Saturday, March 21, 2009

-ULCER-




describe ulcer kat atas tu.... (yg xtahu nak describe leh rujuk buku PE ORTHO page 13..) ulcer yg belah kiri tu disebabkan venous problem... yg belah kanan tu sebab DM...nnt post kat komen cmne ulcer ulcer nie leh jadi...

"BERUSAHA KEARAH KEJAYAAN BERSAMA"

1 comments:

hulala gurl on March 23, 2009 at 12:55 AM said...

The exact etiology of venous ulcers is not certain, but they are thought to arise when venous valves that exist to prevent backflow of blood do not function properly, causing the pressure in veins to increase.[2][3][4][5] The body needs the pressure gradient between arteries and veins in order for the heart to pump blood forward through arteries and into veins. When venous hypertension exists, arteries no longer have significantly higher pressure than veins, blood is not pumped as effectively into or out of the area,[2][3][4][5] and it pools.

Venous hypertension may also stretch veins and allow blood proteins to leak into the extravascular space, isolating extracellular matrix (ECM) molecules and growth factors, preventing them from helping to heal the wound.[2][5] Leakage of fibrinogen from veins as well as deficiencies in fibrinolysis may also cause fibrin to build up around the vessels, preventing oxygen and nutrients from reaching cells.[2] Venous insufficiency may also cause white blood cells (leukocytes) to accumulate in small blood vessels, releasing inflammatory factors and reactive oxygen species (ROS, free radicals) and further contributing to chronic wound formation.[2][5] Buildup of white blood cells in small blood vessels may also plug the vessels, further contributing to ischemia.[6] This blockage of blood vessels by leukocytes may be responsible for the "no reflow phenomenon," in which ischemic tissue is never fully reperfused.[6] Allowing blood to flow back into the limb, for example by elevating it, is necessary but also contributes to reperfusion injury.[3] Other comorbidities may also be the root cause of venous ulcers.[4]

It is in the crus that the classic venous stasis ulcer occurs. Venous stasis results from damage to the vein valvular system in the lower extremity and in extreme cases allows the pressure in the veins to be higher than the pressure in the arteries. This pressure results in transudation of inflammatory mediators into the subcutaneous tissues of the lower extremity and subsequent breakdown of the tissue including the skin.

 

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