A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to impact the behavior of the receiving individuals. There are alarm pheromones, food trail pheromones, sex pheromones, many others that affect behavior or physiology. Pheromones are used from basic unicellular prokaryotes to complex multicellular eukaryotes, their use among insects has been well documented. In addition, some vertebrates and ciliates communicate by using pheromones; the portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω pheroo and ὁρμων hormon. Pheromones are sometimes classified as ecto-hormones, they were researched earlier by various scientists, including Jean-Henri Fabre, Joseph A. Lintner, Adolf Butenandt, ethologist Karl von Frisch who called them various names, like for instance "alarm substances".
These chemical messengers are transported outside of the body and affect neurocircuits, including the autonomous nervous system with hormone or cytokine mediated physiological changes, inflammatory signaling, immune system changes and/or behavioral change in the recipient. They proposed the term to describe chemical signals from conspecifics that elicit innate behaviors soon after the German biochemist Adolf Butenandt had characterized the first such chemical, bombykol, a chemically well-characterized pheromone released by the female silkworm to attract mates. Aggregation pheromones function in mate selection, overcoming host resistance by mass attack, defense against predators. A group of individuals at one location is referred to as an aggregation, whether consisting of one sex or both sexes. Male-produced sex attractants have been called aggregation pheromones, because they result in the arrival of both sexes at a calling site and increase the density of conspecifics surrounding the pheromone source.
Most sex pheromones are produced by the females. Aggregation pheromones have been found in members of the Coleoptera, Hemiptera and Orthoptera. In recent decades, the importance of applying aggregation pheromones in the management of the boll weevil, stored product weevils, Sitophilus granarius, Sitophilus oryzae, pea and bean weevil has been demonstrated. Aggregation pheromones are among the most ecologically selective pest suppression methods, they are nontoxic and effective at low concentrations. Some species release a volatile substance when attacked by a predator that can trigger flight or aggression in members of the same species. For example, Vespula squamosa use alarm pheromones to alert others to a threat. In Polistes exclamans, alarm pheromones are used as an alert to incoming predators. Pheromones exist in plants: Certain plants emit alarm pheromones when grazed upon, resulting in tannin production in neighboring plants; these tannins make the plants less appetizing for the herbivore.
Epideictic pheromones are different from territory pheromones. Fabre observed and noted how "females who lay their eggs in these fruits deposit these mysterious substances in the vicinity of their clutch to signal to other females of the same species they should clutch elsewhere." It may be helpful to note that the word epideictic, having to do with display or show, has a different but related meaning in rhetoric, the human art of persuasion by means of words. Releaser pheromones are pheromones. For example, some organisms use powerful attractant molecules to attract mates from a distance of two miles or more. In general, this type of pheromone elicits a rapid response, but is degraded. In contrast, a primer pheromone has a longer duration. For example, rabbit release mammary pheromones that trigger immediate nursing behavior by their babies. Signal pheromones cause short-term changes, such as the neurotransmitter release that activates a response. For instance, GnRH molecule functions as a neurotransmitter in rats to elicit lordosis behavior.
Primer pheromones trigger a change of developmental events. Laid down in the environment, territorial pheromones mark the boundaries and identity of an organism's territory. In cats and dogs, these hormones are present in the urine, which they deposit on landmarks serving to mark the perimeter of the claimed territory. In social seabirds, the preen gland is used to mark nests, nuptial gifts, territory boundaries with behavior described as'displacement activity'. Social insects use trail pheromones. For example, ants mark their paths with pheromones consisting of volatile hydrocarbons. Certain ants lay down an initial trail of pheromones; this trail serves as a guide. As long as the food source remains available, visiting ants will continuously renew the pheromone trail; the pheromone requires continuous renewal. When the food supply begins to dwindle, the trail-making ceases. In at least one species of ant, trails that no longer lead to food are marked with a repellent pheromone; the Eciton burchellii species provides an example of using pheromones to mark and maintain foraging paths.
