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Prenatal Hormones And Sexual Orientation
The hormonal theory of sexuality holds that, just as exposure to certain hormones plays a role in fetal sex differentiation, such exposure also influences the sexual orientation that emerges later in the adult. Prenatal hormones may be seen as the primary determinant of adult sexual orientation, or a co-factor with genes, biological factors and/or environmental and social conditions. Sex-typed behavior The hormonal theory of sexuality and gender identity holds that, just as exposure to certain hormones plays a role in fetal sex differentiation, such exposure also influences the sexual orientation and or gender identity that emerges later in the adult. Differences in brain structure that come about from chemical messengers and genes interacting on developing brain cells are believed to be the basis of sex differences in countless behaviors, including sexual orientation. Prenatal factors that affect or interfere with the interaction of these hormones on the developing brain can in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Differentiation
Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype. In many species, testicular or ovarian differentiation begins with appearance of Sertoli cells in males and granulosa cells in females. As male and female individuals develop from embryos into mature adults, sex differences at many levels develop, such as genes, chromosomes, gonads, hormones, anatomy, and psyche. Beginning with determination of sex by genetic and/or environmental factors, humans and other organisms proceed down different pathways of differentiation as they grow and develop. These processes are not fixed, and can change over one organism's lifetime or over many generations evolutionarily. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisexuality
Bisexuality is a romantic or sexual attraction or behavior toward both males and females, or to more than one gender. It may also be defined to include romantic or sexual attraction to people regardless of their sex or gender identity, which is also known as '' pansexuality.'' The term ''bisexuality'' is mainly used in the context of human attraction to denote romantic or sexual feelings toward both men and women, and the concept is one of the three main classifications of sexual orientation along with heterosexuality and homosexuality, all of which exist on the heterosexual–homosexual continuum. A bisexual identity does not necessarily equate to equal sexual attraction to both sexes; commonly, people who have a distinct but not exclusive sexual preference for one sex over the other also identify themselves as bisexual. Scientists do not know the exact cause of sexual orientation, but they theorize that it is caused by a complex interplay of genetic, hormonal, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethylstilbestrol
Diethylstilbestrol (DES), also known as stilbestrol or stilboestrol, is a nonsteroidal estrogen medication, which is presently rarely used. In the past, it was widely used for a variety of indications, including pregnancy support for those with a history of recurrent miscarriage, hormone therapy for menopausal symptoms and estrogen deficiency, treatment of prostate cancer and breast cancer, and other uses. By 2007, it was only used in the treatment of prostate cancer and breast cancer. In 2011, Hoover and colleagues reported on adverse health outcomes linked to DES including infertility, miscarriage, ectopic pregnancy, preeclampsia, preterm birth, stillbirth, infant death, menopause prior to age 45, breast cancer, cervical cancer, and vaginal cancer. While most commonly taken by mouth, DES was available for use by other routes as well, for instance, vaginal, topical, and by injection. DES is an estrogen, or an agonist of the estrogen receptors, the biological target ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INAH3
INAH-3 is the short form for the third interstitial nucleus of the anterior hypothalamus, and is the sexually dimorphic nucleus of humans. The INAH-3 is significantly larger in males than in females regardless of age and larger in heterosexual males than in homosexual males and heterosexual females. Research The term INAH (interstitial nuclei of the anterior hypothalamus), first proposed in 1989 by a group of the University of California at Los Angeles, refers to 4 previously undescribed cell groups of the preoptic-anterior hypothalamic area (PO-AHA) of the human brain, which is a structure that influences gonadotropin secretion, maternal behavior, and sexual behavior in several mammalian species. There are four nuclei in the PO-AHA (INAH1-4). One of these nuclei, INAH-3, was found to be 2.8 times larger in the male brain than in the female brain regardless of age. A study authored by Simon LeVay and published in the journal ''Science'' suggests that the region is an important b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oregon State University
Oregon State University (OSU) is a public land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degrees. It has the 10th largest engineering college in the nation for 2022. Undergraduate enrollment for all colleges combined averages close to 32,000, making it the state's largest university. Out-of-state students make up over one-quarter of undergraduates and an additional 5,500 students are engaged in graduate coursework through the university. Since its founding, over 272,000 students have graduated from OSU. It is classified among "Doctoral Universities – Very high research activity". Chartered as a land-grant university initially, OSU became one of the four inaugural members of the Sea Grant in 1971. It joined the Space Grant and Sun Grant research consortia in 1991 and 2003, respectively, making it the first public university and one of just four in total to attain me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simon LeVay
