septum
These one-way 'doorways' are called valves. They exist in places such as the heart and the oesophagus/stomach opening.
The heart is a one-way pump. By maintaining a pattern of certain chambers opening and closing, constricting and relaxing, the blood is pumped one way and one way only. There are also hundreds of one-way valves throughout the arterial system that keep backflow from occurring.
When they are working properly, the four valves of the heart ensure one-way blood flow. The atrioventricular valves prevent backflow into the atria, and the semilunar valves prevent backflow into the ventricles.
Heart valves prevent blood from flowing backwards.
Another way to say "heaert to heart" is to say "one to one" it could mean that ,you belong with them or anything to say in commen or somthing charming
aorta
every one is awesome in a special way
if i got this right snakes are the only one opening animals and have to puke their food after digestion while two opening animals like us just get rid of the waste the way we do.
The opening ceremony of the Winter Olympics is special because it's the beginning of the Winter Olympics. They're introducing all of the athletes that have came all the way there to try their best to win the gold medal.
This infection causes swelling and muscle damage to the heart. It can also damage the heart valves in a way that keeps the blood from moving through the heart normally. The infection can cause heart valve leaflets to stick together, which narrows the valve opening. Also, the infection can scar the valves.
One way a doctor treats heart disease is to do a heart transplant. That is, removing the heart of the patient, and replacing it with a healthy heart of someone who has died.
In the heart as a biological example? In one way sewedge systems?