Hypermia and Congestion
المؤلف:
Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. ; Bedane,A. and Desta, A
المصدر:
General Pathology
الجزء والصفحة:
23-2-2016
1257
Hypermia and Congestion
Definition: Both of them can be defined as a local increase in volume of blood in a particular tissue.
Hypermia
- is an active process resulting from an increased inflow of blood into a tissue because of arteriolar vasodilation.
- commonly occurs in exercising skeletal muscle or acute inflammation.
- Affected tissue becomes red as there is engorgement with oxygenated blood.
Congestion
- is a passive process resulting from impaired outflow of blood from a tissue.
- occurs systemically as in cardiac failure or locally as in isolated venous obstruction.
- Affected tissue appears blue-red due to accumulation of deoxygenated blood.
- In long-standing congestion (also called chronic passive congestion states), poorly oxygenated blood causes hypoxia → results in parenchyma cell degeneration or cell death.
a) Pulmonary congestion
Cut surface: hemorrhagic & wet.
1. Acute pulmonary congestion:
- Alveolar capillaries engorged with blood
- Septal edema
2. Chronic pulmonary congestion:
- Thickened & fibrotic septa
- Alveolar spaces contain hemosiderin-laden macrophages resulting in an appearance termed brown indurations.
- Can result in pulmonary hypertension.
b) Hepatic congestion
1) Acute hepatic congestion:
- Central vein & sinusoids are distended
- There may be even central hepatocyte degeneration.
- Peripheral hepatocytes better oxygenated & develop only fatty changes.
2) Chronic passive congestion of liver:
- Central lobules grossly depressed because of loss of cells & appear red brown (nutmeg liver).
- Hemosiderin laden macrophages
- In longstanding hepatic congestion, commonly associated with cardiac failure, there is a grossly evident hepatic fibrosis called cardiac cirrhosis
References
Bezabeh ,M. ; Tesfaye,A.; Ergicho, B.; Erke, M.; Mengistu, S. and Bedane,A.; Desta, A.(2004). General Pathology. Jimma University, Gondar University Haramaya University, Dedub University.
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