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89-400: In male human anatomy , the foreskin , also known as the prepuce ( / ˈ p r iː p juː s / ), is the double-layered fold of skin , mucosal and muscular tissue at the distal end of the human penis that covers the glans and the urinary meatus . The foreskin is attached to the glans by an elastic band of tissue, known as the frenulum . The outer skin of the foreskin meets with

178-456: A peripheral neuropathy involving peripheral nerves of the somatosensory system. This may present as numbness or paresthesia . Haptic technology can provide touch sensation in virtual and real environments. In the field of speech therapy , tactile feedback can be used to treat speech disorders . Affectionate touch is present in everyday life and can take multiple forms. These actions, however, seem to carry specific functions even though

267-495: A sexual system called androdioecy . They can also coexist with females and hermaphrodites, a sexual system called trioecy . The sex of a particular organism may be determined by a number of factors. These may be genetic or environmental, or may naturally change during the course of an organism's life. Although most species have only two sexes (either male or female), hermaphroditic animals, such as worms , have both male and female reproductive organs. Not all species share

356-455: A common sex-determination system . In most animals , including humans , sex is determined genetically ; however, species such as Cymothoa exigua change sex depending on the number of females present in the vicinity. Most mammals , including humans , are genetically determined as such by the XY sex-determination system where males have XY (as opposed to XX in females) sex chromosomes . It

445-454: A few species. Anisogamy appears to have evolved multiple times from isogamy; for example, female Volvocales (a type of green algae) evolved from the plus mating type. Although sexual evolution emerged at least 1.2 billion years ago, the lack of anisogamous fossil records make it hard to pinpoint when males evolved. One theory suggests male evolved from the dominant mating type (called mating type minus). A common symbol used to represent

534-495: A group of nerve endings involved in fine-touch sensitivity. Compared to other hairless skin areas on the body, the Meissner's index was highest in the finger tip (0.96) and lowest in the foreskin (0.28) which suggested that the foreskin has the least sensitive hairless tissue of the body. The foreskin helps to provide sufficient skin during an erection. In infants, it protects the glans from ammonia and feces in diapers, which reduces

623-593: A similar procedure is performed to relieve a tight foreskin without resorting to circumcision. Foreskins obtained from circumcision procedures are frequently used by biochemical and micro-anatomical researchers to study the structure and proteins of human skin. In particular, foreskins obtained from newborns have been found to be useful in the manufacturing of more human skin. Foreskins of babies are also used for skin graft tissue, and for β-interferon -based drugs. Foreskin-derived fibroblasts have been used in biomedical research, and cosmetic applications. The foreskin

712-486: A small receptive field (extremely detailed information), they are used in areas like fingertips the most; they are not covered (shelled) and thus respond to pressures over long periods. Tactile corpuscles react to moderate vibration (10–50 Hz) and light touch. They are located in the dermal papillae ; due to their reactivity, they are primarily located in fingertips and lips. They respond in quick action potentials , unlike Merkel nerve endings. They are responsible for

801-458: A tight foreskin becomes trapped behind the glans and swells as a restrictive ring. This can cut off the blood supply, resulting in ischemia of the glans penis. Lichen sclerosus is a chronic, inflammatory skin condition that most commonly occurs in adult women, although it may also be seen in men and children. Topical clobetasol propionate and mometasone furoate were proven effective in treating genital lichen sclerosus. Some birth defects of

890-418: A way of displaying traits that signify their fitness . Sexual selection is believed to be the driving force behind the development of these characteristics. Differences in physical size and the ability to fulfill the requirements of sexual selection have contributed significantly to the outcome of secondary sex characteristics in each species. In many species, males differ from females in more ways than just

979-430: Is a type of sensory information that elicits an emotional reaction and is usually social in nature, such as a physical human touch. This type of information is actually coded differently than other sensory information. Intensity of affective touch is still encoded in the primary somatosensory cortex and is processed in a similar way to emotions invoked by sight and sound, as exemplified by the increase of adrenaline caused by

