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111-429: The autonomic nervous system is responsible for regulating the body's unconscious actions. The parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed-and-breed" activities that occur when the body is at rest, especially after eating, including sexual arousal , salivation , lacrimation (tears), urination , digestion , and defecation . Its action is described as being complementary to that of

222-439: A mating season , and both sexes are potentially capable of sexual arousal throughout the year. Sexual arousal for most people is a positive experience and an aspect of their sexuality, and is often sought. A person can normally control how they will respond to arousal. They will normally know what things or situations are potentially stimulating, and may at their leisure decide to either create or avoid these situations. Similarly,

333-409: A persistent genital arousal disorder , which is a spontaneous, persistent, and uncontrollable arousal, and the physiological changes associated with arousal. Sexual arousal causes various physical responses, most significantly in the sex organs (genital organs). Sexual arousal for a man is usually indicated by the swelling and erection of the penis when blood fills the corpus cavernosum . This

444-435: A refractory period characterized by loss of their erection, a subsidence in any sex flush, less interest in sexual activity, and a feeling of relaxation that can be attributed to the neurohormones oxytocin and prolactin . The intensity and duration of the refractory period can be very short in a highly aroused young man in a highly arousing situation, perhaps without even a noticeable loss of erection. It can be as long as

555-462: A romantic setting, music or other soothing situation. Sexual arousal can come from porn or other sexual material. The potential stimuli for sexual arousal vary from person to person, and from one time to another, as does the level of arousal. Stimuli can be classified according to the sense involved: somatosensory (touch), visual, and olfactory (scent). Auditory stimuli are also possible, though they are generally considered secondary in role to

666-672: A conscious level of awareness, while an internal cognition can elicit the same effects indirectly, through the conscious representation of a sexual image. In the case of inhibition, sexual behavior can be active or conscious (e.g., choosing not to have sex) or it can be passive or unconscious (e.g., being unable to have sex due to fear). Toates emphasizes the importance considering cognitive representations in addition to external stimuli; he suggests that mental representations of incentives are interchangeable with excitatory external stimuli for eliciting sexual arousal and motivation. This model created by John Bancroft and Erick Janssen, previously at

777-420: A crucial role in heart rate regulation by modulating the response of sinoatrial node; vagal tone can be quantified by investigating heart rate modulation induced by vagal tone changes. As a general consideration, increased vagal tone (and thus vagal action) is associated with a diminished and more variable heart rate. The main mechanism by which the parasympathetic nervous system acts on vascular and cardiac control

888-462: A few hours or days in middle-aged and older men. The beginnings of sexual arousal in a woman's body is usually marked by vaginal lubrication (wetness; though this can occur without arousal due to infection or cervical mucus production around ovulation), swelling and engorgement of the vulva , and internal lengthening and enlargement of the vagina . There have been studies to find the degree of correlation between these physiological responses and

999-510: A greater impact on women's sexual functioning than their menopausal status. It is therefore seen as important always to understand the "context of women's lives" when studying their sexuality. Reduced estrogen levels may be associated with increased vaginal dryness and less clitoral erection when aroused, but are not directly related to other aspects of sexual interest or arousal. In older women, decreased pelvic muscle tone may mean that it takes longer for arousal to lead to orgasm, may diminish

1110-473: A healthy heart, the main pacemaker is a collection of cells on the border of the atria and vena cava called the sinoatrial node. Heart cells have the ability to generate electrical activity independent of external stimulation. As a result, the cells of the node spontaneously generate electrical activity that is subsequently conducted throughout the heart, resulting in a regular heart rate. In absence of any external stimuli, sinoatrial pacing contributes to maintain

1221-400: A laboratory setting. This field of research looks at physical sexual responses in addition to mental and emotional experiences of sexual arousal. Various hypotheses and theories have been propounded in order to establish the biological bases for sexual arousal in humans. Ivan Tarkhanov showed, in experiments on cutting and artificial emptying of the seminal vesicles , that the latter played

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1332-483: A lack of spontaneous desire should not be taken as an indication of female sexual dysfunction ; many women experience sexual arousal and responsive desire simultaneously when they are engaged in sexual activity. Frederick Toates presented a model of sexual motivation, arousal, and behavior in 2009 that combines the principles of incentive-motivation theory and hierarchical control of behavior . The basic incentive-motivation model of sex suggests that incentive cues in

