Blood Vessels, thrombosis, etc Flashcards
Elastic arteries
Multiple elastic layers (laminae) in media
Aorta, arch vessels, brachial, iliacs, pulmonary trunk, main and lobar arteries
Conduits, deliver large volumes
Muscular arteries
2 elastic laminae ( IEL and EEL) inside and outside muscular media
Contribute to vascular tone and vasoconstrict
Arterioles
Greatest effects on peripheral vascular resistance. SM cells, endothelial cells, no elastic layer
Greatest number compared to other types
Adventitia
Layer with abundant elastic tissue in veins
Arterial intima
Consists of basement membrane, ground substance, and endothelial cells within IEL
Accumulation of smooth muscle cells and fibroblasts a non-specific response to injury
Hypertensive vascular disease
Most susceptible are small vessels - renal, retinal, cerebral arteries
Arterionephrosclerosis
Hypertensive renovascular disease. Hyaline arteriolar sclerosis (fibrosis, scarring) or hyperplastic arteriolosclerosis- Concentric thickening with elastosis of muscular arteries (onion-skinning)
Associated with malignant HTN, may cause ischemic damage
Arteriosclerosis
Any type of arterial thickening. Ex renovascular changes, medical calcification
Atherosclerosis
Intimal disease of elastic and muscular arteries- intimal thickening with addition of LIPID material (atheroma)
Aorta, iliacs, carotid, coronary arteries most susceptible
Endothelial damage initiating event
Atheroma
During atherosclerosis, activated ECs allow adhesion and migration of macrophages and lymphocytes, LDL enters, mac and lymph stimulate proliferation of SMCs, apoptotic cell death allows for accumulation of cell debris with leads to
Atherogenesis
Angiogenesis in growing atheroma, leaking red cells and fibrin into core, endo damage results in small luminal thrombi, large thrombi result in rupture of fibrous cap, or erosin of large areas of denuded endo
Acute syndromes generally based on sudden narrowing by thrombus
Media
The wall of a true aneurysm is composed of
Congenital aneurysms
Cerebral (berry), Marfan syndrome, Ehlers Danlos syndrome type IV, fibromuscular dysplasia associated with
Dissecting aneurysms
Usual site is ascending/thoracic aorta. Predisposing factors are HTN, Marfan’s, bicuspid aortic valve.
AAA
most common spot is between renal and iliac arteries
IVC thrombosis
Usually caused by tumors (RCC, hepatocellular carincoma, testicular germ cell tumors) infiltrating the lumen
Budd-Chiari Syndrome
Thrombosis of hepatic vein, resulting occlusion of mesenteric and hepatic circulation
Leads to liver failure, massive ascites, hepatosplenomegaly
Cause: idiopathic, tumor (HCC), thrombotic states
Portal vein thrombosis
Thrombosis in venous supply to liver. Caused by infections (pylephlebitis, appendicitis, diverticulitis, umbilical cord infections)
Frequent in cirrhosis
Results in PORTAL HTN
Edema
increased EC fluid (transudate- water, electrolytes). Collects in interstitium and serosal cavities
Causes are increased hydrostatic pressure, decreased plasma osmotic pressure
Exudate
edema from inflammation or damage where blood cells also leak out ??
Effusion
Edema from serosal cavity
Ascites
Edema fluid in peritoneal cavity- hepatic circulation
Increased hydrostatic P due to scarring (central vein obstruction)
Intrinsic liver disease OR right heart failure (liver goes to R heart)
May have osmotic component because of hypoproteinemia
Splenomegaly
Anasarca
Edema all through body
Dependent edema
Edema in systemic circulation. Heart failure is MOST COMMON CAUSE. For children, protein losing conditions (ex nephrotic syndrome) are also a cause
Pulmonary edema
Due to heart failure (acute and chronic, increases hydrostatic pressure), infections (aspiration, bacterial pneumonia) , toxins (kidney disease, cocaine, smoke) , non-inflammation endothelial damage (HAPE)
Heart failure
Most common cause of pulmonary edema
Albumin
Made in the liver, so when liver fails, hypoproteinemia
Decreased osmotic pressures
Nephrotic syndrome, cirrhosis, protein-losing enteropathy, malnutrition, and shock will give generalized edema because of
Vascular congestion
Increased fluid (blood) WITHIN vascular channels, usually associated with edema and most common are pulmonary and liver
Hemosiderin macrophage
“Heart failure cells”. Sign of chronic heart failure. Increased capillary pressures and small hemorrhages result from pulm congestion and you see these cells
red/brown cells
Chronic right heart failure (hepatic into IVC)
Chronic liver congestion (Nutmeg liver) is caused by
Pressure backup causes necrosis
Splenic congestion
Obstruction at level of portal vein leads to congestion where?
Centrolobular liver congestion
Obstruction at the level of the right heart or central vein causes congestion where?
Pulm congestion with hemosiderin macrophages
Obstruction at level of pulm veins/left heart causes
Hematoma
Clot outside a vessel
Endothelial injury, hypercoagulability, abnormal blood flow (stasis)
Virchow’s triad of prothombotic factors
Systemic embolism
Embolism usually from cardiac source (valves, ventricles) or iatrogenic (therapeutic tumor embolization)
Pulmonary embolism
Source of embolism usually in leg veins. Most common embolus the causes symptoms
Paradoxical embolism
Embolism with venous source that ends up in brain. Crosses oval foramen to reach systemic circulation
Shock
Systemic hypotension resulting in tissue hypoperfusion and hypoxia