When species of wasps such as Polybia sericea found new nests, they use pheromones to lead the rest of the
The human areola is the pigmented area on the breast around the nipple. Areola, more 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 nipple from which milk is released during lactation. Other small openings in the areola are sebaceous glands, known as Montgomery's glands; the areolae can range from pink to red to chocolate brown to dark brown or nearly black, but 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; the size and shape of areolae and nipples are highly variable, with those of women being larger than those of men and prepubescent girls. Human areolae are circular in shape, but many women with large areolae are noticeably elliptical; the average diameter of male areolae is around 28.0 mm. Sexually mature women have an average of 38.1 mm, but sizes can exceed 100 mm.
Lactating women, women with large breasts, may have larger areolae. A function of the specialized dermis of the areola is to protect the regular breast skin from wear and irritation. Infants sometimes areolae by latching-on of the infant. Another function of an areola is to house slowly-adapting mechanoreceptors that trigger oxytocin excretion during nursing; the size of the areola implies a need to protect a larger area than the nipple due to many factors that are not known. Rated according to the Tanner scale of physical development, in stage four, the areolae are raised. In stage five, they are no longer raised. Breastfeeding by the baby innervates adapting and adapting mechanoreceptors that are densely packed around the areolar region. Paget's disease of the breast is a malignant condition that outwardly may have the appearance of eczema, with skin changes involving the areola and nipple. List of specialized glands within the human integumentary system
A nerve is an enclosed, cable-like bundle of nerve fibres called axons, in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system; each axon within the nerve is an extension of an individual neuron, along with other supportive cells such as Schwann cells that coat the axons in myelin. Within a nerve, each axon is surrounded by a layer of connective tissue called the endoneurium; the axons are bundled together into groups called fascicles, each fascicle is wrapped in a layer of connective tissue called the perineurium. The entire nerve is wrapped in a layer of connective tissue called the epineurium. In the central nervous system, the analogous structures are known as tracts; each nerve is covered on the outside by a dense sheath of the epineurium. Beneath this is a layer of flat cells, the perineurium, which forms a complete sleeve around a bundle of axons.
Perineurial septae subdivide it into several bundles of fibres. Surrounding each such fibre is the endoneurium; this forms an unbroken tube from the surface of the spinal cord to the level where the axon synapses with its muscle fibres, or ends in sensory receptors. The endoneurium consists of an inner sleeve of material called the glycocalyx and an outer, meshwork of collagen fibres. Nerves are bundled and travel along with blood vessels, since the neurons of a nerve have high energy requirements. Within the endoneurium, the individual nerve fibres are surrounded by a low-protein liquid called endoneurial fluid; this acts in a similar way to the cerebrospinal fluid in the central nervous system and constitutes a blood-nerve barrier similar to the blood-brain barrier. Molecules are thereby prevented from crossing the blood into the endoneurial fluid. During the development of nerve edema from nerve irritation, the amount of endoneurial fluid may increase at the site of irritation; this increase in fluid can be visualized using magnetic resonance neurography, thus MR neurography can identify nerve irritation and/or injury.
Nerves are categorized into three groups based on the direction that signals are conducted: Afferent nerves conduct signals from sensory neurons to the central nervous system, for example from the mechanoreceptors in skin. Efferent nerves conduct signals from the central nervous system along motor neurons to their target muscles and glands. Mixed nerves contain both afferent and efferent axons, thus conduct both incoming sensory information and outgoing muscle commands in the same bundle. Nerves can be categorized into two groups based on where they connect to the central nervous system: Spinal nerves innervate much of the body, connect through the vertebral column to the spinal cord and thus to the central nervous system, they are given letter-number designations according to the vertebra through which they connect to the spinal column. Cranial nerves innervate parts of the head, connect directly to the brain, they are assigned Roman numerals from 1 to 12, although cranial nerve zero is sometimes included.
In addition, cranial nerves have descriptive names. Specific terms are used to describe their actions. A nerve that supplies information to the brain from an area of the body, or controls an action of the body is said to "innervate" that section of the body or organ. Other terms relate to whether the nerve affects the same side or opposite side of the body, to the part of the brain that supplies it. Nerve growth ends in adolescence, but can be re-stimulated with a molecular mechanism known as "Notch signaling". If the axons of a neuron are damaged, as long as the cell body of the neuron is not damaged, the axons would regenerate and remake the synaptic connections with neurons with the help of guidepost cells; this is referred to as neuroregeneration. The nerve begins the process by destroying the nerve distal to the site of injury allowing Schwann cells, basal lamina, the neurilemma near the injury to begin producing a regeneration tube. Nerve growth factors are produced causing many nerve sprouts to bud.
