I understand that aspirin prevents blood clots from forming by interfering with the clotting action. I want to know at which stage aspirin interferes with clot forming and what really happens in the process. I've used google to understand this but did not find a satisfactory answer.
For example, here I found:
How can aspirin prevent a heart attack? Aspirin interferes with your blood's clotting action. When you bleed, your blood's clotting cells, called platelets, build up at the site of your wound. The platelets help form a plug that seals the opening in your blood vessel to stop bleeding.
But this clotting can also happen within the vessels that supply your heart with blood. If your blood vessels are already narrowed from atherosclerosis — the buildup of fatty deposits in your arteries — a fatty deposit in your vessel lining can burst.
Then, a blood clot can quickly form and block the artery. This prevents blood flow to the heart and causes a heart attack. Aspirin therapy reduces the clumping action of platelets — possibly preventing a heart attack.
Every site I visited had descriptions like this (mostly concentrated on the medicinal side). I want to know what aspirin does that prevents blood clotting at the chemical level, which I haven't been able to find.