Red Blood Cell Tour (science fiction story)

It is said that SARS is popular on the earth, and people are afraid to travel. I don't care that much. I have to travel. Why? I'd better introduce myself. My name is red blood cell, because I have red iron hemoglobin in my body, so it is red. My home is red bone marrow, where there have been many companions, walking around the human body with plasma. My average life expectancy is 120 days. In this short 120 days, I will try my best to complete my duties, send the necessary oxygen to all parts of my body, and at the same time take away a part of carbon dioxide in all cells, so that cells can carry out normal physiological activities.

On this day, I was pushed into my right atrium by a powerful force, and I wanted to break away from this thrust and run back. However, that door is very strange, only allowed to enter, not allowed to return. I quickly asked the partners around me what was going on. He replied, "little brother, that's called an atrioventricular valve, which can only be opened in one direction." When we enter the right ventricle, we can only move forward. There is also a door in front, called the arterial valve, which acts like an atrioventricular valve, preventing us from running back, passing through the arterial valve, passing through the pulmonary artery, and then entering the lungs. " Before he finished speaking, as soon as the right ventricle contracted, we were pressed into the pulmonary artery. I held my companion's hand tightly. ...

Suddenly, the front appeared, and I quickly asked, "Which way shall we go?" He said, "Either side will do. They are all branches of the pulmonary artery. " . After entering a fork in the road, the pipeline narrowed obviously and our speed slowed down. In the end, the pipeline can only let us pass one by one. Although it is so narrow, I feel very comfortable, because these pipes, as thin as hair and with extremely thin walls, are tightly wrapped in small bubbles, which are filled with fresh air. At this time, the hemoglobin in my body began to play its unique role, and I took oxygen to my heart's content. After inhaling, I found myself looking much better. The originally dark red body turned into bright red. I am very happy to hold my companion's hand and move on.

This time, the road is getting wider and wider. My partner told me that we are taking the pulmonary vein and will soon enter the left atrium. At this moment, we suddenly poured into the left atrium and entered the left ventricle through the atrioventricular valve. The left ventricle is similar to the right ventricle, but thicker than the right ventricle. Here, I suffered more pressure than the right ventricle and poured into the arteries of the whole body. My partner told me, "after entering the systemic artery, we will walk a long way, so we must have enough pressure to reach our destination." The systemic artery is spacious, even if the pressure of the left ventricle is so great, it doesn't matter to it, because its wall is much thicker than the vein. After a long walk, we reached the capillary network of our feet. There, I release the oxygen in my body to those cells that need it badly. And all kinds of waste and carbon dioxide in the cells are pouring into the plasma. I feel suffocated and my body turns dark red again. I walked into the inferior vena cava in a daze, but I always felt that there was no pressure behind me. I really want to go back, but there are many things like pockets on the road, which stopped me and forced me to move forward. I thought: that must be called a venous valve.

Finally, I finally listlessly stepped into my right atrium. I quickly cheered up and rushed forward to breathe the fresh air in my lungs.

Due to the deterioration of the earth's environment, my number will decrease among some people, which is the so-called off-season of tourism. With the development of science and technology, you can look for me from stem cells in other people's bone marrow, and I will continue to travel in other countries.