When one of the growth processes finds the regeneration tube, it begins to grow towards its original destination guided the entire time by the regeneration tube. Nerve regeneration is slow and can take up to several months to complete. While this process does repair some nerves, there will still be some functional deficit as the repairs are not perfect. A nerve conveys information in the form of electrochemical impulses carried by the individual neurons that make up the nerve; these impulses are fast, with some myelinated neurons conducting at speeds up to 120 m/s. The impulses travel from one neuron to another by crossing a synapse, the message is converted from electrical to chemical and back to electrical. Nerves can be categorized into two groups based on function: An afferent nerve fiber conducts sensory information from a sensory neuron to the central nervous system, where the information is processed. Bundles of fibres or axons, in the peripheral nervous system are called nerves, bundles of afferent fibers are known as sensory nerves.
An efferent nerve fiber conducts signals from a motor neuron in the central nervous system to muscles. Bundles of these fibres are known as efferent nerves; the nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body. In vertebrates it consists of two main par
Spin is an American music magazine founded in 1985 by publisher Bob Guccione, Jr. The magazine stopped running in print in 2012 and runs as a webzine, owned by the Billboard-Hollywood Reporter Media Group division of Valence Media. Spin was established in 1985. In its early years, the magazine was known for its broad music coverage with an emphasis on college rock, indie rock, the ongoing emergence of hip-hop; the magazine was bold, if sometimes haphazard. It pointedly provided a national alternative to Rolling Stone's more establishment-oriented style. Spin prominently placed newer artists such as R. E. M. Prince, Run-D. M. C. Eurythmics, Beastie Boys, Talking Heads on its covers and did lengthy features on established figures such as Bob Dylan, Keith Richards, Miles Davis, Lou Reed, Tom Waits, John Lee Hooker—Bart Bull's article on Hooker won the magazine its first major award. On a cultural level, the magazine devoted significant coverage to punk, alternative country, electronica and world music, experimental rock, jazz of the most adventurous sort, burgeoning underground music scenes, a variety of fringe styles.
Artists such as the Ramones, Patti Smith, Blondie, X, Black Flag, the former members of the Sex Pistols, The Clash, the early punk and New Wave movements were featured in Spin's editorial mix. Spin's extensive coverage of hip-hop music and culture that of contributing editor John Leland, was notable at the time. Editorial contributions by musical and cultural figures included Lydia Lunch, Henry Rollins, David Lee Roth and Dwight Yoakam; the magazine reported on cities such as Austin, Texas, or Glasgow, Scotland, as cultural incubators in the independent music scene. A 1990 article on the contemporary country blues scene brought R. L. Burnside to national attention for the first time. Coverage of American cartoonists, Japanese manga, monster trucks, the AIDS crisis, outsider artists, Twin Peaks, other non-mainstream cultural phenomena distinguished the magazine's dynamic early years. In late 1987, publisher Bob Guccione Jr.'s father, Bob Guccione Sr. abruptly shut the magazine down despite the fact that the two-year-old magazine was considered a success, with a newsstand circulation of 150,000.
Guccione Jr. was able to rally much of his staff, partner with former MTV president and David H. Horowitz, locate additional new investors and offices and after missing a month's publication, returned with a combined November–December issue. During this time, it was published by Camouflage Associates. In 1997, Guccione sold Spin to Miller Publishing. In 1994, two journalists working for the magazine were killed by a landmine while reporting on the Bosnian War in Bosnia and Herzegovina. A third, William T. Vollmann, was injured. In February 2006, Miller Publishing sold the magazine to a San Francisco-based company called the McEvoy Group LLC, the owner of Chronicle Books; that company formed Spin Media LLC as a holding company. The new owners replaced editor-in-chief Sia Michel with a former editor at Blender; the first issue to be published under his brief command was the July 2006 issue—sent to the printer in May 2006—which featured Beyoncé on the cover. Pemberton and Spin parted ways the next month, in June 2006.
