WHY DOES MY BREAST HURT? скачать в хорошем качестве

WHY DOES MY BREAST HURT?

. Chapters 0:00 Introduction 0:45 What is cyclic breast pain? 1:05 Characteristics of cyclic breast pain are: 1:29 What is noncyclic breast pain? 2:16 Symptoms of noncyclic breast pain include 2:33 How is breast pain treated? The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and secretes milk to feed infants.[2] Subcutaneous fat covers and envelops a network of ducts that converge on the nipple, and these tissues give the breast its size and shape. At the ends of the ducts are lobules, or clusters of alveoli, where milk is produced and stored in response to hormonal signals.[3] During pregnancy, the breast responds to a complex interaction of hormones, including estrogens, progesterone, and prolactin, that mediate the completion of its development, namely lobuloalveolar maturation, in preparation of lactation and breastfeeding. Humans are the only animals with permanent breasts. At puberty, estrogens, in conjunction with growth hormone, cause permanent breast growth in female humans. This happens only to a much lesser extent in other primates—breast development in other primates generally only occurs with pregnancy. Along with their major function in providing nutrition for infants, female breasts have social and sexual characteristics. Breasts have been featured in ancient and modern sculpture, art, and photography. They can figure prominently in the perception of a woman's body and sexual attractiveness. A number of cultures associate breasts with sexuality and tend to regard bare breasts in public as immodest or indecent. Breasts, especially the nipples, are an erogenous zone. The English word breast derives from the Old English word brēost ('breast, bosom') from Proto-Germanic *breustam (breast), from the Proto-Indo-European base bhreus– (to swell, to sprout).[4] The breast spelling conforms to the Scottish and North English dialectal pronunciations.[5] The Merriam-Webster Dictionary states that "Middle English brest, [comes] from Old English brēost; akin to Old High German brust..., Old Irish brú [belly], [and] Russian bryukho"; the first known usage of the term was before the 12th century.[6] A large number of colloquial terms for breasts are used in English, ranging from fairly polite terms to vulgar or slang.[7] Some vulgar slang expressions may be considered to be derogatory or sexist to women.[8] Evolutionary development Humans are the only mammals whose breasts become permanently enlarged after sexual maturity (known in humans as puberty). The reason for this evolutionary change was unknown.[9] Several hypotheses have been put forward: A link has been proposed to processes for synthesizing the endogenous steroid hormone precursor dehydroepiandrosterone which takes place in fat rich regions of the body like the buttocks and breasts. These contributed to human brain development and played a part in increasing brain size. Breast enlargement may for this purpose may have occurred as early as Homo ergaster (1.7–1.4 MYA).[10] Other breast formation hypotheses may have then taken over as principal drivers.[11][12][13] It has been suggested by zoologists Avishag and Amotz Zahavi that the size of the human breasts can be explained by the handicap theory of sexual dimorphism. This would see the explanation for larger breasts as them being an honest display of the women's health and ability to grow and carry them in her life. Prospective mates can then evaluate the genes of a potential mate for their ability to sustain her health even with the additional energy demanding burden she is carrying.[14][10] The zoologist Desmond Morris describes a sociobiological approach in his popular science book The Naked Ape. He suggests, by making comparisons with the other primates, that breasts evolved to replace swelling buttocks as a sex signal, of ovulation. He notes how humans have, relatively speaking, large penises as well as large breasts. Furthermore, early humans adopted bipedalism and face-to-face coitus. He therefore suggested enlarged sexual signals helped maintain the bond between a mated male and female even though they performed different duties and therefore were separated for lengths of time.[15][10][16] The study The Evolution of the Human Breast (2001) proposed that the rounded shape of a woman's breast evolved to prevent the sucking infant offspring from suffocating while feeding at the teat; that is, because of the human infant's small jaw, which did not project from the face to reach the nipple, he or she might block the nostrils against the mother's breast if it were of a flatter form (cf. common chimpanzee). Theoretically, as the human jaw receded into the face, the woman's body compensated with round breasts.[17]