1443-409: A male erection can occur during sleep ( nocturnal penile tumescence ) without conscious sexual arousal or due to mechanical stimulation (e.g., rubbing against the bed sheet) alone. A young man—or one with a strong libido—may experience enough sexual arousal for an erection to result from a passing thought, or just the sight of a passerby. Once erect, his penis may gain enough stimulation from contact with

1554-460: A measure to protect the internal organs of the vagina. Geniculate ganglion The geniculate ganglion (from Latin genu , for "knee" ) is a bilaterally paired special sense ganglion of the intermediate nerve component of the facial nerve (CN VII) . It is situated within facial canal of the head . It contains cell bodies of first-order unipolar sensory neurons which convey gustatory (taste) afferents from taste receptors of

1665-480: A medical or physical condition. The lack of sexual arousal may be due to a general lack of sexual desire or due to a lack of sexual desire for the current partner. A person may always have had no or low sexual desire or the lack of desire may have been acquired during the person's life. On the other hand, a person may be hypersexual , which is a desire to engage in sexual activities considered abnormally high in relation to normal development or culture, or suffering from

1776-420: A model of the process of sexual arousal in 1984, in which he conceptualized human sexual response to be composed of three independent but generally sequential components . The first stage, aesthetic response, is an emotional reaction to noticing an attractive face or figure. This emotional reaction produces an increase in attention toward the object of attraction, typically involving head and eye movements toward

1887-442: A person's sexual partner will normally also know their partner's erotic stimuli and turn-offs. Some people feel embarrassed by sexual arousal and some are sexually inhibited . Some people do not feel aroused on every occasion that they are exposed to erotic stimuli, nor act in a sexual way on every arousal. A person can take an active part in a sexual activity without sexual arousal. These situations are considered normal, but depend on

1998-720: A rapid increase in testosterone in women who were not using hormonal contraception . In terms of brain activation, researchers have suggested that amygdala responses are not solely determined by level of self-reported sexual arousal; Hamann and colleagues found that women self-reported higher sexual arousal than men, but experienced lower levels of amygdala responses. During the late 1950s and early 1960s, William H. Masters and Virginia E. Johnson conducted multiple studies into human sexuality . In 1966, they published Human Sexual Response , detailing four stages of physiological changes in humans during sexual stimulation: excitement, plateau, orgasm, and resolution. Barry Singer presented

2109-429: A separate cranial nerve altogether) to connect with the facial nerve just distal (further out) to it surfacing the central nervous system. Just after the facial nerve geniculate ganglion (general sensory ganglion) in the temporal bone , the facial nerve gives off two separate parasympathetic nerves. The first is the greater petrosal nerve and the second is the chorda tympani . The greater petrosal nerve travels through

2220-432: A similar way to VPG, but measures changes in clitoral blood volume, rather than vaginal vasocongestion. Thermography provides a direct measure of genital sexual arousal by measuring changes in temperature associated with increased blood flow to the vulvar tissues. Similarly, labial thermistor clips measure changes in temperature associated with genital engorgement; this method directly measures changes in temperature of

2331-453: A small number of closely linked brain mechanisms and therefore not subject to significant multivariate effects, cannot be subject to such a large sex difference as that apparent in pletysmographic studies. These neurologists cite the existence of significant volunteering bias among men but not women in erotica research, in particular that the overrepresentation of erectile dysfunction yet underrepresentation of sexuality-related shame in volunteers

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2442-477: Is a necessity of life, just as air, food, and warmth." And yet there is no empirical evidence in support of such a parallel, Imieliński says. Sensations of hunger and thirst occur due to certain states of physiological insufficiency. The feeling of hunger results from the lack of glucose, fats and amino acids in blood. The feeling of thirst occurs in response to reduction of the water content of tissues. None of similar states of physiological deficiency responsible for

2553-507: Is applicable to humans remains unknown. Unambiguous experimental evidence for the existence of the Tarkhanov regularity in human sexual behaviour has never been obtained. Another explanation of sexual arousal is offered by the approach, which Kazimierz Imieliński calls the "psychohydraulic model of sexuality". This point of view likens human sexuality to a steam boiler, with biological processes or internal irritants creating sexual tension. If