The following editor, Doug Brod, was executive editor during Michel's tenure. For Spin's 20th anniversary, it published a book chronicling the prior two decades in music; the book has essays on grunge and emo, among other genres of music, as well as pieces on musical acts including Marilyn Manson, Tupac Shakur, R. E. M. Nirvana, Nine Inch Nails, Limp Bizkit, the Smashing Pumpkins. In February 2012, Spin relaunched the magazine in a larger, bi-monthly format and expanded its online presence, which covered reviews, extended editorials and features on up-and-coming talent. In July 2012, Spin was sold to Buzzmedia, which renamed itself SpinMedia; the September/October 2012 issue of Spin was the magazine's last print edition. In December 2016, Eldridge Industries acquired SpinMedia via the Hollywood Reporter-Billboard Media Group for an undisclosed amount. In 1995, Spin produced its first book, entitled Spin Alternative Record Guide, it compiled writings by 64 music critics on recording artists and bands relevant to the alternative music movement, with each artist's entry featuring their discography and albums reviewed and rated a score between one and ten.
According to Pitchfork Media's Matthew Perpetua, the book featured "the best and brightest writers of the 80s and 90s, many of whom started off in zines but have since become major figures in music criticism," including Rob Sheffield, Byron Coley, Ann Powers, Simon Reynolds, Alex Ross. Although the book was not a sales success, "it inspired a disproportionate number of young readers to pursue music criticism." After the book was published, its entry on 1960s folk artist John Fahey, written by Byron Coley, helped renew interest in Fahey's music, leading to interest from record labels and the alternative music scene. Contributors to Spin have included: SPIN began compiling year-end lists in 1990. Note: The 2000 album of the year was awarded to "your hard drive", acknowledging the impact that filesharing had on the music listening experience in 2000. Kid A was listed as the highest ranking given to an actual album. 1994 roadside attack on Spin magazine journalists Anon.. "Bibliography". In Ray, Michael.
Alternative, Hip-Hop and More: Music from the 1980s to Today. Britannica Educational Publishing. ISBN 1615309101. Mazmanian, Adam. "Library Journal". In White, William. Buyer's Guide. Bowker. Johnston, Maura. "Never Mind The Anglophilia, Here's The Queens Brothers". Idolator. Retrieved Jul
Nipple stimulation or breast stimulation is a common human sexual practice, either by itself or as part of other sexual activities. The practice may be by, people of any gender or sexual orientation. Adult women and men report that breast stimulation may be used to both initiate and enhance sexual arousal; the male or female breast and areola develop in the fetus and during infancy. At puberty, the male's breasts remain rudimentary but the female's develop further due to the presence of estrogen and progesterone, become much more sensitive than the male ones. Smaller female breasts, are more sensitive than larger ones. Nipple stimulation may produce sexual excitement. Erect nipples can be an indicator of an individual's sexual arousal, the individual's sexual partner may, as a result, find this erotically stimulating. Breasts, the nipples, are erogenous zones; the stimulation of women's nipples from suckling, including breastfeeding, promotes the production and release of oxytocin and prolactin.
Besides creating maternal feelings, it decreases a woman's anxiety and increases feelings of bonding and trust. Oxytocin is linked to sexual arousal and pair bonding, but researchers are divided on whether breastfeeding incites sexual feelings. Nipple erection may result during sexual arousal, or during breastfeeding. Nipple erection is due to the contraction of smooth muscle under the control of the autonomic nervous system, is a product of the pilomotor reflex which causes goose bumps. A survey in 2006 found that sexual arousal in about 82% of young females and 52% of young males occurs or is enhanced by direct stimulation of nipples, with only 7–8% reporting that it decreased their arousal. Few women report experiencing orgasm from nipple stimulation. Before Komisaruk et al.'s functional magnetic resonance research on nipple stimulation in 2011, reports of women achieving orgasm from nipple stimulation relied on anecdotal evidence. Komisaruk's study was the first to map the female genitals onto the sensory portion of the brain.
