The heart pumps huge amounts of blood
Your heart is an amazingly hardworking organ. In five minutes, it drives five liters of blood through the circulatory system, and in an hour - 300 liters, while making 4200 strokes. It pumps over 2.5 million liters of blood every year to fill the Olympic pool. To do this, the heart has to make 38.5 million contractions every year.
Scientists have figured out how to do without blood
What happens when the heart stops? From time immemorial, cardiac arrest has been identified with the death of a person. However, scientists have developed a method to save people whose hearts have stopped working - by putting them into suspended animation. This new technology assumes no brain or heart activity in humans and involves replacing the patient's blood with saline.
This technique blurs the line between life and death. During its implementation, the patient's body is cooled to 10-15 ° C. Since metabolism stops at this temperature, the role of blood as an oxygen carrier to cells is lost. As a result, the blood can be replaced with a salt water solution.
We still don't know why blood is divided into groups
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For a hundred years now, one of the most important mysteries of our circulatory system has remained unresolved. We never found out why we have different blood types. However, the fact that the groups do exist is beyond doubt - the groups are set by special molecules on the surface of blood cells.
Using these molecules, enzymes recognize red blood cells. Therefore, when transfusing blood, it is so important to consider group compatibility. If this requirement is not met, new blood will be rejected by the body.
However, why is blood divided into types? Wouldn't it be easier to have one universal group? Nobody knows the answers to these questions.
Synthetic and pork hearts
Xenotransplantation (tissue transplantation from animals to humans) dates back to 1682, when Dutch surgeon Job Janszoon van Meekeren reported how he managed to "repair" a Russian soldier's skull using a piece of dog bone. Today, researchers are learning to transplant pig hearts into humans. No less intensive research is being conducted in the field of tissue engineering, which is designed to find ways to grow hearts from scratch outside the human body.
Consuming human blood as medicine
Enthusiasts argue that human blood is the best treatment for a variety of conditions, from headaches to gastritis. Adherents of this approach, who call themselves sanguinaria, recommend drinking as fresh blood as possible.
Official medicine does not recognize any medicinal properties of human blood. Sanguinaria seem to do better as a result of the placebo effect.
Based on materials from BBC-future
ALEX KUDRIN