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1068-507: Is a vestigial structure devoid of function... However, it seems to be no accident that during the years when the child is incontinent the glans is completely clothed by the prepuce, for, deprived of this protection, the glans becomes susceptible to injury from contact with sodden clothes or napkin". During the physical act of sex, the foreskin reduces friction, which can reduce the need for additional sources of lubrication. The College of Physicians and Surgeons of British Columbia has written that

1157-462: Is also possible in a variety of species, including humans, to be XX male or have other karyotypes . During reproduction , a male can give either an X sperm or a Y sperm, while a female can only give an X egg. A Y sperm and an X egg produce a male, while an X sperm and an X egg produce a female . The part of the Y-chromosome which is responsible for maleness is the sex-determining region of

1246-431: Is anatomically homologous to the clitoral hood in females. In some cases, the foreskin may become subject to a pathological condition. The outside of the foreskin is a continuation of the shaft skin of the penis and is covered by a keratinized stratified squamous epithelium . The inner foreskin is a continuation of the epithelium that covers the glans and is made up of glabrous squamous mucous membrane , like

1335-475: Is attached to the glans by the frenulum , a highly vascularized tissue of the penis. The World Health Organization states that "the frenulum forms the interface between the outer and inner foreskin layers, and when the penis is not erect, it tightens to narrow the foreskin opening. The human foreskin is a laminar structure made up of outer skin , mucosal epithelium , lamina propia , dartos fascia and dermis . The superficial dartos fascia, formerly called

1424-453: Is better among adults with smaller index fingertips; this effect of finger size has been shown to underlie the better passive tactile spatial acuity of women, on average, compared to men. The density of tactile corpuscles , a type of mechanoreceptor that detects low-frequency vibrations, is greater in smaller fingers; the same may hold for Merkel cells , which detect the static indentations important for fine spatial acuity. Among children of

1513-456: Is complete. Towards the end of the second trimester , the glans and the prepuce have completely fused together by the preputial, sometimes referred to as balanopreputial lamina. At birth, this shared membrane is physiologically adherent to the glans preventing retraction in infancy and early childhood. The phenomenon of non-retractile foreskin in children naturally starts to resolve in varying ages; in childhood, preadolescence or puberty. During

1602-414: Is fused to the glans at birth and is generally not retractable in infancy and early childhood. Inability to retract the foreskin in childhood should not be considered a problem unless there are other symptoms. Retraction of the foreskin is not recommended until it loosens from the glans before or during puberty. In adults, it is typically retractable over the glans, given normal development. The male prepuce

1691-472: Is important amongst some animals. Usually, tactile contact between two animals occurs through stroking, licking, or grooming. These behaviours are essential for the individual's social healthcare, as in the hypothalamus they induce the release of oxytocin, a hormone that decreases stress and anxiety and increases social bonding between animals. More precisely, the consistency of oxytocin neuron activation in rats stroked by humans has been observed, especially in

1780-577: Is in the parietal lobe and its cortex is the primary somatosensory cortex ( Brodmann areas 3, 2 and 1 ) collectively referred to as S1. BA3 receives the densest projections from the thalamus . BA3a is involved with the sense of relative position of neighboring body parts and amount of effort being used during movement. BA3b is responsible for distributing somatosensory information, it projects texture information to BA1 and shape and size information to BA2. Region S2 ( secondary somatosensory cortex ) divides into Area S2 and parietal ventral area. Area S2

1869-412: Is initiated at around eleven weeks or earlier and continues up to eighteen weeks. Historically, the theories regarding the stages of preputial development during gestation fall into two main ideas. The earliest report by Schweigger-Seidel (1866) and later Hunter (1935) suggested the formation of the prepuce out of dorsal skin and its progressive distal extension to completely cover and eventually fuse with

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1958-494: Is involved in numerous functions. The somatosensory system is spread through all major parts of the vertebrate body. It consists both of sensory receptors and sensory neurons in the periphery (skin, muscle and organs for example), to deeper neurons within the central nervous system . All afferent touch/vibration information ascends the spinal cord via the dorsal column-medial lemniscus pathway via gracilis (T7 and below) or cuneatus (T6 and above). Cuneatus sends signals to