Breast fetishism Erotic lactation Fingering Mammary intercourse
The human anus is the external opening of the rectum. Two sphincters control the exit of feces from the body during an act of defecation, the primary function of the anus; these are the internal anal sphincter and the external anal sphincter, which are circular muscles that maintain constriction of the orifice and which relaxes as required by normal physiological functioning. The inner sphincter is involuntary and the outer is voluntary, it is located behind the perineum, located behind the vagina in females and behind the scrotum in males. With anal sex, the anus can play a role in sexuality. Attitudes towards anal sex vary and it is illegal in some countries; the anus is considered a taboo part of the body, it is known by a large number of vulgar slang terms. The anus is the site of potential infections and other conditions, including cancer; the traditional polite synonym for anus was fundament, though this euphemism is heard now that medical terms are acceptable. The anus is the final component of the gastrointestinal tract, directly continues from the rectum.
The anus passes through the pelvic floor. The anus is surrounded by muscles; the top and bottom of the anus are surrounded by the internal and external anal sphincters, two muscular rings which control defecation. The anus is surrounded in its length by folds called anal valves, which converge at a line known as the pectinate line; this represents the point of the ectoderm in the embryo. Below this point, the mucosa of the internal anus becomes skin; the pectinate line is the division between the internal and external anus. The anus receives blood from the inferior rectal artery and innervation from the inferior rectal nerves, which branch from the pudendal nerve; the pseudostratified columnar epithelium of the gastrointestinal tract transitions to stratified squamous epithelium at the pectinate line. The stratified squamous epithelium accumulates sebaceous and apocrine glands. During puberty, as testosterone triggers androgenic hair growth on the body, pubic hair begins to appear around the anus.
Although sparse, it fills out by the end of puberty, if not earlier. However, in some genetic populations androgenic hair is less common. Intra-rectal pressure builds as the rectum fills with feces, pushing the feces against the walls of the anal canal. Contractions of abdominal and pelvic floor muscles can create intra-abdominal pressure which further increases intra-rectal pressure; the internal anal sphincter responds to the pressure by relaxing, thus allowing the feces to enter the canal. The rectum shortens as feces are pushed into the anal canal and peristaltic waves push the feces out of the rectum. Relaxation of the internal and external anal sphincters allows the feces to exit from the anus as the levator ani muscles pull the anus up over the exiting feces. Birth defects, including imperforation, Tailgut cyst Fistula and anal fissure Hemorrhoids Anal abscesses Sexually transmitted infections Anal warts called "anal condyloma" Anal cancer called "anal carcinoma", Anal intraepithelial neoplasia Itchiness, called Pruritus ani Trauma.
In psychology, the Freudian term anal fixation is used. The anus has a high concentration of nerve endings and can be an erogenous zone, which can make anal intercourse pleasurable if performed properly; the pudendal nerve that branches to supply the external anal sphincter branches to the dorsal nerve of the clitoris and the dorsal nerve of the penis. Sigmund Freud's theory of psychosexual development, for example, described an anal stage, hypothesizing that toddlers derive pleasure from retaining and expelling feces; this is the source of the term "anal-retentive" and the derived informal term "anal". In addition to nerve endings, pleasure from anal intercourse may be aided by the close proximity between the anus and the prostate for males, vagina, clitoral legs and anal area for females; this is because of indirect stimulation of the vagina or clitoral legs. For a male insertive partner, the tightness of the anus can be a source of pleasure via the tactile pressure on the penis. Pleasure from the anus can be achieved through anal masturbation, facesitting and other penetrative and non-penetrative acts.
