Question

ENGG311 Cardiovascular Engineering Atherosclerosis is the build-up of plaque on the inner wall of the arterial network. With the aid of sketches, identify 2 locations that are prone to atherogenesis and refer to the fluid dynamics that contributes to the build-up of plaque deposits in these regions. [20 marks)

Answer 1

Atherogenesis is the process of formation of plaques in the innermost layer of arteries i.e., Tunica intima.Atherogenesis leads to atherosclerosis which is developed due to the accumulation of lipids and inflammation which varies significantly in different individuals. Atherogenesis can be observed in these 2 location i.e., carotid arteries and the coronary arteries.

Thrembus formation Lipid Monogyntes Platelets Tof fcam D > foam SCOR VE . Formation A Intima scell * Inflammation : collagen A Migration & Media a n ysmeeth muscle layer Adventina

In the first stage,Early atherosclerosis:- Low density lipoproteins (LDL) gets accumulated and inflammation of arterial wals occur. The lipids play a key role in the development of atherosclerotic plaques.

Lesion progression:- The smooth muscle cells and macrophages die by apoptosis (programmed cell death ).These dead cells derive extracellular lipid which develops into plaques.Plaques limit the blood flow and causes abnormal narrowing in blood vessels i.e., stenosis.

Thrombosis:- Due to the rupture of the fibrous cap of plaques the blood coagulation components come in contact with the plaque which produces thrombi.