Simon LeVay (born 28 August 1943 in Oxford, England) is a British-American neuroscientist. He received a bachelor's degree in natural sciences from the University of Cambridge in 1966, a Ph.D. in Neuroanatomy at the University of Göttingen in Germany, and completed his post doctoral fellowship at Harvard Medical School in 1974. LeVay held positions in neurobiology at the Harvard Medical School from 1974 to 1984. He then worked at the Salk Institute for Biological Studies from 1984 to 1993 while holding an Associate Professorship in Biology at the University of California, San Diego. Much of his early work focused on the visual cortex in animals. While working at the Salk Institute for Biological Studies, LeVay published an article in Science that compared the size of the "Interstitial Nucleus of the Anterior Hypothalamus" ( INAH3) in a group of gay men to a group of straight men and women. This was the first scientific study ever published that showed brain differences based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suprachiasmatic Nucleus
The suprachiasmatic nucleus or nuclei (SCN) is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle. The mouse SCN contains approximately 20,000 neurons. The SCN interacts with many other regions of the brain. It contains several cell types and several different peptides (including vasopressin and vasoactive intestinal peptide) and neurotransmitters. Neuroanatomy The SCN is situated in the anterior part of the hypothalamus immediately dorsal, or ''superior'' (hence supra) to the optic chiasm (CHO) bilateral to (on either side of) the third ventricle. The nucleus can be divided into ventrolateral and dorsolateral portions, also known as the core and shell, respectively. These regions differ in their expression of the clock genes, the core expresses them in response to stimuli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uterus
The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The uterus is a hormone-responsive sex organ that contains glands in its lining that secrete uterine milk for embryonic nourishment. In the human, the lower end of the uterus, is a narrow part known as the isthmus that connects to the cervix, leading to the vagina. The upper end, the body of the uterus, is connected to the fallopian tubes, at the uterine horns, and the rounded part above the openings to the fallopian tubes is the fundus. The connection of the uterine cavity with a fallopian tube is called the uterotubal junction. The fertilized egg is carried to the uterus along the fallopian tube. It will have divided on its journey to form a blastocyst that will implant itself into the lining of the uterus – the endometrium, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolytic Disease Of The Newborn
Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis foetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules (one of the five main types of antibodies) produced by the mother pass through the placenta. Among these antibodies are some which attack antigens on the red blood cells in the fetal circulation, breaking down and destroying the cells. The fetus can develop reticulocytosis and anemia. The intensity of this fetal disease ranges from mild to very severe, and fetal death from heart failure (hydrops fetalis) can occur. When the disease is moderate or severe, many erythroblasts (immature red blood cells) are present in the fetal blood, earning these forms of the disease the name ''erythroblastosis fetalis'' (). HDFN represents a breach of immune privilege for the fetus or some other form of impairment of the immune tolerance in pregnancy. Various types of H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handedness And Sexual Orientation
A relationship between handedness and sexual orientation has been suggested by a number of researchers, who report that heterosexual individuals are somewhat more likely to be right-handed than are homosexual individuals. The relationship between handedness and sexual orientation has been suggested within both sexes and may reflect the biological etiology of sexual orientation; work by Ray Blanchard has linked the relationship to the fraternal birth order effect, which suggests that a man with several older biological brothers is more likely to be homosexual. The psychologist Chris McManus and a team of researchers weighed in on the relationship to homosexuality and concluded: Studies Lalumière ''et al''., 2000 meta-analysis Lalumière ''et al''. conducted a meta-analysis of 20 studies with a total of 6,987 homosexual and 16,423 heterosexual participants. They found that homosexual men had a 34% greater odds of not being right-handed, and homosexual women ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Y-chromosone
The Y chromosome is one of two sex chromosomes (allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or absence of Y that determines the male or female sex of offspring produced in sexual reproduction. In mammals, the Y chromosome contains the gene SRY, which triggers male development. The DNA in the human Y chromosome is composed of about 59 million base pairs, making it similar in size to chromosome 19. The Y chromosome is passed only from father to son. With a 30% difference between humans and chimpanzees, the Y chromosome is one of the fastest-evolving parts of the human genome. The human Y chromosome carries an estimated 100–200 genes, with between 45 and 73 of these being protein-coding. All single-copy Y-linked genes are hemizygous (present on only one chromosome) except in cases of aneuploidy such as XYY syndrome or XXYY syndrome. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