2664-468: Is at least as fast as male erection. They also argue that the appearance of a greater individual variability in female genital response than in male genital response is consistent with a representative female sample and a male sample subject to bias that leaves much of the individual variability unstudied, with a reference to the neurological observation that all brain structures display significant individual variability in both sexes and that no brain structure

2775-429: Is complex, with a wide range of factors increasing or decreasing sexual arousal. Physiological responses, such as heart rate , blood pressure , and erection , are often discordant with self-reported subjective perceptions of arousal. This inconsistency suggests that psychological or cognitive aspects also have a strong effect on sexual arousal. The cognitive aspects of sexual arousal in men are not completely known, but

2886-464: Is consistent with the hypothesis that genital response to both sexual relevance and appeal allows for a stronger erectile function than response only to appeal and that a majority of the male population are ashamed of their responses to unappealing stimuli, accounting for the discrepancy between the report from most heterosexual couples that male erection is faster than female lubrication and the appearance on pletysmography volunteers that female lubrication

2997-471: Is likely that the man will continue to ejaculate and orgasm fully, with or without further stimulation. Equally, if sexual stimulation stops before orgasm, the physical effects of the stimulation, including the vasocongestion , will subside in a short time. Repeated or prolonged stimulation without orgasm and ejaculation can lead to discomfort in the testes (corresponding to the slang term " blue balls " ). After orgasm and ejaculation, men usually experience

3108-553: Is more commonly found amongst men than women. Heterosexual men experience much higher genital and subjective arousal to women than to men. This pattern is reversed for homosexual men. Studies have found that women have a non-category-specific genital response pattern of sexual arousal, meaning their genital responses are only modestly related to their preferred category. On the other hand, female subjective responses are category-specific, because they typically report their highest level of arousal to their preferred stimulus, although

3219-401: Is pleasurable and painful at the same time. With an increase of sexual excitation, the tension increases and becomes wholly unpleasurable. This condition becomes so unbearable that the individual is forced to seek release from these tensions and liberation from the painful feelings. ... The pain of tension which accompanies the increase in the intensity of the instinctual drives changes, with

3330-414: Is the recurrent laryngeal nerve . From the left vagus nerve the recurrent laryngeal nerve hooks around the aorta to travel back up to the larynx and proximal esophagus while, from the right vagus nerve, the recurrent laryngeal nerve hooks around the right subclavian artery to travel back up to the same location as its counterpart. These different paths are a direct result of embryological development of

3441-424: Is the so-called respiratory sinus arrhythmia (RSA). RSA is described as the physiological and rhythmical fluctuation of heart rate at the respiration frequency, characterized by heart rate increase during inspiration and decrease during expiration. Another role that the parasympathetic nervous system plays is in sexual activity. In males, the cavernous nerves from the prostatic plexus stimulate smooth muscles in

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3552-470: Is usually the most prominent and reliable sign of sexual arousal in males. In a woman, sexual arousal leads to increased blood flow to the clitoris and the rest of the vulva , as well as vaginal transudation - the seeping of moisture through the vaginal walls, which serves as lubrication . In males: It is normal to correlate the erection of the penis with male sexual arousal. Physical or psychological stimulation, or both, leads to vasodilation and

3663-636: Is variable only in females and not in males. Sexual arousal results in a combination of physiological and psychological factors, like genital sexual response and subjective experience of sexual arousal. The degree to which genital and subjective sexual response correspond is termed concordance . Arousal non-concordance is when there is no link, for example, in morning erection, which happens both with men ( nocturnal penile tumescence ) and women ( nocturnal clitoral tumescence ), or in cases of rape where research confirms reports of an arousal non-concordance orgasm or orgasm alike event can take place – presumably as

3774-410: The breasts , nipples , buttocks and/or genitals , and further sexual activity . Erotic stimuli may originate from a source unrelated to the object of subsequent sexual interest. For example, many people may find nudity , erotica or pornography sexually arousing. This may generate a general sexual interest that is satisfied by sexual activity. When sexual arousal is achieved by or dependent on

3885-409: The muscarinic and nicotinic cholinergic receptors. Most transmissions occur in two stages: When stimulated, the preganglionic neuron releases ACh at the ganglion , which acts on nicotinic receptors of postganglionic neurons. The postganglionic neuron then releases ACh to stimulate the muscarinic receptors of the target organ. Niconitic receptors transmit outgoing signals from the presynaptic to

