Circulation And Tissue Perfusion And Cardiac And Vascular Health Flashcards
What is the structure of the Heart?
- 4 chambers: 2 atria, 2 ventricles
- 4 valves
- Coronary arteries
What is the function of the heart?
- pulmonary (right) circulation
- systemic (left) circulation
What is Pulmonary Circulation?
- right ventricle pumping venous blood to the lungs to get oxygenated
- low pressure
What is Systemic Circulation?
- left ventricle pumping oxygenated blood out to organs of the body
- high pressure
Why is the Left Ventricles wall much thicker in comparison to the right?
Because it is required to pump blood throughout the body under higher pressure
What are the two functions of the Circulatory System?
- blood vascular system
- lymphatic system
What is the Blood Vascular System?
Composed of muscular pump (heart) connected to vessels that either deliver blood to organs and tissues (via arteries) or returns blood to the heart (via veins) to complete the circuit
What is the Lymphatic System?
a passive drainage system for returning excess extravascular fluid to the blood vascular system
How can normal fluid balance be disturbed?
by pathologic conditions that alter:
- endothelial function
- increase vascular hydrostatic pressure
- decrease plasma protein content
What is the result of altered fluid balance? (Overhydration)
accumulation of fluid in tissues due to net movement of water into extravascular spaces - edema
What is Hemostasis?
the process of blood clotting that prevents excessive bleeding after blood-vessel damage
What does inadequate Hemostasis result in? (4)
- hemorrhage
- hypotension
- shock
- possibly death
What can Thrombosis or Embolism cause?
Obstruction of blood vessels, potentially causing ischemic cell death
What does derangements in fluid balance or blood supply cause? (6)
- edema
- thrombosis
- embolism
- ischemia
- infarction
- altered perfusion
What is Ischemia?
inadequate blood supply to an area of tissue
What are the causes of Ischemia? (2)
- decreased blood supply: inadequate cardiac output
- obstruction of blood vessels
What is Infarction?
Tissue death if ischemia is severe and complete
- results in coagulative necrosis
What are the types of Infarcts?
- white
- red
What is White Infarct?
- pale infarct
- in organs with single blood supply: heart, kidney, spleen
- Arterial occlusion/insufficiency
What is Red Infarct?
- hemorrhagic infarct
- in organs with dual (collateral) blood supply: liver, lung, intestine
- Venous occlusion/insufficiency
What can be done to treat plaque build up?
- medications
- angioplasty
- Bypass surgery
What is Coronary Artery Bypass Surgery?
When a vein is grafted to the diseased coronary artery to provide a “bypass” or “detour” around the narrowed segment
What is PCI?
Percutaneous Coronary Intervention
What is Acute Coronary Thrombosis?
- when the build up of plaque in the coronary arteries rupture, causing occlusion (blockage of the blood supply)
- causes acute myocardial infraction
What is Acute Myocardial Infraction?
when a narrowed coronary artery becomes acutely occluded by a thrombus which usually forms in the lumen overlying a chronic plaque
What is the treatment for Acute Coronary Thrombosis?
timely administration of thrombolytic drugs can “dissolve” the thrombus and restore blood flow, preventing or limiting infarction
What is a Thrombosis?
formation of a mass (clotted blood - an aggregation of coagulated blood) within the heart or blood vessels; adherent to the vascular endothelium
What does a Thrombus consist of? (4)
- platelets
- Fibrin
- red blood cells
- white blood cells
What are the causes of Thrombosis?
- Endothelial Injury
- Stasis or turbulent blood flow
- hypercoagulability of the blood
What are the causes of Endothelial Injury?
- physical injury
- inflammation
- endothelial activation/alteration
What are the causes of changes of blood flow?
- turbulence
- stasis (slow circulation): lack of activity, decreased cardiac output, increased blood viscosity
What are the causes of changes in blood composition?
- increase in platelets
- hypercoagulability
What is Hypercoagulability?
abnormally high tendency of blood to clot
What causes Hypercoagulability?
- genetic abnormalities
- acquired conditions (prolonged bed rest)
What is the outcome for Thrombosis? (4)
- can dissolve or be lyzed by fibrinolytic activity
- can increase in size and obstruct vessels
- can breakdown and form emboli
- can become organized and may recanalize