回帖：Chapter 3 Hemodynamic Disorder
§1. Hyperemia and Congestion
1. Arterial hyperemia
(1)Definition: Increased volume of arterial inflow in an organ or tissue (hyperemia)
(2)Common types
·Physiologic: exercise → skeletal muscle
·Pathologic: at the foci of inflammation
·Hyperemia after reducing pressure
(3)Sequelae: Restore: if causes abated
Hemorrhage: hypertension, AS
2. Congestion
(1)Definition: Resulting from an isolate venous obstruction → accumulation of blood in veinlet and capillary
(2)Etiology
①Veins being pressed: Tumor → press local vein
pseudolobule → hepatic sinus
②Venous obstruction: thrombosis
③Heart failure: left → pulmonary congestion
right → hepatic congestion
(3)Lesions and results
①Hydrostatic pressure↑ → congestive edema, hemorrhage
②Chronic hypoxia → atrophy or degeneration, fibrosis, sclerosis
(4)Congestion of important organs
·Pulmonary congestion
①Cause: left heart failure
②Morphology: Gross: volume↑, weight↑, dark red, cut surface, consolidated
LM: Aalveolar septa: capillary engorged with blood
become thickened
fibrosis
Alveolar spaces: edema fluid
heart failure cells
hemorrhage
Brown induration: long period congestion, texture become solid and show brown appearance
·Hepatic congestion:
①Cause: right heart failure
②Morphology: Acute: Gross: enlarged, dark red
LM: The central vein and sinusoids: engorged with blood
Central hepatocyte: necrosis
Peripheral hepatocyte: fatty change
Chronic: Gross: nutmeg liver: cut surface shows zones of yellow alternating with zones of red, like nutmeg
LM: The central vein and sinusoids: distended with blood
Central hepatocyte: atrophy or necrosis
Peripheral hepatocyte: fatty change
Congestive bands among central vein
§2. Thrombosis
Definition: within living heart or blood vessel, blood coagulated (clotting) or some components clump form solid mass (thrombus)
1. Conditions and mechanism of thrombosis
(1)Endothelial injury
①Functions of Endothelium
·Antithrombotic properties: Screen function of intact endothelium
Antiplatelet adhering
Anticoagulants
Fibrinolytic
·Prothrombotic properties: Activate exogenous coagulation process
Promoting adhesion of platelet
Inhibiting fibrinolysis
②Functions of Platelets
·Adhesion and shape change
·Secretion (release reaction)
·Aggregation
③The common disease
·Endocardial injury: myocardial infarction, valvulitis
·Vascular injury: traumatic or inflammatory injury (vasculitis), AS → ulcerated plaques
·Hypoxia, shock, bacterial endotoxin → DIC → microthrombus
(2)Alteration in normal blood flow
①Refer to stasis or turbulence: Disrupt laminar flow and bring platelets into contact with endothelial cell
②Vein is the favored sites
·Venous valves → slow, turbulence
·Fugacious stasis
·Thinner wall → pressed easily
·Adherence increased (blood from capillary → vein)
(3)Blood hypercoagulability
①Inherited causes of hypercoagulability
·The most common cause: Mutation in the factor V gene
·Inherited lack of the anticoagulants: anti-thrombin, protein C, protein S
②Acquired causes of hypercoagulability
·Widely metastasis of malignant tumor
·Loss of blood: severe trauma, large area burn, operation