Both men and women are born with a pair of breasts, and if the breasts of women bear the heavy responsibility of breastfeeding offspring, then the breasts of men seem to have no other role than to decorate and distinguish between the front and the back.
But, is this really the case?
The sperm and egg combine to form a fertilized egg, in which the father and mother each provide 22 autosomes and 1 sex chromosome, "spelling" a complete set of 23 pairs of chromosomes for the baby.
In the early embryonic stage, the sex is not yet developed, everything is developed according to the instructions of the genes in the chromosomes, and the genes of the nipple and mammary gland are hidden in those regular chromosomes.
So whether it's a boy or a girl, babies will start to grow nipples at the 3rd to 4th week of their mother's womb and continue to develop.
But by the 6th week, the baby's breast development stops because the Y chromosome begins to release androgens that inhibit breast development. And estrogen can promote breast development, which is why women's breasts can continue to develop for a long time.
Therefore, breasts are not the key to distinguishing between sexes, it is a normal physiological structure of human beings, but under the influence of androgens, men's breasts stop developing in the embryonic stage.
Although the male breast does not develop at an early age, it is not useless, it can add spice to the life of the couple, and even save lives.
Research data shows that cardiopulmonary resuscitation within 4 minutes after cardiac arrest can achieve a success rate of 50%, if more than 6 minutes, the success rate is only 4%, the key to survival is "fast".
Chest compressions are the most critical step in cardiopulmonary resuscitation, and it is generally necessary to perform strong compressions on the middle and lower sternum1 3 in order to squeeze the heart deep into the chest cavity of the body and restore the blood supply to the whole body.
How do you determine the position of the middle and lower sternum 1 3?This depends on the nipple, generally the midpoint of the line between the two nipples is lower, which is the part that needs to be pressed, if there is no nipple as a reference coordinate, it is difficult for inexperienced veterans to quickly carry out rescue.
A survey in the Journal of Sexual Medicine showed that 82% of women, as well as 52% of men, experienced faster sexual arousal in their couple's life through the act of stimulating their breasts.
Because the nipples belong to the sexual excitement areas of both men and women, it is easy to provoke sexual desire through appropriate external stimulation, and some more sensitive men, just stimulating the nipples, can cause a strong reaction in the lower body.
Compared with women, men rarely care about their breasts, and sometimes they may not be able to detect it in time when they are sick.
Some men are proud of the "pectoralis major muscle" may be gynecomastia, which is a benign hyperplasia of breast tissue, often caused by an imbalance between estrogen and androgen in the chest, which may be endocrine diseases, decreased function, tumors, excessive intake of exogenous estrogen, etc., resulting in unilateral or bilateral enlargement of the breast.
However, most gynecomastia is a self-limiting disease, that is, it can resolve spontaneously after six months to one year, and if the chest is enlarged in the early stage, drugs can also be used**.
But not all male breast diseases are so "easy to say", breast cancer is one of the most malignant diseases of male breasts.
As long as men have breast tissue, they cannot completely get rid of the risk of cancer, and long-term radiation exposure, sex chromosome abnormalities, high estrogen levels, and family history of breast cancer can all make men's breasts cancerous.
Although the incidence of male breast cancer is low (accounting for about 1% of breast cancer cases), due to the lack of attention, it is basically advanced at the first examination, and the mortality rate is relatively high.
A large-scale study in the Journal of the American Medical Association Oncology, a top international journal in oncology, showed that the mortality rate of male breast cancer patients was 19% higher than that of women.
Therefore, if male compatriots find that their breasts are inexplicably enlarged, lumps, discharge, inverted nipples, ** cellulite lesions, etc., they should go to the breast department for examination in time, and make a clear diagnosis as soon as possible through palpation, breast color ultrasound, mammography, etc.
Many men are because they ignore the changes in their breasts, resulting in the discovery of breast diseases, often in the middle and late stages, which is more difficult and the prognosis is worse.
References:1]levin r， meston c. nipple/breast stimulation and sexual arousal in young men and women. j sex med. 2006 may;3(3)：450-4. doi： 10.1111/j.1743-6109.2006.00230.x. pmid： 16681470.
2]gucalp a， traina ta， eisner jr， parker js， selitsky sr， park bh， elias ad， baskin-bey es， cardoso f. male breast cancer： a disease distinct from female breast cancer. breast cancer res treat. 2019 jan;173(1)：37-48. doi： 10.1007/s10549-018-4921-9. epub 2018 sep 28. pmid： 30267249; pmcid： pmc7513797.
3] Cai Jinglong, Yang Jiafeng. Pathological research status of gynecomastia[J].Chinese Journal of Aesthetic Plastic Surgery, 2005, 016(003):169-171