Blood Vessel and Heart

What is cardiovascular disease (CVD)?

An umbrella term for disorders of the heart and blood vessels.

Why are cardiovascular diseases dangerous?

They can reduce blood flow, oxygen, and nutrients to tissues.

What are three major causes of impaired perfusion?

Blood vessel obstruction, vessel rupture, or failure of the heart to pump.

Which organs are especially vulnerable to poor perfusion?

Brain, heart, and kidneys.

What is the most common cause of CVD?

Atherosclerosis.

What are major CVD risk factors?

Hypertension, diabetes mellitus, hyperlipidemia, and smoking.

What is the main function of arteries?

Carry blood away from the heart.

What type of blood do arteries usually carry?

Oxygen-rich blood.

What is the main function of veins?

Carry blood toward the heart.

What type of blood do veins usually carry?

Oxygen-poor blood.

What do pulmonary arteries carry?

Oxygen-poor blood.

What do pulmonary veins carry?

Oxygen-rich blood.

What are the three layers of a blood vessel?

Intima, media, and adventitia.

What does the brachiocephalic trunk divide into?

Right carotid artery and right subclavian artery.

What is edema?

Excess fluid in interstitial tissues.

What is an effusion?

Excess fluid in a body cavity.

What is hemorrhage?

Loss of blood from the vascular system.

What is thrombosis?

Formation of a local blood clot that occludes a vessel.

What is embolism?

Blockage of a vessel by material traveling through the bloodstream.

What is infarction?

Tissue necrosis caused by loss of blood supply.

What is shock?

A severe drop in blood pressure causing tissue hypoperfusion.

What is DVT?

A thrombus in a deep vein.

Where can a venous thrombus travel?

To the lungs, causing pulmonary embolism.

What can an arterial thrombus cause?

Stroke, myocardial infarction, or other tissue infarction.

How does increased hydrostatic pressure cause edema?

It pushes more fluid out of blood vessels.

What can increase hydrostatic pressure?

Heart failure or venous obstruction.

How does low plasma oncotic pressure cause edema?

Less protein is available to keep fluid in blood vessels.

What can reduce plasma oncotic pressure?

Kidney disease, liver disease, or malnutrition.

How does lymphatic obstruction cause edema?

It prevents normal drainage of tissue fluid.

How does sodium and water retention cause edema?

It increases total body fluid volume.

How does inflammation cause edema?

It increases vascular permeability.

What is pitting edema?

A depression remains after pressure is applied.

Is lymphedema usually pitting or non-pitting?

Usually non-pitting.

What percentage of liver blood flow comes from the portal vein?

About 75%.

What can severe or rapid hemorrhage cause?

Shock and death.

Where can hemorrhage occur?

Externally, internally, or within tissues.

What is a hematoma?

A localized collection of blood in tissue.

What determines how serious hemorrhage is?

Amount lost, rate of loss, age, and bleeding location.

Why is bleeding inside the skull dangerous?

It can rapidly increase intracranial pressure.

What are petechiae?

Tiny 1-2 mm hemorrhages.

What can cause petechiae?

Thrombocytopenia, platelet defects, mild factor deficiencies, or high blood pressure.

What are purpura?

Hemorrhages about 3 mm to 1 cm.

What can cause purpura?

Petechiae causes plus vasculitis or vessel fragility.

What is ecchymosis?

A bruise larger than 1 cm.

What is the size order of skin hemorrhages?

Petechiae, purpura, then ecchymosis.

What is the key difference between ecchymosis and hematoma?

Ecchymosis is flat discoloration; a hematoma is a palpable blood collection.

What is hemostasis?

The normal process that stops bleeding.

What happens in primary hemostasis?

Platelets form a platelet plug.

What happens in secondary hemostasis?

Fibrin stabilizes the platelet plug.

What is thrombosis in relation to hemostasis?

Abnormal activation of coagulation that blocks vessels.

What three components are essential for coagulation?

Blood vessels, platelets, and coagulation factors.

What happens to arteries immediately after injury?

They constrict.

What does vessel injury expose?

Extracellular matrix and tissue factor.

What do activated platelets do?

Release granules that recruit more platelets.

What stabilizes the platelet thrombus?

Fibrin.

What protein helps platelets adhere?

von Willebrand factor (vWF).

What factor is key in the prothrombinase complex?

Activated factor X (Xa).

What does prothrombin become?

Thrombin.

What does thrombin convert fibrinogen into?

Fibrin.

How many coagulation factors are numbered?

I through XIII, with no factor VI.

What are the two major coagulation pathways?

Tissue factor and contact activation pathways.

What is the role of the tissue factor pathway?

It triggers coagulation.

What is the goal of the tissue factor pathway?

Generate a thrombin burst.

What factor is tissue factor?

Factor III.

What test evaluates the tissue factor pathway?

PT.

What is PT commonly reported as for warfarin?

INR.

What drug is monitored with PT/INR?

Warfarin.

Which factors are vitamin K dependent?

II, VII, IX, and X.

What is the role of the contact activation pathway?

It sustains coagulation.

What can activate the contact activation pathway?

Thrombin or negatively charged surfaces.

What test evaluates the contact activation pathway?

aPTT.

What drug can be monitored with aPTT?

Heparin.

How does heparin work in this pathway?

It activates antithrombin III.

What factor is deficient in hemophilia A?

Factor VIII.

What factor is deficient in hemophilia B?

Factor IX.

What happens to aPTT in hemophilia?

It is prolonged.

What happens to PT in hemophilia?

It stays normal.

What happens to platelets in hemophilia?

They remain normal.

What happens to bleeding time in hemophilia?

It remains normal.

What are DOACs?

Direct-acting oral anticoagulants.

What does dabigatran target?

Thrombin.

What do rivaroxaban and apixaban target?

Factor Xa.

What is one advantage of DOACs?

They have more predictable effects.

Do DOACs usually need routine anticoagulation monitoring?

No.

What is a major concern with DOACs?

Bleeding risk.

What is a thrombus?

An intravascular blood clot.

What happens when a thrombus dislodges?

It can travel and become an embolus.

What is Virchow's triad?

Stasis, endothelial injury, and hypercoagulability.

How does stasis promote thrombosis?

It increases platelet contact with vessel walls.

What can cause endothelial injury?

Atherosclerosis, inflammation, and smoking/nicotine.

Where is endothelial injury especially important?

Arterial thrombosis.

What is hypercoagulability?

An increased tendency to form clots.

What are major thrombosis risk factors?

Immobility, age, smoking, atrial fibrillation, MI, surgery, fractures, burns, tumors, and prosthetic valves.

What are the main clinical thrombotic problems?

DVT, pulmonary embolism, and arterial thrombosis.

What are common DVT symptoms?

Swelling, pain, and redness.

What imaging test is used for DVT?

Ultrasound.

What blood test may support DVT diagnosis?

D-dimer.

What are D-dimers?

Fibrin breakdown products made when plasmin digests clots.

What does a negative D-dimer suggest?

Thrombosis is unlikely.

What is first-line DVT therapy?

DOACs or heparin.