2047-508: Is involved with specific touch perception and is thus integrally linked with the amygdala and hippocampus to encode and reinforce memories. Parietal ventral area is the somatosensory relay to the premotor cortex and somatosensory memory hub, BA5. BA5 is the topographically organized somato memory field and association area. BA1 processes texture info while BA2 processes size and shape information. Area S2 processes light touch, pain, visceral sensation, and tactile attention. S1 processes

2136-405: Is part of the human phylogenetic heritage and is present in the vast majority of mammals. Non-human primates , such as the chimpanzees , have prepuces that partially or completely cover the glans penis. In primates, the foreskin is present in the genitalia of both sexes and likely has been present for millions of years of evolution. The World Health Organization (WHO) stated in 2007 that there

2225-412: Is sensitive to temperature and reacts to temperature changes by expanding and contracting. The fascia is only loosely connected with the underlying tissue, so that it provides the mobility and elasticity of the penile skin. Langerhans cells are immature dendritic cells that are found in all areas of the penile epithelium, but are most superficial in the inner surface of the foreskin. As a continuation of

2314-409: Is the pathway responsible for the sending of fine touch information to the cerebral cortex of the brain. Crude touch (non-discriminating) is a sensory modality that allows the subject to sense that something has touched them, without being able to localize where they were touched (contrasting "fine touch"). Its fibres are carried in the spinothalamic tract , unlike the fine touch, which is carried in

2403-449: Is true for many species of birds where the male displays more vibrant colors than the female, making them more noticeable to potential mates. These characteristics have evolved over time as a result of sexual selection, as males who exhibited these traits were more successful in attracting mates and passing on their genes. Somatosensory system Mechanosensory information includes that of light touch, vibration, pressure and tension in

2492-411: The epidermis that separates from the penis creating a raised fold, known as the preputial fold. On the underside of this structure forms the preputial lamina, which expands dorsolaterally over the base of the developing glans. At thirteen weeks, the prepuce has not yet extended to the distal tip of the glans covering only a part of its surface. By sixteen weeks, the bilateral preputial folds cover most of

2581-411: The epithelium of the glans. Glenister (1956) expanded the theory suggesting that the preputial fold results as an ingrowth of the cellular lamina , which rolls outwards over the glans, but with the resultant preputial lamina also expanding backwards to form an ingrowing fold at the coronal sulcus. By eleven and twelve weeks of gestation, the process of preputial formation is evident as a thickening of

2670-483: The gamete (sex cell) known as sperm , which fuses with the larger female gamete, or ovum , in the process of fertilisation . A male organism cannot reproduce sexually without access to at least one ovum from a female, but some organisms can reproduce both sexually and 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 . In humans,

2759-433: The peripenic muscle , is one of the two sheaths of smooth muscle tissue found below the penile skin, along with the underlying Buck's fascia or deep fascia of the penis . The dartos fascia extents within the skin of the prepuce and contains an abuncance of elastic fibers . These fibers form a whorl at the tip of the foreskin, known as the preputial orifice, which is narrow during infancy and childhood. The dartos fascia

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2848-653: The Y-chromosome, the SRY . The SRY activates Sox9 , which forms feedforward loops with FGF9 and PGD 2 in the gonads , allowing the levels of these genes to stay high enough in order to cause male development; for example, Fgf9 is responsible for development of the spermatic cords and the multiplication of Sertoli cells , both of which are crucial to male sexual development. The ZW sex-determination system , where males have ZZ (as opposed to ZW in females) sex chromosomes, may be found in birds and some insects (mostly butterflies and moths ) and other organisms. Members of

2937-509: The ability to read Braille and feel gentle stimuli. Pacinian corpuscles determine gross touch and distinguish rough and soft substances. They react in quick action potentials, especially to vibrations around 250 Hz (even up to centimeters away). They are the most sensitive to vibrations and have large receptor fields. Pacinian corpuscles react only to sudden stimuli so pressures like clothes that are always compressing their shape are quickly ignored. They have also been implicated in detecting

