{"id":6564,"date":"2026-06-03T14:19:50","date_gmt":"2026-06-03T18:19:50","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/?post_type=chapter&p=6564"},"modified":"2026-06-09T15:22:58","modified_gmt":"2026-06-09T19:22:58","slug":"healing-and-tissue-repair","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/chapter\/healing-and-tissue-repair\/","title":{"raw":"Section 12:\u00a0 Healing and Tissue Repair","rendered":"Section 12:\u00a0 Healing and Tissue Repair"},"content":{"raw":"

Three Outcomes Following Acute Inflammation<\/strong><\/span><\/h3>\r\n\r\n\r\n\r\n\r\n\r\n
Resolution<\/strong><\/span><\/td>\r\nDamaged cells recover without dying<\/strong>.\u00a0 Full function is restored.<\/td>\r\n<\/tr>\r\n
Regeneration<\/strong><\/span><\/td>\r\nLost cells replaced by the same cell type<\/strong> via stem cell mitosis.\r\n\r\nMany epithelial<\/strong> cells<\/strong>, connective tissue cells<\/strong>, and liver cells<\/strong> are highly regenerative.<\/strong><\/td>\r\n<\/tr>\r\n
Replacement (Fibrosis)<\/strong><\/span><\/td>\r\nIn non-regenerative<\/strong> tissues (cardiac muscle, skeletal muscle, kidney cells, brain and spinal cord neurons, most cartilage<\/strong>) or large wounds, collagen and fibroblasts replace lost tissue forming scar tissue.<\/strong>\r\n\r\nThis process - fibrosis<\/strong> - involves permanent loss of functional tissue.<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

During healing:\u00a0 capillaries become less permeable, blood vessel diameter normalizes, WBCs inactivate, fibrin is dissolved, excess interstitial fluid is absorbed by lymph vessels, and the signs of inflammation - redness, warmth, swelling, pain - all diminish.<\/p>\r\n\r\n

Complications of Tissue Damage and Inflammation<\/strong><\/span><\/h3>\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
Chronic inflammation<\/strong><\/span><\/td>\r\nIf the irritant source is not removed, WBC activity perpetuates tissue destruction cycles and progressive fibrosis.<\/td>\r\n<\/tr>\r\n
Infection<\/strong><\/span><\/td>\r\nWounds exposed to the environment may be colonized by opportunistic microbes<\/strong> - even normal flora - causing further damage.<\/td>\r\n<\/tr>\r\n
Deep ulcers<\/strong><\/span><\/td>\r\nDamage to gastric mucosa allows stomach acid to erode<\/strong> underlying tissue, causing severe, prolonged inflammation, bleeding, necrosis, and fibrosis.<\/td>\r\n<\/tr>\r\n
Skeletal muscle spasms<\/strong><\/span><\/td>\r\nProtective response to pain during sprains<\/strong> and strains.<\/strong>\r\n\r\nIn bone fractures,<\/strong> spasms can shear tissue by forcing bone ends to move.\r\n\r\nNote:\u00a0 Temporary muscle spasms (e.g. charley horse) during excessive exercise are different in that the cause is thought to be not enough blood flow, cellular dehydration, and\/or electrolyte depletion.<\/td>\r\n<\/tr>\r\n
Peripheral and Central nerve damage<\/strong><\/span><\/td>\r\nPeriphery nerve damage can result in permanent or temporary\u00a0 loss of sensation (paresthesia),<\/strong> muscle weakness, or paralysis.\u00a0 Peripheral nerves may partially recover.\r\n\r\nBrain\/spinal cord neuronal loss is permanent;\u00a0 brain plasticity (remodelling) can sometimes occur to allow for partial recovery of some lost functions.<\/td>\r\n<\/tr>\r\n
Obstruction<\/strong><\/span><\/td>\r\nEsophageal swelling impairs swallowing;<\/strong> bronchiole\/bronchi swelling impairs breathing<\/strong> and gas exchange.<\/td>\r\n<\/tr>\r\n
Increased Intracranial Pressure (ICP)<\/strong><\/span><\/td>\r\nSwelling in the brain or cranial meninges can pinch off capillaries, reducing blood flow - potentially fatal.<\/td>\r\n<\/tr>\r\n
Myositis Ossificans<\/strong><\/span><\/td>\r\nCalcification<\/strong> within injured muscles (most commonly arm or thigh).\r\n\r\nRisk factors include deep contusions<\/strong> from contact sports.\r\n\r\nPrevention: prompt RICE<\/strong> therapy.<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n

Chronic Inflammation<\/strong><\/span><\/h3>\r\nChronic inflammation follows acute inflammation when the irritant is not fully removed - e.g., ongoing infection<\/strong>, smoking, pollutants, cancer, diabetes,<\/strong> or autoimmune diseases<\/strong> such as Rheumatoid Arthritis<\/strong> or Systemic Lupus Erythematosus (SLE)<\/strong>.\u00a0 Compared to acute inflammation, chronic inflammation features:\r\n
    \r\n \t
  • Less<\/strong> swelling and exudate<\/li>\r\n \t
  • More angiogenesis<\/strong> (new capillary formation)<\/li>\r\n \t
  • More<\/strong> lymphocytes, macrophages, and fibroblasts<\/li>\r\n \t
  • Continued tissue destruction<\/strong><\/li>\r\n \t
  • Increased collagen \u2192 fibrous scar tissue (fibrosis)<\/strong><\/li>\r\n \t
  • Possible granuloma<\/strong> formation (small masses of cells with a necrotic center covered by connective tissue) - seen in rheumatoid arthritis, osteoarthritis, around foreign objects, or at sites of chronic infection such as tuberculosis.<\/li>\r\n<\/ul>\r\n

