Disorders of blood circulation (hyperemia, hemorrhages, ischemia, interstitial fluid content derangement)
Blood flow adequacy is ensured by: o Adequate heart function; o Vessel wall integrity; o Balance of coagulative and anticoagulative blood systems.
3 groups of blood circulation disorders o o o Disorders of blood filling (hyperemia, ischemia) Vessel wall permeability derangement (hemorrhages, bleeding, plasmorrhagia) Blood rheological properties derangement (stasis, thrombosis, embolism, sludge-phenomenon, DICsyndrome)
HYPEREMIA
Arterial (active) hyperemia Process essence: increase of an organ blood filling due to excessive flow of arterial blood. Blood outflow is not changed. According to prevalence: General and local
General arterial hyperemia o o Erythremia – increase of erythrocytes quantity Plethora – increase of circulating blood volume
Local arterial hyperemia: o o Physiologic congestion (in case of emotional reactions, work hyperemia) Pathologic
Types of pathologic local congestions: o o o Angioneurotic Vacate (vacuum) Due to arterial-venous fistula Collateral Due to inflammation Hyperemia following anemia
Anatomical manifestations: o o o Reddening of skin, mucous membranes of tissues and organs Hypertension (arterial) Rise of temperature
Significance: o o o More often has a compensatory-adaptive character There is no structural reconfiguration in organs Outcome is favourable
Venous (passive) hyperemia Process essence: Increased blood filling of the tissue/organ due to obstructed outflow of venous blood.
Venous hyperemia o o According to prevalence: general and local According to the course: acute and chronic
Causes of general venous hyperemia: o o Acute cardiac or cardiopulmonary decompensation (myocardial infarction, acute myocarditis, pneumothorax, asphyxia) Chronic cardiac insufficiency (chronic ischemic heart disease, heart troubles, chronic myocarditis, emphysema of lungs and pneumosclerosis)
Anatomical signs: o o o Organs are enlarged Organs are solid (consolidated) Tissue is of dark-red color with cyanotic tint
Morphologic changes in tissues: o o o Acute course: Hyperemia of veins Stasis Edema of stroma Diapedesis of erythrocytes Dystrophy of parenchyma
Chronic course: o o o Edema (permeability increase due to hypoxia) Diapedesis of erythrocytes Dystrophy of parenchyma Necrosis Stroma expanding (overgrowth) Organ sclerosis
Consequences: o o Acute course – the process is irreversible Chronic course: - parenchyma atrophy - stroma sclerosis - organ cirrhosis
Organopathology: o o “Nutmeg liver” “Brown induration” of the lungs “Cyanotic induration” of the spleen “Cyanotic induration” of the kidneys
«Nutmeg liver» Маcro: liver is enlarged, solid, looks like nutmeg on incision Мicrо: the central veins are full-blooded (plethoric), there are hemorrhages and necrosis of hepatocytes in the lobules centers, fatty degeneration of peripheral hepatocytes
Brown induration of lungs Маcrо: lungs are enlarged, solid, of brown color Мicrо: in the lumen of alveoli – hemosiderin, growth of connective tissue in alveolar septum
Cyanotic induration of the spleen and kidney Маcrо: organs are enlarged, solid, of cyanotic color Мicrо: plethora of veins, growth of connective tissue in the stroma of organs
Local venous plethora. Causes: - venous congestion (thrombus) - vein compression (tumor, scarring, fluid) - collateral venous hyperemia (by opening of portocaval shunts)
In case of local venous hyperemia we see the same anatomical changes, as during the common venous plethora, but in one (single) organ.
Ischemia o Process essence: decrease of organ or tissue blood supply due to insufficient arterial flow
Ischemia (anemia): General (acute or chronic) o Local (acute and chronic) o
Ischemia types according to development mechanism: o o Angiospastic – vasospasm (irritation of vasoconstrictive nerves) Obstruction ischemia – arterial occlusion by thrombus, embolus Compression ischemia – arterial compression from the outside (tumor, tourniquet, commissure) Redistributive – blood redistribution to the zone of arterial hyperemia
Morphological signs: o o Organ size reduction; Flabby consistency; Paleness; Wrinkled capsule.
Ischemia outcomes o o o Without consequences in case of angiospastic form Degeneration, necrosis (infarction) – in case of acute form Atrophy, sclerosis – in case of chronic form
Bleeding (hemorrhage) o Process essence: blood o Internal, external. outflow from the cardiac cavities or (and) vessels lumen outward the body or into the tissues and internal cavities.
External bleedings: o o o Hemoptysis (haemoptoe) Nasal hemorrhage (epistaxis) Blood vomiting (haematomesis) Bloody stools (melena) Uterine bleeding (metrorrhagia)
Internal bleedings: o o Hemopericardium Hemothorax Hemoperitoneum Hemarthrosis
Bleeding mechanisms o Vascular wall rupture (haemorrhagia per rhexin) o o Vascular wall erosion (haemorrhagia per diabrosin) Diapedesis of erythrocytes (haemorrhagia per diapedesin)
Wall rupture: o o Aortic medianecrosis Syphilitic mesaortitis Ruptures of the enlarged liver and spleen Cardiac, aortic, cerebral arteries aneurism
Wall erosion: o o In In the inflammation foci ulcerations tubal pregnancy necrosis zone
Diapedesis: o o o Hypertension Systemic vasculitis Infections (typhus, scarlet fever, sepsis) Diseases of hemopoietic organs DIC - syndrome Hypoxic states
Hemorrhage: o o o Blood accumulation in tissues Petechia Bruises Hemorrhagic infiltration Hematoma
Outcomes of hemorrhages o o Resorption (decomposition) Organization (encapsulation) Cyst formation Suppuration
Consequences of bleedings and hemorrhages depend on: o o o Hemorrhage speed Hemorrhage volume Process localization
Interstitial fluid content derangements o o Transsudate – hydropic fluid Edema – fluid accumulation in tissues Dropsy – fluid accumulation in cavities Anasarca, hydrothorax, hydropericardium, ascites, hydrocephalus
Types of edema: 1. Local edema: is caused by the local derangement of interstitial fluid metabolism 2. General edema (anasarca): caused by retention of natrium ions and water in the organism
Local edema o Allergic o As a result of venous congestion o As a result of lymphatic congestion
General edema o o o Cardiac edema Hypoproteinemic edema Renal edema Pulmonary edema Brain (cerebral) edema Serous cavities edema
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