3026-436: The body, creating a map or sensory homunculus . Tactile signing is a common means of communication used by people with deafblindness . It is based on a sign language or another system of manual communication. Humans can communicate specific emotions through touch alone including anger, fear, disgust, love, gratitude, and sympathy via touch at much-better-than-chance levels. The two different types of mechanoreceptor in

3115-399: The brain for conscious perception. Somatosensory information from the face and head enter the brain via cranial nerves such as the trigeminal nerve . The neural pathways that go to the brain are structured such that information about the location of the physical stimulus is preserved. In this way, neighboring neurons in the somatosensory cortex represent nearby locations on the skin or in

3204-408: The caudal paraventricular nucleus. It was found that this affiliative relationship induced by tactile contact is common no matter the relationship between the two individuals (mother-infant, male-female, human-animal). It has also been discovered that the level of oxytocin release through this behaviour correlates with the time course of social interaction as longer stroking induced a greater release of

3293-551: The cochlear nucleus indirectly via spinal grey matter, this info is used in determining if a perceived sound is just villi noise/irritation. All fibers cross (left becomes right) in the medulla. A somatosensory pathway will typically have three neurons: first-order, second-order, and third-order. Photoreceptors, similar to those found in the retina of the eye , detect potentially damaging ultraviolet radiation ( ultraviolet A specifically), inducing increased production of melanin by melanocytes . Thus tanning potentially offers

3382-630: The context of gender , such as for gender role or gender identity of a man or boy . For example, according to Merriam-Webster, "male" can refer to "having a gender identity that is the opposite of female". According to the Cambridge Dictionary, "male" can mean "belonging or relating to men". Male can also refer to a shape of connectors . Species that are divided into females and males are classified as gonochoric in animals, as dioecious in seed plants and as dioicous in cryptogams . Males can coexist with hermaphrodites,

3471-425: The dominant individual in a group becomes female while the other ones are male. In many arthropods , sex is determined by infection with parasitic , endosymbiotic bacteria of the genus Wolbachia . The bacterium can only be transmitted via infected ova, and the presence of the obligate endoparasite may be required for female sexual viability. Male animals have evolved to use secondary sex characteristics as

3560-420: The dorsal column. As fine touch normally works in parallel to crude touch, a person will be able to localize touch until fibres carrying fine touch (in the dorsal column–medial lemniscus pathway) have been disrupted. Then the subject will feel the touch, but be unable to identify where they were touched. The somatosensory cortex encodes incoming sensory information from receptors all over the body. Affective touch

3649-444: The environment uses special sensory receptors in the skin called cutaneous receptors . They include mechanoreceptors such as tactile corpuscles that relay information about pressure and vibration; nociceptors, and thermoreceptors for temperature perception. Stimulation of the receptors activate peripheral sensory neurons that convey signals to the spinal cord that may drive a responsive reflex , and may also be conveyed to

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3738-476: The evaluation of risks that occur during conducting such behaviours in the wild life, and further research is required to unveil the connection between tactile caring and fitness level. Studies show a correlation between touching a soft or hard object and how a person thinks or even makes decisions. Further, between the firmness of a touch and the evoking of gender stereotyping. Tactile memories as part of haptic memory , are organized somatotopically , following

3827-468: The evolutionary benefit from such a wide range of behaviours is not entirely understood. Researchers investigated the expression patterns and characteristics of 8 different affectionate touch actions - embracing, holding, kissing, leaning, petting, squeezing, stroking, and tickling - in a self-report study. It was found that the affectionate touch has distinct target areas on the body, different associated affect, comfort-value, and expression frequency based on

3916-400: The female and male gamete-producing organisms and structures but also the structures of the sporophytes that give rise to male and female plants. The evolution of anisogamy led to the evolution of male and female function. Before the evolution of anisogamy, mating types in a species were isogamous : the same size and both could move, catalogued only as "+" or "-" types. In anisogamy,

