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Breasts
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. 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. 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 lesse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that breastfeeding begin within the first hour of a baby's life and continue as often and as much as the baby wants. Health organizations, including the WHO, recommend breastfeeding exclusively for six months. This means that no other foods or drinks, other than vitamin D, are typically given. WHO recommends exclusive breastfeeding for the first 6 months of life, followed by continued breastfeeding with appropriate complementary foods for up to 2 years and beyond. Of the 135 million babies born every year, only 42% are breastfed within the first hour of life, only 38% of mothers practice exclusive breastfeeding during the first six months, and 58% of mothers continue breastfeeding up to the age of two years and beyond. Breastfeeding has a numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nipple
The nipple is a raised region of tissue on the surface of the breast from which, in females, milk leaves the breast through the lactiferous ducts to feed an infant. The milk can flow through the nipple passively or it can be ejected by smooth muscle contractions that occur along with the ductal system. The nipple is surrounded by the areola, which is often a darker colour than the surrounding skin. A nipple is often called a teat when referring to non-humans. Nipple or teat can also be used to describe the flexible mouthpiece of a baby bottle. In humans, the nipples of both males and females can be stimulated as part of sexual arousal. In many cultures, human female nipples are sexualized, or "regarded as sex objects and evaluated in terms of their physical characteristics and sexiness." Anatomy In mammals, a nipple (also called mammary papilla or teat) is a small projection of skin containing the outlets for 15–20 lactiferous ducts arranged cylindrically around the tip. Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexuality
Human sexuality is the way people experience and express themselves sexually. This involves biological, psychological, physical, erotic, emotional, social, or spiritual feelings and behaviors. Because it is a broad term, which has varied with historical contexts over time, it lacks a precise definition. The biological and physical aspects of sexuality largely concern the human reproductive functions, including the human sexual response cycle. Someone's sexual orientation is their pattern of sexual interest in the opposite or same sex. Physical and emotional aspects of sexuality include bonds between individuals that are expressed through profound feelings or physical manifestations of love, trust, and care. Social aspects deal with the effects of human society on one's sexuality, while spirituality concerns an individual's spiritual connection with others. Sexuality also affects and is affected by cultural, political, legal, philosophical, moral, ethical, and religious ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in the body. Progesterone has a variety of important functions in the body. It is also a crucial metabolic intermediate in the production of other endogenous steroids, including the sex hormones and the corticosteroids, and plays an important role in brain function as a neurosteroid. In addition to its role as a natural hormone, progesterone is also used as a medication, such as in combination with estrogen for contraception, to reduce the risk of uterine or cervical cancer, in hormone replacement therapy, and in feminizing hormone therapy. It was first prescribed in 1934. Biological activity Progesterone is the most important progestogen in the body. As a potent agonist of the nuclear progesterone receptor (nPR) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Areola
The human areola (''areola mammae'', or ) is the pigmented area on the breast around the nipple. Areola, more generally, is a small circular area on the body with a different histology from the surrounding tissue, or other small circular areas such as an inflamed region of skin. The mature human female nipple has several small openings arranged radially around the tip of the lactiferous ducts from which milk is released during lactation. Other small openings in the areola are sebaceous glands, also known as areolar glands. Shade The areolae can range from pink to red to brown to dark brown or nearly black, but generally tend to be paler among people with lighter skin tones and darker among people with darker skin tones. A reason for the differing color may be to make the nipple area more visible to the infant. Size and shape The size and shape of areolae and nipples are also highly variable, with those of women usually being larger than those of men and prepubescent girl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erogenous Zone
An erogenous zone (from Greek , ''érōs'' "love"; and English ''-genous'' "producing", from Greek , ''-genḗs'' "born") is an area of the human body that has heightened sensitivity, the stimulation of which may generate a sexual response, such as relaxation, sexual fantasies, sexual arousal and orgasm. Erogenous zones are located all over the human body, but the sensitivity of each varies, and depends on concentrations of nerve endings that can provide pleasurable sensations when stimulated. The touching of another person's erogenous zone is regarded as an act of physical intimacy. Whether a person finds stimulation in these areas to be pleasurable or objectionable depends on a range of factors, including their level of arousal, the circumstances in which it takes place, the cultural context, the nature of the relationship between the partners, and the partners' personal histories. Erogenous zones may be classified by the type of sexual response that they generate. Many peo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Culture
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tylor, Edward. (1871). Primitive Culture. Vol 1. New York: J.P. Putnam's Son Culture is often originated from or attributed to a specific region or location. Humans acquire culture through the learning processes of enculturation and socialization, which is shown by the diversity of cultures across societies. A cultural norm codifies acceptable conduct in society; it serves as a guideline for behavior, dress, language, and demeanor in a situation, which serves as a template for expectations in a social group. Accepting only a monoculture in a social group can bear risks, just as a single species can wither in the face of environmental change, for lack of functional responses to the change. Thus in military culture, valor is counted a typica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Attraction
Sexual attraction is attraction on the basis of sexual desire or the quality of arousing such interest. Sexual attractiveness or sex appeal is an individual's ability to attract other people sexually, and is a factor in sexual selection or mate choice. The attraction can be to the physical or other qualities or traits of a person, or to such qualities in the context where they appear. The attraction may be to a person's aesthetics or movements or to their voice or smell, among other things. The attraction may be enhanced by a person's adornments, clothing, perfume or style. It can be influenced by individual genetic, psychological, or cultural factors, or to other, more amorphous qualities. Sexual attraction is also a response to another person that depends on a combination of the person possessing the traits and on the criteria of the person who is attracted. Though attempts have been made to devise objective criteria of sexual attractiveness and measure it as one of several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age. This is just over nine months. Counting by fertilization age, the length is about 38 weeks. Pregnancy is "the presence of an implanted human embryo or fetus in the uterus"; implantation occurs on average 8–9 days after fertilization. An '' embryo'' is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term ''fetus'' is used until birth. Signs an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast Development
Breast development, also known as mammogenesis, is a complex biological process in primates that takes place throughout a female's life. It occurs across several phases, including prenatal development, puberty, and pregnancy. At menopause, breast development ceases and the breasts atrophy. Breast development results in prominent and developed structures on the chest known as breasts in primates, which serve primarily as mammary glands. The process is mediated by an assortment of hormones (and growth factors), the most important of which include estrogen, progesterone, prolactin, and growth hormone. Biochemistry Hormones The master regulators of breast development are the steroid hormones, estrogen and progesterone, growth hormone (GH), mostly via its secretory product, insulin-like growth factor 1 (IGF-1), and prolactin. These regulators induce the expression of growth factors, such as amphiregulin, epidermal growth factor (EGF), IGF-1, and fibroblast growth factor (FGF), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Hormone
Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in human development. GH also stimulates production of IGF-1 and increases the concentration of glucose and free fatty acids. It is a type of mitogen which is specific only to the receptors on certain types of cells. GH is a 191-amino acid, single-chain polypeptide that is synthesized, stored and secreted by somatotropic cells within the lateral wings of the anterior pituitary gland. A recombinant form of hGH called somatropin (INN) is used as a prescription drug to treat children's growth disorders and adult growth hormone deficiency. In the United States, it is only available legally from pharmacies by prescription from a licensed health care provider. In recent years in the United States, some health care providers are prescribing growth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult body has been developed. Before puberty, the external sex organs, known as primary sexual characteristics, are sex characteristics that distinguish boys and girls. Puberty leads to sexual dimorphism through the development of the secondary sex characteristics, which further distinguish the sexes. On average, girls begin puberty at ages 10–11 and complete puberty at ages 15–17; boys generally begin puberty at ages 11–12 and complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
