With powder coating, the bottom line is that the aluminum is covered with a coating which cannot be repaired should any peeling or blistering occur. Polished stainless steel differs from powder coating primarily in that the base material is not covered with a coating and the materials are substantially different.
The baroreceptor reflex or baroreflex is the body's way of responding to a change in blood pressure. Baroreceptors in the arteries notice that something has changed. When they sense a change in pressure, they send out signals through nerves to a part of the brain called the brainstem.
In the case of baroreceptors in arteries, it's thought that on the baroreceptor nerve endings you can find channels for sodium and calcium. When there is a change in the pressure stretching the wall of the blood vessel, these channels open, allowing sodium and calcium to flood into the cell.