4005-519: The first years of life, the inner foreskin is fused to the glans making them hard to manually separate. At that time, forced retraction can cause pain or microtearing and is thus not recommended. The two surfaces may begin to separate from early childhood, but complete separation and retraction is a process that normally occurs over time. The phenomenon of non retractile or tight foreskin in childhood, sometimes referred to as physiologic phimosis, may completely resolve before, during or even after puberty. When

4094-409: The foreskin can harbor micro-organisms that may increase the risk of urinary tract infections in some infants and contribute to the transmission of some sexually transmitted infections in adults. In some cases of recurrent pathologies, excessive soap washing may irritate the mucosa, therefore washing of the area should be done gently. Frenulum breve is a frenulum that is insufficiently long to allow

4183-437: The foreskin can occur; all of them are rare. In aposthia there is no foreskin at birth, in micropathia the foreskin does not cover the glans, and in macroposthia, also called and congenital megaprepuce, the foreskin extends well past the end of the glans. It has been found that larger foreskins place men who are not circumcised at an increased risk of HIV infection most likely due to the larger surface area of inner foreskin and

4272-692: The foreskin is "composed of an outer skin and an inner mucosa that is rich in specialized sensory nerve endings and erogenous tissue". In the March 2017 publication of the Global Health Journal: Science and Practice , Morris and Krieger wrote, "The variability in foreskin size is consistent with the foreskin being a vestigial structure". The foreskin can be involved in balanitis , phimosis , sexually transmitted infection and penile cancer . The American Academy of Pediatricians' now expired 2012 technical report on circumcision found that

4361-528: The foreskin is suggested for all adults, particularly for those with a long or 'redundant' foreskin. Some males, according to Xianze (2012), may be reluctant for their glans to be exposed because of discomfort when it chafes against clothing, although the discomfort on the glans was reported to diminish within one week of continuous exposure. Guochang (2010) states that for those whose foreskins are too tight to retract or have some adhesions, forcible retraction should be avoided since it may cause injury. The foreskin

4450-432: The foreskin remains covering all or some of the glans until retracted manually or by sexual activity . The foreskin can be classified as long, when the preputial orifice extents beyond the glans, medium, when the preputial orifice is located around the meatus, and short, when most of the glans is exposed. The variation of long foreskin was regarded by Chengzu (2011) as 'prepuce redundant'. Frequent retraction and washing under

4539-468: The foreskin starts to become retractile, a pediatrician can recommend careful retraction at home and rinsing with water during bath. Mild soap may be used, but can be avoided, if it causes irritation. If full retraction is hard to achieve, the child may only wash the exposed area of the glans. Since there is no specific age when non-retractile foreskin begins to resolve, the time of foreskin retraction can vary considerably among children. During puberty , as

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4628-407: The foreskin to fully retract, which may lead to discomfort during intercourse. Phimosis is a condition where the foreskin of an adult cannot be retracted properly. Phimosis can be treated by using topical steroid ointments and using lubricants during sex; for severe cases circumcision may be necessary. Posthitis is an inflammation of the foreskin. A condition called paraphimosis may occur if

4717-476: The glans and the ventral sides of the prepuce fuse in the midline. The penile raphe , the continuation of the perineal raphe in human males, occurs on the ventral side of the penis as a manifestation of the fusion of the urethral and preputial folds. The dorsal nerve of the penis, which is present as early as nine weeks of gestation, completely expands through branches to the distal end of the glans and prepuce by sixteen weeks. At nineteen weeks, foreskin development

4806-467: The high concentration of Langerhans cells . Circumcision is the removal of the foreskin, either partially or completely. It is most commonly performed as an elective procedure for prophylactic , cultural , or religious reasons. Circumcision may also be performed on children or adults to treat phimosis, balanitis, and other pathologies. The ethics of circumcision in children is a source of controversy . Some men use weights or other devices to stretch

4895-479: The historical evidence favours "the conclusion of the French classical scholar Claude de Saumaise (Salmasius, 1588–1683)" that it is derived from θρ , the contraction of a Greek name for the planet Mars, which is Thouros . Borrowed from Old French masle , from Latin masculus ("masculine, male, worthy of a man"), diminutive of mās ("male person or animal, male"). In humans, the word male can be used in

