Pathology 9

• Blood circulation delivers oxygen and nutrients and removes wastes.
• Normal blood circulation results in little net movement of water and electrolytes into the tissues.
• Piping system includes lungs, heart, and organs.
• A blocked pipe in the piping system can lead to thrombosis, embolism, oedema, effusion, and haemorrhage.
• Pathological conditions can include hyperaemia and congestion, oedema and effusion, trauma of the blood vessel, loss of structural integrity, and haemostasis, which is physiological blood clotting that prevents excessive bleeding after blood-vessel damage.
• Inadequate haemostasis can lead to haemorrhage, while inappropriate haemostasis can lead to inappropriate clotting (thrombosis).
• Embolism and infarction are other potential pathological conditions.
• Shock can be a result of any of these pathological conditions.
• Right common carotid artery occlusion is measured at A1.
• Terminal arteriole occlusion is represented by B.
• Left common carotid artery occlusion is measured at P1.
• Collateral arteries develop functional inter-arteriolar anastomoses with minimal functional flow during the development of atherosclerosis.
• Coronary artery circulation occurs without inter-arterial anastomoses in the presence of atherosclerosis.
• Posterior ciliary artery occlusion, with no arteriolar anastomosis, is represented by C.
• Parallel Circulation & End ArterioleTraupe's "Assessment of the human coronary collateral circulation" is published in Circulation 2010.
• Coronary artery circulation occurs with inter-arterial anastomoses between the right coronary artery and the occluded left anterior descending artery in the presence of atherosclerosis.
• Thrombo-embolism is a condition where a thrombus dislodges and travels to another part of the body.
• Both artery and venous thrombi extend towards heart.
• Thrombi in smaller arteries may not show lines of Zahn.
• Depends on the involved site, it can be venous, arterial, mural (cardiac chamber/ aorta), or vegetation (cardiac valve).
• Thrombi come to clinical attention when they obstruct arteries/veins, or give rise to emboli.
• Virchow’s Triad consists of three factors: Endothelial injury, Turbulence flow, and Hypercoagulability.
• Extracted branched thrombus indicates origin from venous bifurcation in the legs.
• Thrombi vary in size and shape depending on the involved vessel and the underlying cause.
• Lines of Zahn are grossly and microscopically apparent laminations in the thrombus, indicating that it formed in flowing blood.
• Deep vein thrombosis is a condition where a blood clot forms in a deep vein, usually in the legs.
• Aneurysm are abnormalities in the flow of blood through the arteries.
• Venous thrombus leads to pulmonary embolism at the junction of the pulmonary trunk.
• Thrombi are focally attached to the vascular surface at the point of initiation.
• Acute Myocardial Infarction is a condition where the heart muscle dies due to lack of oxygen.
• Occlusive venous thrombi have lines of Zahn.
• Hypercoagulability/Thrombophilia is a condition where the blood has a tendency to clot, often leading to venous thrombosis.
• Infarction is complicated by thrombosis/ embolism, vasospasm, vascular rupture, torsion, and intraluminal/ extravascular aetiology.
• Fetal tissue can be obtained from squamous cells, lanugo hair, fat from vernix caseosa, and mucin.
• Pregnancy can lead to air embolism due to changes in the vascular system.
• Intravascular air embolism is a type of vascular air embolism that occurs when a gas enters the bloodstream through a negative pressure gradient.
• Factors that influence the development of an infarct include severity, anatomy of the vascular supply, rate of occlusion, tissue vulnerability to hypoxia, and others.
• Air embolism can occur due to a variety of factors, including intravascular procedures, endovascular/ interventional procedures, and communication between the vasculature and outside air.
• Air embolism is a condition where a gaseous mass enters the bloodstream through a decompression or mechanical ventilation.
• Types of vascular air embolism include decompression sickness, mechanical ventilation (barotrauma), endovascular/ interventional procedures, and communication between the vasculature and outside air.