Anal stretching or fisting is pleasurable for some, but it poses a more serious threat of damage due to the deliberate stretching of the anal and rectal tissues. Lubricant and condoms are regarded as a necessity while performing anal sex as well as a slow and cautious penetration. Anal intercourse is sometimes referred to as sodomy or buggery, is considered taboo in a number of legal systems, it has been, in some jurisdictions continues to be, a crime carrying severe punishment. To prevent diseases of the anus and to promote general hygiene, humans clean the exterior of the anus after emptying the bowels. A rinse with water from a bidet or a wipe with toilet paper is used for this purpose, though anal cleansing practices vary between cultures. Shaving, depilatory, or Brazilian waxing can clear the perineum of hair. Anal bleaching is a process in which the anus and perineum, which may darken after puberty depending on individual genetics, is lig
Alvinolagnia or belly fetish or stomach fetish is a partialism in which an individual is sexually attracted to the stomach or belly. Anthropologists and behaviorists have discovered substantial evidence that the waist-hip ratio is a significant measure for female attractiveness, Some find a slender muscular stomach with a defined V-zone to be a turn-on; some fetishists get a turn-on from rubbing their belly region. Some people wear accessories like belly chains, navel piercings, tattoos etc. to enhance the appearance of the belly. It can be a delicate heavy thick chain. Managing editor of digital of Canadian magazine Flare Rebecca Perrin stated in an article, "a woman's waist and hips are two of the most physically attractive body parts there are – emphasizing them shouldn't be considered a faux pas and should instead be encouraged." Celebrities like Beyoncé, Miley Cyrus etc. are known for flaunting their belly chains. Navel piercing and navel tattoos has become more common among young women.
The trend of piercing or tattooing the navel became popular in the 1990s. It is popular among middle-aged women; some belly chains attach to a navel piercing. Similar to navel piercings, hip piercings are popular among women to express a bold personality; some get stomach tattoos to attract attention of the onlookers, but these tattoos are more preferred by women than men. From tribal to flowers, the choices are innumerable; some women get these tattoos drawn on their lower backs and flaunt them in low-rise jeans, shorts or skirts. Sometimes, looser clothing such as scarves or skirts around the female waist and curves can be an incredible turn-on. Scarves wrapped around the waist are common among belly dancers. Alvinolagnia co-exists with navel fetishism. Belly fetish model Helena Strong stated, "People admire my belly; the only thing I expose is my belly. Most guys with belly fetishes get embarrassed if they see me naked." Some assume that alvinolagnia is a cause of the prevalent western fashion of female midriff exposure.
According to a study done by All-Bran with 2,000 women aged over 30s have found that 67 percent of them stating female celebrities are making it more acceptable for women to wear belly-baring clothes. In the Victorian era, a small waist was considered the main trait of a beautiful woman; the advent of bikinis in 1946, the cheerleading fashion of the 1970s and low-rise fashion started in the early 1990s have contributed to it. Midriff exposure became common in the culture of 20th-century music with many famous female pop stars appeared on and offstage and in music videos with their midriff exposed; some get attracted to women wearing bikini. The eastern art of belly dancing places the female midriff on center stage; the dance movements of the torso are considered to be seductive. The bare female midriff is considered erotic in India. Baring the midriff has always been a fashion in Indian women attire. Indian women have traditionally worn saris that bares the midriff South Indian women; the exposure of midriff in a sari is considered to be erotic.
The midriff is revealed in other traditional female attires like Ghagra choli. Belly chain known as kamarband in India when worn with low-rise saris and lehengas are considered sensuous. Most Indian women wear belly chains during weddings and other ceremonies as a show of culture and tradition. Nowadays, women have been pairing these chains with western outfits to draw attention to their figures. Men are intrigued by the demure floor-length attire and tantalising display of a bare midriff in the back. Indian actress Ileana D'Cruz had commented that there were shots where a big porcelain seashell was thrown on her belly and flowers decorated around her waist during the shoot of her debut film and stated that the belly and navel is supposed to be a mark of a woman's beauty in South Indian films and they believe that the waist line is the most attractive part. Indian Singer Chinmayi had tweeted for a fan's question on wearing saree during performances,"Groups of men...take photographs of my waist + side of my chest, circle it and upload it on soft porn websites."
"I get messages on how they're masturbating to it,"Some Indian women too tend to get aroused on getting pinched on their midriff bared by the sari. This scenario was depicted in an advertising campaign for a leading constructions company group in India. With the tagline "Everything you love, is in arm's reach", it featured a man at office extending his arm out to pinch his wife's midriff at home, with her expressing joy by smiling and biting her lower lip, it was featured as a full page advertisement in Dec 2013 Chennai issue of the Times of India. Abdominal obesity Belly dance Midriff Navel Navel fetishism Navel in popular culture Waist Waist-hip ratio