4984-402: The hormone. The importance of somatosensory stimulation in social animals such as primates has also been observed. Grooming is part of the social interaction primates exert on their conspecifics. This interaction is required between individuals to maintain the affiliative relationship within the group, avoid internal conflict and increase group bonding. However, such social interaction requires

5073-408: The human shaft skin, the prepuce receives somatosensory innervation from the bilateral dorsal nerve of the penis and branches of the perineal nerve , and autonomic innervation from the pelvic plexus . The somatosensory receptors that are found in the prepuce are both nociceptors and mechanoreceptors , with a predominace of Meissner's corpuscles . Blood supply to the prepuce is provided by

5162-400: The incidence of meatal stenosis . And the foreskin helps prevent the glans from getting abrasions and trauma throughout life. In modern times, there is controversy regarding whether the foreskin is a vital or vestigial structure . In 1949, British physician Douglas Gairdner noted that the foreskin plays an important protective role in newborns. He wrote, "It is often stated that the prepuce

5251-445: The inner preputial mucosa at the area of the mucocutaneous junction . The foreskin is mobile, fairly stretchable and sustains the glans in a moist environment. Except for humans, a similar structure known as a penile sheath appears in the male sexual organs of all primates and the vast majority of mammals . In humans, foreskin length varies widely and coverage of the glans in a flaccid and erect state can also vary. The foreskin

5340-529: The insect order Hymenoptera , such as ants and bees , are often determined by haplodiploidy , where most males are haploid and females and some sterile males are diploid . However, fertile diploid males may still appear in some species, such as Cataglyphis cursor . In some species of reptiles, such as alligators , sex is determined by the temperature at which the egg is incubated. Other species, such as some snails , practice sex change: adults start out male, then become female. In tropical clown fish ,

5429-419: The inside of the eyelid or the mouth . The mucosal aspect of the prepuce has a great capacity for self-repair. The area of the outer foreskin measures 7–100 cm, and the inner foreskin measures 18–68 cm. The mucocutaneous zone occurs where the outer and inner foreskin meet. The foreskin is free to move after it separates from the glans, which usually occurs before or during puberty . The inner foreskin

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5518-428: The location of objects which are sensed by the visual system (which provides confirmation of the place of those objects relative to the body), as input to the mechanical reflexes of the body. Fine touch (or discriminative touch) is a sensory modality that allows a subject to sense and localize touch. The form of touch where localization is not possible is known as crude touch. The dorsal column–medial lemniscus pathway

5607-509: The location of touch sensations on handheld tools. Bulbous corpuscles react slowly and respond to sustained skin stretch. They are responsible for the feeling of object slippage and play a major role in the kinesthetic sense and control of finger position and movement. Merkel and bulbous cells - slow-response - are myelinated ; the rest - fast-response - are not. All of these receptors are activated upon pressures that distort their shape causing an action potential. The postcentral gyrus

5696-434: The male begins to sexually mature , foreskin retractability gradually increases allowing more comfortable exposure of the glans when needed. Gentle washing under the foreskin during shower and maintaining good genital hygiene is sufficient to prevent smegma buildup. Smegma is an oily secretion in the genitals of both sexes that maintains the moist texture of the mucosal surfaces and prevents friction. In boys, it helps resolve

5785-522: The male sex is the Mars symbol ♂, a circle with an arrow pointing northeast . The Unicode code-point is: The symbol is identical to the planetary symbol of Mars . It was first used to denote sex by Carl Linnaeus in 1751. The symbol is sometimes seen as a stylized representation of the shield and spear of the Roman god Mars . According to William T. Stearn , however, this derivation is "fanciful" and all

5874-494: The mating type is called a gamete. The male gamete is smaller than the female gamete, and usually mobile. Anisogamy remains poorly understood, as there is no fossil record of its emergence. Numerous theories exist as to why anisogamy emerged. Many share a common thread, in that larger female gametes are more likely to survive, and that smaller male gametes are more likely to find other gametes because they can travel faster. Current models often fail to account for why isogamy remains in

