impaired repair?
19.
A 60-year-old man develops extensive fibrosis after severe tissue injury. Histological examination shows marked extracellular matrix deposition by activated fibroblasts. Which mediator is most closely associated with this response?
20.
A 50-year-old man sustains severe tissue injury. In one region, surviving cells proliferate along an intact stromal framework. In another region, the supporting framework is destroyed and fibroblasts deposit collagen. Which interpretation best explains these two outcomes?
21.
A patient has a deep wound containing a retained foreign material. The wound remains inflamed and fails to progress normally toward scar maturation. Which mechanism best explains the delayed repair?
22.
A researcher observes that matrix degradation in a healing wound decreases despite continued production of matrix metalloproteinases. Which endogenous molecules most directly account for this effect?
23.
A cell exposed to a mitogenic growth factor activates a regulatory complex that promotes progression through early G1. Which complex is most closely involved?
24.
A 55-year-old woman with poorly controlled diabetes develops delayed healing after minor foot trauma. The wound also becomes secondarily infected. Which combination best explains the impaired repair?
25.
A proliferating cell has duplicated its DNA successfully and is preparing to enter mitosis. Activation of which regulatory complex is most directly associated with this transition?
26.
A mature scar is compared with the granulation tissue from which it developed. Which finding most strongly indicates successful progression to the mature stage?
27.
A healing wound initially appears red and highly vascular. Several weeks later, the scar is less vascular and more collagenous. Which change best explains the reduced vascularity?
28.
A patient with a large tissue defect is forming new capillaries within the healing area. Local cells release a mediator that acts strongly on vascular endothelial cells. Which mediator is most responsible for this response?
29.
A fibroblast migrating through a healing wound must attach to extracellular matrix and respond to signals from its surrounding environment. Which ECM property best explains this regulatory role?
30.
A tissue is injured, but surviving cells retain proliferative capacity and the supporting extracellular framework remains largely preserved. Growth-factor signalling activates these cells. Which sequence best represents the expected regenerative response?
31.
A proliferating fibroblast has completed DNA replication. Before chromosome segregation occurs, the cell checks whether replication has been completed appropriately. Which phase corresponds to this period?
32.
A healing wound initially appears red and soft but becomes progressively pale and firm over several weeks. Which combination of changes best accounts for this transition?
33.
A biopsy from a healing surgical wound shows numerous thin-walled capillaries, proliferating fibroblasts and loose extracellular matrix. Which stage of healing is represented by this finding?
34.
A skin wound shows fibroblast proliferation and matrix deposition under the influence of several growth factors. One mediator promotes epithelial proliferation by acting through the same receptor used by epidermal growth factor. Which mediator is being described?
35.
During repair, extracellular matrix proteins bind certain growth factors and maintain them near cells participating in healing. What is the main significance of this property?
36.
A healing wound is repeatedly subjected to tension because of excessive movement at the injured site. Despite adequate nutrition and absence of infection, repair is delayed. Which explanation is most appropriate?
37.
A pathologist compares two extracellular matrix compartments. One is present between connective-tissue cells, while the other forms a specialized sheet beneath epithelium. Which component is characteristically associated with the second compartment?
38.
A 32-year-old man sustains a shallow abrasion over his forearm. The surface epithelium is damaged, but the underlying extracellular matrix framework remains intact. After several days, the area returns to near-normal structure without a visible scar. Which factor best explains this outcome?
39.
During scar maturation, extracellular matrix must be continuously reorganized. If matrix metalloproteinase activity greatly exceeds its normal regulation, which change would be expected?
40.
A cell in a healing tissue develops DNA damage before replication. A regulatory protein induces cell-cycle arrest so that damaged DNA is not immediately propagated. Which protein is most important in this response?
