动物实验 z-bo 2020-09-01 441

　　The latest research by researchers shows that it takes 20 seconds for animals to urinate more than 20 kilograms. Elephants and cats are the best time to urinate, which can effectively avoid attacks by predators. Georgia Institute of Technology conducted a survey of 32 animals and found that the volume of elephant bladder is 3,600 times that of cat bladder (elephant bladder 18 liters, cat bladder 5 ml), but each animal has proved that the urination time is the same. In fact, this work is very useful and can tell engineers how natural organisms use gravity to regulate the flow of liquids. according to

　　According to the research team, in fact, all animals weighing more than 3 kg have the same time to urinate. Associate Professor of Georgia Institute of Technology, David Hugh (David Hugh) said: "This may be due to the long urethra of large animals. The weight of the fluid in the urethra causes the fluid to move. At the same time, the urethra is very long, which increases the flow rate. The urethra is bigger. The length is 1 meter."

　　The pressure of urethral fluid is equal to the pressure of a pool of 1 meter deep. The flow rate of elephant urine is 4 meters per second, which is equivalent to the amount of water released by five shower heads per second. David explained that if the elephant's urethra is short, it will take longer to urinate and will be vulnerable to sudden attacks by predators. This study shows that the flow of urine is controlled by bladder pressure generated by muscle contraction. The study has now been published in the proceedings of the National Academy of Sciences recently published. David and graduate student Patricia Young discovered that gravity quickly expels urine from the bladder of large animals, and that gravity has little effect on small animals.

　　Patricia: "Small animal urine is a droplet because it is very sticky and has a capillary effect like urination in space. Rats urinate in less than 2 seconds, and bats in less than 1 second."

　　Researchers observed the urination process of 16 animals in the zoo and watched the urination video of 28 animals on YouTube. The observed animals are elephants, cows, horses, dogs, cats, etc. The more they observe, the more they realize that this discovery is particularly important in engineering. We see that we can solve the problem. Natural organisms use gravity to solve problems. This is not a waste of animal energy, but a problem. "