The illustration contains two sections:

1. On the top left, a diagram showing an artery narrowed by plaque buildup.
2. A small segment of artery in heart is enlarged to explain how blocks are formed in artery. This process is explained in a sequence.
   1. A picture showing plaque buildup in the wall. The direction of blood flow is indicated by a downward arrow. The picture is captioned ‘Plaque builds up in wall’.
   2. A picture showing the rupture of the cap on the plaque. The direction of blood flow is indicated by a downward arrow. The picture is captioned ‘Cap ruptures’.
   3. A picture showing blood clot formation in the ruptured plaque which interrupts the blood flow. The obstruction to the blood flow is indicated by a curved arrow. The picture is captioned ‘Blood clot forms and blocks the artery. Or, the clot dislodges and blocks a smaller artery’.