Can normal menstruation ovulate?
Although the menstrual cycle is normal, there may not be normal ovulation. Whether ovulation is normal or not, it is suggested to use B-ultrasound to detect a cycle to see if mature follicles can excrete follicular development. Anovulatory menstruation means that the ovary only secretes estrogen, but not progesterone, so the endometrium only changes during the proliferative phase. When estrogen reaches a certain level and the thickness of endometrium exceeds 10mm, a breakthrough endometrial exfoliation will occur. Female vaginal bleeding will be the same as menstruation, but it will not ovulate, which means menstruation will still come and it will not ovulate!
Usually, the menstrual cycle is 27-40 days and lasts for 3-7 days. If menstruation is not on time, it may mean that there are some problems in the body. The period from the day when menstruation is clean to the day before ovulation is the safe period before ovulation. The safe period after ovulation is from the first day after ovulation to the day before the next menstrual cramp. The safe period after ovulation is safer than that before ovulation. Women ovulate a few days after their menstruation is clean, and it is good for them to master certain calculation methods. Pregnant sisters should try to share the same room during ovulation, so there is a great possibility of pregnancy, while sisters who need contraception should avoid sharing the same room during ovulation.
Ovulation day is usually about 14 days before the next menstrual period, and ovulation period is 5 days before and 4 days after ovulation day, of which *** 10 days. If the menstrual cycle is irregular, sometimes it is only 23 days, sometimes it is as long as 35 days. Then the first day of ovulation is 23-8=5 and the last day of ovulation is 35- 1 1=24. In this case, the ovulation period may be as long as 24-5= 19 days. But this only shows that ovulation is possible during this period, and it is impossible to accurately calculate the date of ovulation.
How do eggs combine with sperm?
In many social units of social primates, only one male can reproduce. Because of the lack of direct competition, his testicles are often smaller. Humans are very similar to these primates. Human testicles are only the size of walnuts, which is one third of that of chimpanzees, and the proportion of abnormal sperm in human semen is much higher than that of chimpanzees. Due to the lack of direct sperm competition, it seems that human beings have relaxed their control over semen quality.
For species that do not have to directly experience sperm competition, the only possible explanation is that the large number of sperm is related to genetic diversity. JackCohen, a biologist at the University of Birmingham in the United Kingdom, pointed out in several rarely cited papers published more than 40 years ago that the number of sperm is related to the number of copies of chromosomes in the production process. In the process of meiosis, paired chromosomes exchange a large amount of genetic material through cross exchange. Cohen found that the more cross-exchanges between different species, the more sperm.