The most important thing about the Pixel, for Google and Android and probably you as well, is that this is the first phone to have the Google Assistant built in. Google Now is dead, long live the Google Assistant. Itâs a core piece of the phone, available everywhere just the way Siri is on the iPhone.
1 Understanding the role of each of the four heart valves can help you learn why you might need to be on the look out for certain signs and symptoms. 2  Additional valve terms and related conditions can help you broaden your understanding, too.
The heart has four valves â the aortic, mitral, tricuspid and pulmonary valves. Like valves used in house plumbing, the heart valves open to allow fluid (blood) to be pumped forward, and they close to prevent fluid from flowing backward. Human heart valves are flaps of tissue called leaflets or cusps. Heart valve problems fall into two major categories: Stenosis â The opening of the valve is too narrow, and this interferes with the forward flow of blood. Regurgitation â The valve doesn't close properly.