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Pubarche
Pubarche refers to the first appearance of pubic hair at puberty. Pubarche is one of the physical changes of puberty and can occur independently of complete puberty. Pubarche usually results from rising levels of androgen and not estrogens in females, and androgens in males from the adrenal glands, ovaries, or testes but may also result from exposure to an anabolic steroid. When pubarche occurs prematurely (in early or mid-childhood), it is referred to as ''premature pubarche'' or precocious puberty and may warrant an evaluation. Premature adrenarche is the most common cause of premature pubarche. Early occurrences can arise due to congenital adrenal hyperplasia, androgen-producing tumors of the adrenals or gonads. When adrenarche, central puberty, and all pathologic conditions have been excluded, the term ''isolated premature pubarche'' is used to describe the unexplained development of pubic hair at an early age without other hormonal or physical changes of puberty. Average age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thelarche
Thelarche, also known as breast budding, is the onset of secondary breast development, often representing the beginning of pubertal development. It is the stage at which male and female breasts differentiate due to variance in hormone levels; however, some males have a condition in which they develop breasts, termed gynecomastia. Thelarche typically occurs between the ages of 8 and 13 years with significant variation between individuals. However, the initial growth of breast tissue occurs during fetal development regardless of sex. Usually, females experience menarche about two years after thelarche has begun, with complete breast development from thelarche to adult breasts, taking between 2 and 4 years. Moreover, puberty is considered delayed if breast development does not start before age 13 or if a female has not had her first period (menarche) within three years of thelarche. Additionally, secondary breast development occurring before the age of 7 or 8 years could be a sign of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menarche
Menarche ( ; ) is the first menstrual cycle, or first menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fertility. Girls experience menarche at different ages. Having menarche occur between the ages of 9–16 in the west is considered normal.US National Health Statistics Report September 2020 Canadian psychological researcher Niva Piran claims that menarche or the perceived average age of puberty is used in many cultures to separate girls from activity with boys, and to begin confinement as a woman and future wife. The timing of menarche is influenced by female , as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pubic Hair
Pubic hair is terminal body hair that is found in the genital area of adolescent and adult humans. The hair is located on and around the sex organs and sometimes at the top of the inside of the thighs. In the pubic region around the pubis bone, it is known as a ''pubic patch''. Pubic hair is also found on the scrotum in the male and on the vulva in the female. Although fine vellus hair is present in the area in childhood, pubic hair is considered to be the heavier, longer and coarser hair that develops during puberty as an effect of rising levels of androgens in males and estrogens in females. Pubic hair differs from other hair on the body and is a secondary sex characteristic. Many cultures regard pubic hair as erotic, and in most cultures it is associated with the genitals, which both men and women are expected to keep covered at all times. In some cultures, it is the norm for pubic hair to be removed, especially of females; the practice is regarded as part of personal hygie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Genitalia Five Tanner Stages
Male (Mars symbol, symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot sexual reproduction, reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and Asexual reproduction, asexually. Most male mammals, including male humans, have a Y chromosome, which codes for the production of larger amounts of testosterone to develop male reproductive organs. Not all species share a common sex-determination system. In most animals, including Homo sapiens, humans, sex is determined genetics, genetically; however, species such as ''Cymothoa exigua'' change sex depending on the number of females present in the vicinity. In humans, the word ''male'' can also be used to refer to gender in the social sense of gender role or gender identity. Overview The existence of separate sexes has evol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Development
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Human development may refer to: * Development of the human body * Developmental psychology * Human development (economics) * Human Development Index, an index used to rank countries by level of human development * Human evolution, the prehistoric process leading to the modern human species * ''Human Development'' (journal), a journal published by Karger See also * Human population growth Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developmental Stages
Stages of development may refer to: Biology *Developmental biology, the study of the process by which animals and plants grow and develop *Prenatal development, also called fetal development, or embryology *Human development (biology), the process of growing to maturity. In biological terms, this entails growth from a one-celled zygote to an adult human being Economics *Economic growth, the increase in the amount of the goods and services produced by an economy over time *Input-output model, a quantitative economic technique that represents the interdependencies between different branches of a national economy or different regional economies * IS/LM model, a macroeconomic tool that demonstrates the relationship between interest rates and real output in the goods and services market and the money market *Rostovian take-off model *Exogenous growth model *Endogenous growth theory, holds that economic growth is primarily the result of endogenous and not external forces *Dual-sector ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermarche
Spermarche—also known as semenarche—is the beginning of development of sperm in boys' testicles at puberty.''Adolescence and Emerging Adulthood: A Cultural Approach'', Jeffrey Jensen Arnett, N.J.: Prentice-Hall, 3rd edition, 2006. It is the counterpart of menarche in girls. Depending on their upbringing, cultural differences, and prior sexual knowledge, boys may have different reactions to spermarche, ranging from fear to excitement. Spermarche is one of the first events in the life of a male leading to sexual maturity. It occurs at the time when the secondary sex characteristics are just beginning to develop. The age when spermarche occurs is not easy to determine. However, researchers have tried to determine the age in various populations by taking urine samples of boys and determining the presence of spermatozoa. The presence of sperm in urine is referred to as spermaturia. Age of occurrence ''1986 Year Book of Pediatrics'' stated "Fish irsch - n.n.et al. (J. Adolesc. H ... [...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] |
Androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes the embryological development of the primary male sex organs, and the development of male secondary sex characteristics at puberty. Androgens are synthesized in the testes, the ovaries, and the adrenal glands. Androgens increase in both males and females during puberty. The major androgen in males is testosterone. Dihydrotestosterone (DHT) and androstenedione are of equal importance in male development. DHT ''in utero'' causes differentiation of the penis, scrotum and prostate. In adulthood, DHT contributes to balding, prostate growth, and sebaceous gland activity. Although androgens are commonly thought of only as male sex hormones, females also have them, but at lower levels: they function in libido and sexual arousal. Also, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonad
A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sperm in the form of spermatozoa. The female gonad, the ovary, produces egg cells. Both of these gametes are haploid cells. Some hermaphroditic animals have a type of gonad called an ovotestis. Evolution It is hard to find a common origin for gonads, but gonads most likely evolved independently several times. Regulation The gonads are controlled by luteinizing hormone and follicle-stimulating hormone, produced and secreted by gonadotropes or gonadotrophins in the anterior pituitary gland. This secretion is regulated by gonadotropin-releasing hormone produced in the hypothalamus. Development Gonads start developing as a common primordium (an organ in the earliest stage of development), in the form of genital ridges, which are only l ... [...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] |