5963-421: The molecular level) to anisogamous species with gametes of male and female types to oogamous species in which the female gamete is very much larger than the male and has no ability to move. There is a good argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for sexual reproduction . Accordingly, sex is defined across species by

6052-466: The most rigorous being the grating orientation task. In this task subjects identify the orientation of a grooved surface presented in two different orientations, which can be applied manually or with automated equipment. Many studies have shown a decline in passive tactile spatial acuity with age; the reasons for this decline are unknown, but may include loss of tactile receptors during normal aging. Remarkably, index finger passive tactile spatial acuity

6141-424: The natural adhension of the glans and inner prepuce. By the end of puberty, most boys have a fully retractable foreskin. In children, the foreskin usually covers the glans completely but in adults it may not. During erection , the degree of automatic foreskin retraction varies considerably; in some adults, when the foreskin is longer than the erect penis, it will not spontaneously retract upon erection. In this case,

6230-416: The organization of the somatosensory cortex. A variety of studies have measured and investigated the causes for differences between individuals in the sense of fine touch. One well-studied area is passive tactile spatial acuity, the ability to resolve the fine spatial details of an object pressed against the stationary skin. A variety of methods have been used to measure passive tactile spatial acuity, perhaps

6319-483: The penis that drain the rest of the penile shaft. The penis develops from a primordial phallic structure that forms in the embryo during the early weeks of pregnancy, known as the genital tubercle . Initially undifferentiated, the tubercle develops into a penis depending on the exposure to male hormones secreted by the testicles . The differentiation of the external sexual organs will be evident between twelve and sixteen weeks of gestation . Preputial development

6408-418: The physical sensation to its related conceptual processing. Indeed, it was found that different physical properties - weight, texture, and hardness - of a touched object can influence social judgement and decision-making. For example, participants described a passage of a social interaction to be harsher when they touched a hard wooden block instead of a soft blanket prior to the task. Building on these findings,

6497-509: The prefrontal cortex is highly correlated with pleasantness scores of an affective touch. Inhibitory transcranial magnetic stimulation (TMS) of the primary somatosensory cortex inhibits the perception of affective touch intensity, but not affective touch pleasantness. Therefore, the S1 is not directly involved in processing socially affective touch pleasantness, but still plays a role in discriminating touch location and intensity. Tactile interaction

6586-400: The preputial artery, a division of the axial and dorsal artery of the penis . The axial and dorsal arteries that run within the penile skin unite through perforating branches and give off the preputial arteries before they reach the corona of the glans . The preputial vein, an extension of the superficial dorsal vein, receives blood from the prepuce and connects to the larger dorsal veins of

6675-572: The production of sperm. For example, in some insects and fish, the male is smaller than the female. In seed plants, the sporophyte sex organ of a single organism includes both the male and female parts. In mammals, including humans, males are typically larger than females. This is often attributed to the need for male mammals to be physically stronger and more competitive in order to win mating opportunities. In humans specifically, males have more body hair and muscle mass than females. Birds often exhibit colorful plumage that attracts females. This

6764-420: The proprioceptors in the skin, muscles, and joints. The receptor for the sense of balance resides in the vestibular system in the ear (for the three-dimensional orientation of the head, and by inference, the rest of the body). Balance is also mediated by the kinesthetic reflex fed by proprioception (which senses the relative location of the rest of the body to the head). In addition, proprioception estimates

6853-505: The recognition of every member in the group. As such, it has been observed that the size of the neocortex is positively correlated with the size of the group, reflecting a limit to the number of recognizable members amongst which grooming can occur. Furthermore, the time course of grooming is related to vulnerability due to predation to which animals are exposed to whilst performing such social interaction. The relationship between tactile interaction, stress reduction and social bonding depends on

6942-411: The remaining info (crude touch, pain, temperature). BA7 integrates visual and proprioceptive info to locate objects in space. The insular cortex (insula) plays a role in the sense of bodily-ownership, bodily self-awareness, and perception. Insula also plays a role in conveying info about sensual touch, pain, temperature, itch, and local oxygen status. Insula is a highly connected relay and thus

