The gastrointestinal mucosa is congested after eating, the skeletal muscles are congested by exercise, and the pregnant uterus is congested.

Inflammatory hyperemia, post-decompression hyperemia (reflexive dilation of arterioles)

The size increases slightly. If it occurs on the body surface, the local color will be bright red and the temperature will increase.

Local arteriole and capillary congestion

Usually no adverse consequences. On the basis of diseased blood vessels, blood vessel rupture may occur.

Tumors and pregnant uterus compress veins, and intestinal volvulus compresses mesenteric veins.

Venous thrombosis, tumor thrombus, etc.

Left heart failure causes pulmonary congestion Right heart failure causes systemic circulation congestion

naked eye

under the mirror

Short-term congestion with little consequences Prolonged congestion can lead to atrophy, degeneration (reversible damage) and death of parenchymal cells Interstitial fibrous tissue hyperplasia, reticular cell collagenization, and congestion sclerosis

acute pulmonary congestion

chronic pulmonary congestion

acute liver congestion

chronic liver congestion

endothelial cell anticoagulation

Procoagulant effect of endothelial cells

platelet activation

Location: heart valves with fast blood flow, intracardiac chambers, intraarteries and the starting point of continuous thrombus

Naked eye: gray-white nodules, rough surface

Microscopically: It is mainly composed of platelets and a small amount of fibrin, also known as platelet thrombus or precipitated thrombus.

Site: Persistent thrombosis body

Under the microscope: light red structureless coral-like platelet trabeculae

Naked eye: Gray-white layered structure of alternating platelets and red blood cells

Location: Mainly found in veins, tail of continuous thrombus

Under the microscope: The fibrin mesh is filled with blood cells, mainly red blood cells and a small amount of white blood cells.

Naked eyes: Dark red, not sticky with blood vessels, easy to fall off and form thrombus.

Location: Mainly in capillaries, also known as microthrombus, common in DIC

Under the microscope: composed of eosinophilic homogeneous fibrin, also known as fibrinous thrombus

Incomplete obstruction causes ischemia and parenchymal cell atrophy

Infarction occurs when there is complete obstruction and no effective collateral circulation.

No effective collateral circulation, causing local congestion, edema, hemorrhage and necrosis

When collateral circulation is abundant, no obvious symptoms are caused

Medium and small emboli: usually no obvious symptoms

With large emboli, the patient suddenly develops dyspnea, shock, and sudden death.

The emboli are small but numerous: embolism occurs in most small branches and sudden death occurs.

mechanism:

Most emboli originate from the left heart Main parts: lower limbs, brain, intestines, kidneys and spleen

Depends on how the organ is vascularized

For example, spleen, kidney, and lung infarcts are cone-shaped. myocardial infarction map Intestinal infarction segmental shape

Depends on type of necrosis

Depends on blood content Less, white infarct Multiple, red infarcts (hemorrhagic infarcts)

It occurs in solid organs with dense tissue structure and insufficient collateral circulation, such as spleen, kidney, heart and brain tissue.

Occurrence conditions

Common types

Caused by emboli containing bacteria that block blood vessels