What does sira kathinya refer to in pathological terms?

• A. Thickening of blood vessels (atherosclerosis)
• B. Narrowing of blood vessels
• C. Dilation of arteries
• D. Inflammation of arteries due to infection

Answer: (A)

The concept being tested is the description of atherosclerotic change in arteries. Sira kathinya refers to thickening of the arterial wall due to atherosclerosis, where lipid-laden plaques accumulate in the intima, inflammatory cells participate, and smooth muscle cells migrate and lay down matrix. This combination causes the wall to become thicker and stiffer and the lumen to narrow over time, which impairs blood flow and can lead to ischemia in tissues supplied by the affected vessels.

Why this fits best: thickening of the vessel wall from plaque buildup is the defining feature of atherosclerosis, whereas dilation would imply an enlargement (not typical of atherosclerotic plaques), and inflammatory changes due to infection describe vasculitis rather than the chronic lipid-driven plaque formation. Narrowing is a consequence of the thickening, but the term in question specifically denotes the structural thickening itself.