    <\/h3>","rendered":"

    Three Outcomes Following Acute Inflammation<\/strong><\/span><\/h3>\n\n\n\n\n\n
    Resolution<\/strong><\/span><\/td>\nDamaged cells recover without dying<\/strong>.\u00a0 Full function is restored.<\/td>\n<\/tr>\n
    Regeneration<\/strong><\/span><\/td>\nLost cells replaced by the same cell type<\/strong> via stem cell mitosis.<\/p>\n

    Many epithelial<\/strong> cells<\/strong>, connective tissue cells<\/strong>, and liver cells<\/strong> are highly regenerative.<\/strong><\/td>\n<\/tr>\n

    Replacement (Fibrosis)<\/strong><\/span><\/td>\nIn non-regenerative<\/strong> tissues (cardiac muscle, skeletal muscle, kidney cells, brain and spinal cord neurons, most cartilage<\/strong>) or large wounds, collagen and fibroblasts replace lost tissue forming scar tissue.<\/strong><\/p>\n

    This process – fibrosis<\/strong> – involves permanent loss of functional tissue.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    During healing:\u00a0 capillaries become less permeable, blood vessel diameter normalizes, WBCs inactivate, fibrin is dissolved, excess interstitial fluid is absorbed by lymph vessels, and the signs of inflammation – redness, warmth, swelling, pain – all diminish.<\/p>\n

    Complications of Tissue Damage and Inflammation<\/strong><\/span><\/h3>\n\n\n\n\n\n\n\n\n\n\n
    Chronic inflammation<\/strong><\/span><\/td>\nIf the irritant source is not removed, WBC activity perpetuates tissue destruction cycles and progressive fibrosis.<\/td>\n<\/tr>\n
    Infection<\/strong><\/span><\/td>\nWounds exposed to the environment may be colonized by opportunistic microbes<\/strong> – even normal flora – causing further damage.<\/td>\n<\/tr>\n
    Deep ulcers<\/strong><\/span><\/td>\nDamage to gastric mucosa allows stomach acid to erode<\/strong> underlying tissue, causing severe, prolonged inflammation, bleeding, necrosis, and fibrosis.<\/td>\n<\/tr>\n
    Skeletal muscle spasms<\/strong><\/span><\/td>\nProtective response to pain during sprains<\/strong> and strains.<\/strong><\/p>\n

    In bone fractures,<\/strong> spasms can shear tissue by forcing bone ends to move.<\/p>\n

    Note:\u00a0 Temporary muscle spasms (e.g. charley horse) during excessive exercise are different in that the cause is thought to be not enough blood flow, cellular dehydration, and\/or electrolyte depletion.<\/td>\n<\/tr>\n

    Peripheral and Central nerve damage<\/strong><\/span><\/td>\nPeriphery nerve damage can result in permanent or temporary\u00a0 loss of sensation (paresthesia),<\/strong> muscle weakness, or paralysis.\u00a0 Peripheral nerves may partially recover.<\/p>\n

    Brain\/spinal cord neuronal loss is permanent;\u00a0 brain plasticity (remodelling) can sometimes occur to allow for partial recovery of some lost functions.<\/td>\n<\/tr>\n

    Obstruction<\/strong><\/span><\/td>\nEsophageal swelling impairs swallowing;<\/strong> bronchiole\/bronchi swelling impairs breathing<\/strong> and gas exchange.<\/td>\n<\/tr>\n
    Increased Intracranial Pressure (ICP)<\/strong><\/span><\/td>\nSwelling in the brain or cranial meninges can pinch off capillaries, reducing blood flow – potentially fatal.<\/td>\n<\/tr>\n
    Myositis Ossificans<\/strong><\/span><\/td>\nCalcification<\/strong> within injured muscles (most commonly arm or thigh).<\/p>\n

    Risk factors include deep contusions<\/strong> from contact sports.<\/p>\n

    Prevention: prompt RICE<\/strong> therapy.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Chronic Inflammation<\/strong><\/span><\/h3>\n

    Chronic inflammation follows acute inflammation when the irritant is not fully removed – e.g., ongoing infection<\/strong>, smoking, pollutants, cancer, diabetes,<\/strong> or autoimmune diseases<\/strong> such as Rheumatoid Arthritis<\/strong> or Systemic Lupus Erythematosus (SLE)<\/strong>.\u00a0 Compared to acute inflammation, chronic inflammation features:<\/p>\n

      \n
    • Less<\/strong> swelling and exudate<\/li>\n
    • More angiogenesis<\/strong> (new capillary formation)<\/li>\n
    • More<\/strong> lymphocytes, macrophages, and fibroblasts<\/li>\n
    • Continued tissue destruction<\/strong><\/li>\n
    • Increased collagen \u2192 fibrous scar tissue (fibrosis)<\/strong><\/li>\n
    • Possible granuloma<\/strong> formation (small masses of cells with a necrotic center covered by connective tissue) – seen in rheumatoid arthritis, osteoarthritis, around foreign objects, or at sites of chronic infection such as tuberculosis.<\/li>\n<\/ul>\n

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