In the carotid sinus and the aortic arch

changes in arterial pressure

The right coronary artery takes its blood supply from the right coronary sinus, just above the aortic valve and sprouting from the ascending aorta. The left coronary artery takes its blood supply from the left coronoray sinus, also coming off of the ascending aorta. From these main coronary arteries, the rest of the branch coronary arteries are derived.

True

Aortic dilation is the widening of the aorta. This widening could be an aortic aneurysm.