Introduction to Pathology Unit 4 Study set (AAMI)

Causes of thrombosis

- Injury to the blood vessel by trauma, degeneration, or inflammation - Slow rate of blood flow - Disease of the blood itself - Alterations in blood composition

Effects of Ischemia

- decrease in blood flow to the tissues. - decrease in nutrients - may cause necrosis, which may be irreversible.

Organization

A conversion of the thrombus into a fibrous plug.

Ischemia

A decrease in blood flow to an area resulting from the blockage (obstruction) in the vascular system.

Ischemia

A decrease in the arterial blood flow or supply to a given part of the body.

Hematoma

A localized collection of extravascular blood; a circumscribed tumor-like swelling filled with blood (blood blister).

Ecchymosis

A purple or bluish area on the skin or mucous membrane (bruise).

Propagate

A small thrombi that can extend down the long axis of the vessel, increasing in thickness until the vessel is totally occluded.

Hemothorax

Accumulation of blood in the thoracic cavity.

Abscess

Can put pressure on vessels also leading to a decrease in the flow of embalming fluids.

Obstructive Thrombus

Complete blockage of a vessel

Purpura

Purple colored spots and patches that occur on the skin, on organs, and membranes including the lining of the mouth.

Edema in the tissues predisposes to ______ decomposition.

Rapid

Fat Embolism

Results from severe trauma or crushing injuries to bone which allows the fat in the bone marrow to enter the veins in form of fat globules.

Anascarca

Severe generalized massive edema

Dropsy

Severe generalized massive edema.

Petechiae

Small pinpoint hemorrhages found in the skin, mucous membrane or eye sclera.

Passive hyperemia (congestion)

decrease of venous flow; often associated with hydrostatic edema

Vascular Disease

increased vascular fragility i.e. infections, drug reactions, poor vascular support

Animal Parasites

numerous parasitic worms find their way into the blood stream.

Infarction or ischemic necrosis

As a result of ischemia, the area of tissue which was deprived of its blood supply dies.

Melena/Melenic

Black or dark brown, "black tarry stool" sticky intestinal material/feces (contains digested blood from the upper gastrointestinal bleeding) looks like chocolate syrup.

Causes of Ischemia

Blood Clot (thrombus, embolus). Hypotension (decreased blood pressure). Changes in blood vessels (atherosclerosis-a thickening in the vascular walls)

Thrombus

Blood clot

Hematuria

Blood in urine caused by: infection; tumor; trauma and kidney stones.

Hemorrhage

Can actually short circuit the flow of embalming fluid through out the body.

Local Passive Hyperemia

Caused by an obstruction of a vein due to a thrombus, embolus, thickening of the vessel walls or external pressure. The affected area will appear swollen, cool to the touch, and will be dark reddish-blue in color.

Generalized

Caused by an obstruction of blood flow through the heart, leading to inadequate circulation. The results of this are known as hypostatic congestion.

Parietal Thrombus

Causes a partial occlusion of a vessel

Recanalization

Channels start to develop within the fibrous plug restoring partial blood flow.

Necrosis

Death of tissue

May cause emaciation and dehydration of various body areas if the blood supply had been lessened for an extended period of time.

Diminished Circulation

Foreign Bodies

Dirt or even pellets from a shotgun blast can enter the vessels and become emboli.

In areas visible during viewing

Discoloration

Air or gas

Due to the entrance of air into the veins either during surgical procedure or through hypodermic injections

Dissolution

Enzymes specific for this purpose (fibrinolytic proteins) engulf and dissolve the clot.

Ascites

Excess fluid in the peritoneal (abdominal cavity)

Exsanguination

Excessive loss of blood due to internal or external hemorrhage.

Epistaxis

Hemorrhage from the nose; nosebleed

Active or Arterial Hyperemia

Hyperemia as a result of an increase in the arterial flow to a body part.

Passive or Venous Hyperemia / Congestion

Hyperemia as the result of a decrease in the venous drainage from a body part.

Spread of infection

Infectious emboli may result in system infection.

Trauma

Injury to blood vessels or soft tissue resulting in bleeding.

Embolus causes:

Ischemia Infarction/Ischemic Necrosis Spread of Infection Spread of tumor cells Necrosis Tumor Embolus

Consequences of Thrombi

Ischemia, passive hyperemia, gangrene, infarction

Tumor Cells

Malignant tumors that may become detached and enter circulation.

Edema

May be either localized such as in inflammation, or generalized, as in cardiac failure.

Fragments of thrombi

Most common type of emboli.

Ischemia

Reduction of blood flow resulting in lack of oxygen and nutrients to the tissue.

Active / Arterial Pathological Hyperemia / Congestion

Results from increased arterial flow as a bodily reaction to injury, such as inflammation.

Active / Arterial Physiological Hyperemia / Congestion

Results from increased arterial flow for natural reasons, such as in blushing, where no lesion exists. Presence of extra blood in the muscles of the body during exercise.

Tumor Embolus

The escape of blood from the blood vascular system. Anytime that blood leaves a vessel, it can be described as hemorrhage.

Thrombosis

The formation of a solid mass or "blood clot" within the heart or vessels of the body.

Hemoptysis

The presence of blood in the sputum; coughing up blood caused by a hemorrhage in the lungs; or TB.

Hematemesis

The presence of blood in the vomit caused by a hemorrhage in the upper GI tract.

Causes of Hemorrhage

Trauma, vascular disease, blood disorder, and hypertension.

Spread of tumor cells

Tumor cells may travel to distant sites and cause metastatic tumor growth.

Location of thrombi

Arteries Veins - especially the legs Heart Aorta

Hypertension

Elevated blood pressure resulting in disruption of the blood vessel wall. i.e. hemorrhage, stroke.

Blood Disorder

Increases the tendency to bleed, disorders of platelets (thrombocytopenia) or defects in clotting factors (coagulation) hemophilia

A prolonged ischemic condition can lead to localized necrosis also known as?

Infarction or ischemic necrosis

Infarction

Necrosis of tissue due to decrease in blood supply.

Septic emboli

Occurs in bacterial endocarditis and when bacterial colonies either are growing in veins or gain access to the circulation.

Embolize

Thrombus breaks off or dislodges and travels to different sites in the blood vascular system.

Embolism

The condition of a solid, liquid or gaseous mass carried in the blood stream until it becomes lodged somewhere else in the circulatory system.

Hypostatic congestion

The settling of blood to dependent regions

Emboli (Embolus)

Thrombi that breaks off and circulates in the blood stream also known as thromboembolus.

Diminished Circulation

Thrombosis, embolisms, tumors and various other arterial disorders can result in decreased flow of embalming fluids.