Hemodynamics - Hyperemia

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DISORDERS OF PERFUSIONDr. Jyothi Reshma STutorDept of PathologyHYPEREMIA, CONGESTION, HEMORRHAGE

HEMODYNAMICS - 2

ACTIVE HYPEREMIA Active hyperemia : increased supply of blood from the arterial system

Physiologic response to increased functional demand

Eg: heart and skeletal muscle during exercise, inflammation

Neurogenic and hormonal influences

Reactive hyperemia - temporary interruption of blood supply (ischemia) - histamine

PASSIVE HYPEREMIAPassive hyperemia or congestion : impaired exit of blood through venous pathways

Increased hydrostatic pressure - edema.

Lack of blood flow - chronic hypoxia - ischemic tissue injury and scarring.

Capillary rupture - small hemorrhages - catabolism of extravasated red cells - hemosiderin-laden macrophages - Chronic venous congestion (CVC)

Consequences of Impaired Venous OutflowIncreased intravascular pressure StasisHAEMORRHAGENECROSISCONGESTIONOEDEMAHYPOXIAFIBROSISCapillary ruptureAcuteChronic

CVC LUNGEnlarged, heavyFibrosis + iron = firm brown lung - brown induration

CVC LUNG

Alveolar congestionIntra-alveolar hemorrhageHemosiderin-laden macrophages in the lung - congestive heart failure heart failure cells

LIVER - ORGANIZATION

CVC LIVER

Distension - central vein and sinusoids Centrilobular area is at the distal end of the hepatic blood supply - ischemic necrosis

Periportal hepatocytes - better oxygenated because of proximity to hepatic arterioles fatty change.

CVC LIVER NUTMEG LIVER

Dark foci of centrilobular congestion surrounded by paler zones of unaffected peripheral portions of the lobules

CVC LIVER M/S

Centrilobular hemorrhage

Hemosiderin-laden macrophages

Hepatocytedropout and necrosis

CVC SPLEENGross : enlarged and tense

M/s: Diffuse splenic fibrosis - iron-containing, fibrotic and calcified foci of old hemorrhage Gamna-Gandy bodies

Excessive functional activityhypersplenism - hematologic abnormalities - thrombocytopenia

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CVC SPLEEN

Gamna-Gandy bodies

SUMMARYGROSSMICROSCOPY

EnlargedReddish blue - cyanosedC/s : oozing of bloodFirm : fibrosisCapsule : thickened

Capillary (sinusoids) : dilated , congested bloodSepta : thickenedFibrotic bandsHemosiderin laden macrophages : special names (lung, spleen)

PATHOGENESIS

HEMORRHAGE

Escape of blood from the vasculature into surrounding tissues, a hollow organ or body cavity, or to the outsideETIOLOGY, TYPES, CONSEQUENCES

HEMATOMALocalized hemorrhage - within a tissue or organ

PETECHIAE

Pinpoint hemorrhages - 1cmPurple green yellow (progressive oxidation of bilirubin released from the hemoglobin of degraded erythrocytes)

Hemothorax, hemopericardium, hemarthrosis, hemoperitoneum

COMPREHENSION QUESTIONSA 40-year-old woman dies after a long history of an illness characterized by dyspnea, orthopnea, hepatomegaly, distended neck veins, and peripheral edema. The cut surface of the liver as it appears at autopsy is shown in the first panel. The second panel shows the microscopic appearance of the liver. What is the most likely cause of these findings?

A 36-year-old man dies during cardiac surgery. He had a history of long-standing rheumatic heart disease with mitral stenosis. At autopsy, the pathologist reports findings consistent with mitral stenosis and noted the presence of heart failure cells. This finding results from

(A) activation of the coagulation cascade.(B) chronic passive congestion of the lungs.(C) hypoxic myocardial injury.(D) myocardial hyperemia.

EXAMPLE OF

ECCHYMOSIS

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