Haemodynamic disorders Flashcards
What does fluid homeostasis require? 3
- Vessel wall integrity
- Osmolarity (solutes in plasma e.g. ions, proteins, urea, sugars)
- Maintenance of intravascular pressure (blood volume, smooth muscle tone)
What is haemodynamics?
The flow of blood through the circulatory system.
What factors are required for fluid homeostasis?
Vessel wall integrity, osmolarity, and maintenance of intravascular pressure.
What is edema?
Abnormally increased fluid in the interstitial tissue space.
What causes edema? 6
- Increased vascular volume/pressure
- decreased plasma protein content
- endothelial dysfunction
- lymphatic obstruction
- sodium retention
- inflammation.
What is hydrostatic pressure?
Pressure exerted by fluid that drives fluid from blood vessels into tissues.
What is colloid osmotic pressure?
Pressure that pulls water back into blood vessels due to the higher concentration of proteins like albumin.
What is the cause of pulmonary edema?
Increased hydrostatic pressure in the lungs, leading to fluid buildup.
What is hyperaemia?
Adaptive increase in blood volume in tissues due to environmental changes.
What causes vascular congestion?
Impaired venous return, leading to increased venous pressure.
What is thrombosis?
Formation of a blood clot within a vessel, often caused by endothelial injury, abnormal blood flow, or hypercoagulability.
What is the main cause of arterial thrombosis?
High shear flow and platelet-rich formation, often around ruptured atherosclerotic plaques.
What is atherosclerosis? Caused by what? 2
Chronic inflammatory disease of the arterial wall caused by fatty lesions and lipid buildup.
What are the types of shock? 6
Cardiogenic, hypovolemic, obstructive, neurogenic, septic, and anaphylactic shock.
What is septic shock?
Shock caused by a systemic infection, often bacterial, leading to vasodilation and reduced blood pressure.
What is the clinical significance of hemorrhage?
Loss of blood can lead to hypovolemic shock or iron deficiency if recurrent.
What is petechiae?
Minute hemorrhages (1-2mm) in the skin or mucosa due to thrombocytopenia or increased capillary pressure.
What causes purpura?
Small hemorrhages (3-10mm) due to trauma or vasculitis.
What is the cause of ecchymosis (bruising)? 3
Subcutaneous hemorrhage caused by trauma, platelet or clotting factor deficiencies.
What is a mural thrombus?
A thrombus that forms along the wall of a blood vessel without fully occluding it.
What is an occlusive thrombus?
A thrombus that fully occludes a blood vessel, preventing blood flow.
What is the difference between arterial and venous thrombosis?
Arterial thrombosis forms in high shear flow and is platelet-rich; venous thrombosis forms in low shear flow and is fibrin and erythrocyte-rich.
What is an atheroma?
A fatty plaque that forms in the arterial wall during atherosclerosis, consisting of lipids, foam cells, and inflammatory cells.
What happens during the plaque rupture stage of atherosclerosis?
The fibrous cap of the plaque breaks, exposing thrombogenic material, leading to thrombosis (atherothrombosis).
What is the first visible sign of atherosclerosis?
Fatty streak
Which type of lipoprotein gets trapped in the sub-endothelial space during the initiation of atheroma formation?
Low-density lipoprotein (LDL)
Which cells transform into foam cells during atheroma formation?
Macrophages
What is the main characteristic of plaque progression in atherosclerosis?
Formation of a fibrous cap
Which event is most likely to trigger atherothrombosis?
Plaque rupture
Which of the following is the first stage in the development of an atheroma?
Fatty streak formation
What are common complications of atherosclerosis? 5
Heart attack, stroke, peripheral artery disease, chronic kidney disease, and aneurysm.
What is the primary cause of pulmonary embolism?
Deep vein thrombosis (DVT) in the legs.
What is ischemia?
Insufficient blood supply to tissues, leading to a lack of oxygen and nutrients.
What is hypoxia?
A deficiency of oxygen in tissues, typically caused by ischemia.
What is the difference between a true aneurysm and a false aneurysm?
A true aneurysm involves all three layers of the vessel wall; a false aneurysm is a contained hematoma formed outside the vessel wall.
What is a fusiform aneurysm?
An aneurysm where the blood vessel bulges evenly on all sides.
What is a saccular aneurysm?
An aneurysm where the blood vessel bulges on one side.
What are the common causes of cardiogenic shock? 3
Myocardial damage (e.g., heart attack), arrhythmias, or pulmonary embolism.
What is hypovolemic shock?
Shock caused by loss of blood or plasma, such as from hemorrhage or severe burns.
What is obstructive shock?
Shock caused by an obstruction to blood flow, such as in a massive pulmonary embolism.
What causes neurogenic shock?
Severe damage to the central nervous system, causing loss of vasoconstriction and pooling of blood.
What is the cause of septic shock?
A systemic infection, often bacterial, that leads to widespread vasodilation and hypotension.
What is anaphylactic shock?
Severe allergic reaction that causes widespread vasodilation and decreased blood pressure due to the release of inflammatory mediators.
What is the pathophysiology of septic shock? cause what 3 things?
Bacterial components activate the immune system, causing widespread vasodilation, vascular leakage, and coagulation abnormalities.
What is the mortality rate for septic shock?
40-55%, depending on the severity of the shock.
Which bacterial component is responsible for activating macrophages and neutrophils in septic shock?
Lipopolysaccharide (LPS)
Which cytokines are primarily released during septic shock?
Interleukin-1 (IL-1) and Tumor Necrosis Factor-alpha (TNFα)
What is the effect of endothelial cell activation in septic shock?
Systemic vasodilation and hypotension
Which of the following is a major consequence of septic shock?
Increased blood clotting and thrombosis
Which of the following complications is associated with severe septic shock?
Multi-organ dysfunction syndrome (MODS)
what does a ruptured plaque cause? 3
- Acute narrowing of the vessel lumen
- Chronic occlusion (due to the growing plaque)
- Embolism (of ruptured plaque)