7031-531: The same age, those with smaller fingers also tend to have better tactile acuity. Many studies have shown that passive tactile spatial acuity is enhanced among blind individuals compared to sighted individuals of the same age, possibly because of cross modal plasticity in the cerebral cortex of blind individuals. Perhaps also due to cortical plasticity, individuals who have been blind since birth reportedly consolidate tactile information more rapidly than sighted people. A somatosensory deficiency may be caused by

7120-504: The skin are termed low-threshold mechanoreceptors , and high threshold mechanoreceptors . The four mechanoreceptors in glabrous skin are low-threshold that respond to harmless stimuli. They are innervated by four different afferent fibers. High-threshold mechanoreceptors, respond to harmful stimuli . Merkel cell nerve endings are found in the basal epidermis and hair follicles ; they react to low vibrations (5–15  Hz ) and deep static touch such as shapes and edges. Due to having

7209-402: The skin of the penis to regrow a foreskin; the resulting tissue does cover the glans but does not fully replicate the features of a foreskin. Other cultural or aesethetic practices include genital piercings involving the foreskin and slitting the foreskin . Preputioplasty is the most common foreskin reconstruction technique, most often done when a boy is born with a foreskin that is too small;

7298-409: The skin rapid protection from DNA damage and sunburn caused by ultraviolet radiation (DNA damage caused by ultraviolet B ). However, whether this offers protection is debatable, because the amount of melanin released by this process is modest in comparison to the amounts released in response to DNA damage caused by ultraviolet B radiation. The tactile feedback from proprioception is derived from

7387-470: The skin. Much of this information belongs to the sense of touch which is a general somatic sense in contrast to the special senses of sight , smell , taste , hearing and balance . Nociceptory information is that received from pain and temperature that is deemed as harmful (noxious). Thermoreceptors relay temperature information in normal circumstances. Nociceptors are specialised receptors for signals of pain. The sense of touch in perceiving

7476-419: The social touch of a loved one, as opposed to the physical inability to touch someone you do not love. Meanwhile, the feeling of pleasantness associated with affective touch activates the anterior cingulate cortex more than the primary somatosensory cortex. Functional magnetic resonance imaging (fMRI) data shows that increased blood-oxygen-level contrast (BOLD) signal in the anterior cingulate cortex as well as

7565-422: The type of gametes produced (i.e.: spermatozoa vs. ova) and differences between males and females in one lineage are not always predictive of differences in another. Male/female dimorphism between organisms or reproductive organs of different sexes is not limited to animals; male gametes are produced by chytrids , diatoms and land plants , among others. In land plants, female and male designate not only

7654-466: The type of touch action that is performed. Besides the rather obvious sensory consequences of touch, it can also affect higher-level aspects of cognition such as social judgements and decision-making. This effect might arise due to a physical-to-mental scaffolding process in early development, whereby sensorimotor experiences are linked to the emergence of conceptual knowledge. Such links might be maintained throughout life, and so touching an object may cue

7743-504: The word male can also be used to refer to gender , in the social sense of gender role or gender identity . The use of "male" in regard to sex and gender has been subject to discussion . The existence of separate sexes has evolved independently at different times and in different lineages , an example of convergent evolution . The repeated pattern is sexual reproduction in isogamous species with two or more mating types with gametes of identical form and behavior (but different at

7832-529: Was "debate about the role of the foreskin, with possible functions including keeping the glans moist, protecting the developing penis in utero, or enhancing sexual pleasure due to the presence of nerve receptors". In 2009, the World Health Organization called it a "myth" that circumcision has an effect on sexual pleasure. The view is echoed by other major medical organizations . The foreskin contains Meissner's corpuscles , which are one of

7921-493: Was considered a sign of beauty , civility , and masculinity throughout the Greco-Roman world . In ancient Greece , foreskins were valued, especially those that were longer. The earliest known illustrative depiction of the foreskin dates back to Egyptian kingdoms . The foreskin has also been depicted in art from different historical ages: Male Male ( symbol : ♂ ) is the sex of an organism that produces

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