IC2

• Chronic inflammation occurs when there is persistence of damaging stimulus or injury so that complete healing cannot occur.
• Chronic inflammation is characterized by infiltration of mononuclear cells, including macrophages, lymphocytes, and plasma cells.
• Chronic inflammation leads to tissue destruction and attempts at healing.
• Granulomatous inflammation is characterized by the formation of granulomas, composed of epithelioid cells, multinucleate giant cells, lymphocytes, and often seen in type 4 hypersensitivity reactions in which cell-mediated immunity is involved.
• Hyperaemia and Congestion are haemodynamic disorders (disorders of circulation).
• Peripheral Nerve Injury involves distal end degeneration, sprouts arising from severed axon, slow growth, haphazard growth, and loss of neurons that cannot be regenerated.
• Aortic valve stenosis is a pathology due to scarring.
• Fibrosis often refers to the abnormal deposition of collagen that occurs in internal organs in chronic diseases.
• Stomach outlet stenosis is a pathology due to scarring.
• Healing of Myocardial Infarct involves the healing of cardiomyocytes by fibrosis and compensation for loss of myocardium by hypertrophy of surviving myocardial fibres.
• Healing of a bone fracture involves initial bridging by hematoma, forming granulation tissues to form the woven bone "callus" remodeling with formation of cancellous bone, and increasing tensile strength.
• Constrictive pericarditis is a pathology due to scarring.
• Liver cirrhosis is a pathology due to scarring.
• Hyperaemia is defined as arterial vasodilation resulting in more blood in the blood vessels.
• Congestion is defined as venous outflow obstruction resulting in more blood in the blood vessels.
• Local factors that affect wound healing include infection, mechanical factors, foreign bodies, and the size, location, and type of wound.
• Hormones: Glucocorticoids have an anti-inflammatory effect and inhibit healing.
• Complications of wound healing include deficient scar formation, wound dehiscence (splitting open), ulceration, incisional hernias, and the formation of contractures following severe burns and chemical injury.
• Metabolic status: Diabetes (hyperglycemia) slows wound healing.
• Excessive scar formation can lead to hypertrophic scar or keloid, which is an overgrowth of scar tissue and overproduction of collagen.
• Dark skinned people are more affected by excessive scar formation.
• Excessive granulation tissue can protrude above surrounding skin and prevent reepithelialization.
• Age: Young people heal better and faster.
• Circulatory status: Insufficient blood supply impairs healing.
• Nutrition: Protein and vitamin C deficiency inhibit collagen synthesis.
• Systemic factors that affect wound healing include age, nutrition, metabolic status, and hormones.
• Generalised oedema can be caused by cardiac, renal, or hepatic causes.
• Haemorrhage can be caused by traumatic or spontaneous factors, and can be due to abnormal vessels or platelets.
• Congestion can be localised, in deep leg veins with blood clot, or generalised, as in congestive heart failure.
• Cardiac oedema is due to heart failure.
• Physiological hyperaemia is caused by nervous impulses and functional demands on muscles during exercise.
• Localised oedema can be caused by impaired venous drainage, venous occlusion due to thrombosis, increased vascular permeability and hyperaemia, inflammation, obstruction or destruction of lymphatics, and filariasis or cancer.
• Nephrotic syndrome is characterised by protein loss in urine due to glomerular disease, which results in reduced plasma oncotic pressure and activation of the renin-angiotensin-aldosterone system (kidney retains Na+ and water).
• Oedema is an excessive extravascular accumulation of fluid in interstitial tissues and body cavities.
• The primary causes of oedema are changes in Starling’s forces, including increased hydrostatic pressure, reduced oncotic (osmotic) pressure, increased endothelial permeability, lymphatic obstruction, and sodium and water retention.
• Pathological hyperaemia is associated with acute inflammation.
• Cancer, pneumonia, ischaemic heart disease, cerebrovascular disease, accidents, hypertensive diseases, kidney diseases, urinary tract infections, and other heart diseases are the top causes of death in Singapore.
• Septic emboli are a type of embolism that spread infection.
• Fat, air, and amniotic fluid are examples of liquid, gaseous, and solid types of embolisms respectively.
• Factors affecting the development of an infarct include the anatomy of the arterial blood supply, the rate of development of vascular occlusion, tissue vulnerability, and prior hypoxia.