Liu Xingting smiled, and finally achieved his goal, "Because the series of structural changes, such as the enlarged brain and smaller jaw, also made the human face flattened instead of protruding like other primates.
But in general, the human brain is still a bit too big. The problem of the large head directly affects the human childbirth process.
Because of bipedal walking, the human pelvis is somewhat narrow, and the birth canal is, on average, more than two centimeters smaller than the diameter of the baby's head. Although the baby's skull can shrink a little bit, it is still very reluctant.
This turns the birth into a miraculous acrobatic event, with the baby advancing through the birth canal and twisting ninety degrees to be born, while the mother sweats, screams and snarls for hours. exhausted.
Before human society entered modern times, no other animal on earth had a higher mortality rate during childbirth than humans.
Even until now, no other animal has suffered so much during childbirth.
For example, for our close relatives of primates, childbirth often only takes a few minutes, and the whole process is as smooth as turning on the tap to turn on the water.
And even with such a painful birth process, it takes many years for human infants to mature.
Some studies now confirm that although the human body matures in the teens, the brain does not fully mature until around the age of twenty-five.
Compared with animals that are born almost fully developed, humans are really different. This also has to be said to be a negative impact caused by changes in human body structure.
In short, evolution has given us a distinctive body structure, but it has also cost us a lot.
Back pain, herniated discs in the lumbar spine, painful childbirth and long growth periods are all problems unique to our anatomy. "
Liu Xingting's explanation was really based on medical observation. Everyone in the car nodded in praise, and even the medical staff gave a thumbs up.
Chu Lihua also has a deeper understanding of Liu Xingting, he is really outstanding in these aspects.
His understanding of life is so detailed, I believe the children will also
Chu Lihua shook her head in embarrassment. At this time, she actually started to think about this. It seems that his method of diverting attention is really effective.
Glancing at Xiao Qi, Chu Lihua silently lowered her head again, Xiao Qi, Xiao Qi
Fortunately, it was time to stop for meals and supplies, otherwise Chu Lihua would be even more embarrassed.
Although Chu Lihua wanted to accompany Xiao Qi in the car every time, Liu Xingting always pulled her out of the car on the grounds that she was not professional as a medical staff.
This period of time is the only time to get out of the car and walk around.
After the meal, I returned to the car to continue the previous topic.
In fact, this is also good, otherwise Chu Lihua's nerves are too tense.
¡ª¡ª"Before the meal, we finished talking about the differences in the structure of the human body. Next, let's look at the second aspect: what unsolved mysteries about our body, and what new discoveries have subverted our traditional cognition.
Each of us thinks that we know our body well, but we don't. Our ignorance of our bodies is sometimes incomprehensible even to ourselves.
Although we have been able to replace important organs such as the heart, we still don't know why people yawn, why people have fingerprints, and how the sense of smell works.
Even for such a common and excruciating pain as migraine, we often cannot find the cause. "
These are really easy to attract people to think about, indeed, Chu Lihua is really interested in this kind of problem.
The body is used for a lifetime, how can we do it if we don¡¯t understand it?
¡ª¡ª"The more we try to understand ourselves, the more questions we discover. For example, we have long known that there are taste receptors on the tongue, which are used to taste taste.
However, later we also found that there are taste receptors in the gut and throat, and apparently they are not used for taste.
More recently we've discovered that there are taste receptors in the heart, lungs, and even breasts, but no one knows what they're doing there.
But intriguingly, these strange taste receptors also send signals to the pancreas to regulate insulin output.
On some of the more important issues, we surprise ourselves with our ignorance. Although we all know that if we don't sleep for a long time, we will die, but we don't know what is the use of sleep. We can only say that it is probably a kind of maintenance and repair for the body.
We don't know how much sleep is best for health and well-being, why some people fall asleep easily and others suffer from insomnia, let alone dream.
We don't even know about our reproduction. We know that the average man ejaculates 75 million sperm per ejaculation, but we don't know why so many sperm are needed.
We also know the great reproductive potential of women. A fetus that is just 20 weeks old already has 6 million eggs in its body.
By the time she is born, that number will drop to a million. By the time a woman reaches reproductive age, there will be 180,000 ready eggs.
Why did she lose so many eggs along the way, yet enter reproductive age with far more eggs than needed? This also belongs to the unknown mystery of life.
We also don't know what triggers labor, we imagine that maybe there is something like a timer, and when the baby matures, it will send a signal to the body, telling the body that the baby is ready to be born.
But where this mechanism is and how it works, no one can say clearly. "
None of Liu Xingting's questions could explain why, but they all listened attentively.
Especially as to why he would give birth when the time came, even he, an obstetrician and gynecologist, didn't know, let alone Chu Lihua.
However, regarding this point, Chu Lihua really had an idea, "Could it be the brain prompted by some kind of hormone produced by the body?"
Liu Xingting shook his head, "There can only be an approximate time period for hormone levels, and the specifics are really unclear. Therefore, in fact, many children born by caesarean section have not reached the time yet. But it can only be an approximate time."
Seeing that other nurses were looking at him, Liu Xingting knew that there were some things that he could only say when he was alone with Chu Lihua.
He thought about it, and changed the topic, or another aspect. Anyway, he has a very thorough understanding of these things.
Seeing Chu Lihua look at Xiao Qi lovingly again, he actually felt very sad.
For Xiao Qi, ever since he knew his life experience, he also felt sympathetic. (Remember the site URL: www.hlnovel.com