3996-474: The pelvic splanchnic nerves , also act as parasympathetic nerves. Owing to its location, the parasympathetic system is commonly referred to as having "craniosacral outflow", which stands in contrast to the sympathetic nervous system, which is said to have "thoracolumbar outflow". The parasympathetic nerves are autonomic or visceral   branches of the peripheral nervous system (PNS). Parasympathetic nerve supply arises through three primary areas: As in

4107-407: The peritoneal cavity becomes inflamed or if the bowel is suddenly distended, the body will interpret the afferent pain stimulus as somatic in origin. This pain is usually non-localized. The pain is also usually referred to dermatomes that are at the same spinal nerve level as the visceral afferent synapse . Heart rate is largely controlled by the heart's internal pacemaker activity. Considering

4218-443: The sympathetic nervous system , which is responsible for stimulating activities associated with the fight-or-flight response . Nerve fibres of the parasympathetic nervous system arise from the central nervous system . Specific nerves include several cranial nerves , specifically the oculomotor nerve , facial nerve , glossopharyngeal nerve , and vagus nerve . Three spinal nerves in the sacrum (S2–4), commonly referred to as

4329-414: The zygomatic division of CN V 2 and travels on a communicating branch to unite with the lacrimal nerve (branch of the ophthalmic nerve of CN V 1 ) before synapsing at the lacrimal gland. These parasympathetic to the lacrimal gland control tear production. A separate group of parasympathetic leaving from the pterygopalatine ganglion are the descending palatine nerves (CN V 2 branch), which include

4440-575: The Kinsey Institute, explores the individual variability of sexual response . They postulate that this variability depends on the interaction between an individual's sexual excitation system (SES) and sexual inhibition system (SIS). Popularized by Emily Nagoski 's self-help book Come as You Are , the SES has been described as the sexual response's 'accelerator' and the SIS as the 'brake'. The SIS/SES questionnaire

4551-508: The Latin word vagus (because the nerve controls such a broad range of target tissues – vagus in Latin literally means "wandering"), contains parasympathetic fibers that originate in the dorsal nucleus of the vagus nerve and the nucleus ambiguus in the CNS. The vagus nerve can be readily identified in the neck both on ultrasound and magnetic resonance imaging. It has several branches. The largest branch

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4662-578: The SESII-W (the Sexual Excitation/Sexual Inhibition Inventory for Women) was created by Graham and associates. Female focus groups found that the context of the emotional relationship between sexual partners was not fully represented in the original SIS/SES questionnaire. A factor analysis of this questionnaire revealed only two factors: sexual excitation (SE) and sexual inhibition (SI). This may point to internal inconsistencies in

4773-427: The SESII-W found that bisexual women scored higher on SES than the other groups and heterosexual women scored higher on the sexual inhibition factor than both the lesbian and bisexual women. More studies need to be done using the dual control model to gain a more broad view of sexual orientation and sexual arousability. One way to study sexual arousal in women and men is to conduct sexual psychophysiological research in

4884-460: The SIS/SES questionnaire regarding gender. One lower order factor in the SESII-W labeled Arousal Contingency was particularly relevant; this factor explains the easy disruption of sexual arousal. Regardless of the difference in these two questionnaires, both surveys' scores show normal distribution verifying the hypothesis that there is a normal individual variation in sexual arousal and inhibition. In

4995-467: The absence of an orgasm. Depending on the situation, a person can be sexually aroused by a variety of factors, both physical and mental. A person may be sexually aroused by another person or by particular aspects of that person, or by a non-human object. The physical stimulation of an erogenous zone or acts of foreplay can result in arousal, especially if it is accompanied with the anticipation of imminent sexual activity. Sexual arousal may be assisted by

5106-476: The activity of the intestinal musculature, increasing gastric secretion, and relaxing the pyloric sphincter. It is called the “rest and digest” division of the ANS. The parasympathetic nervous system decreases respiration and heart rate and increases digestion. Stimulation of the parasympathetic nervous system results in: The terminology ‘Parasympathetic nervous system’ was introduced by John Newport Langley in 1921. He

5217-447: The anterior two-thirds of the tongue by way of the chorda tympani , and of the palate by way of the greater petrosal nerve , From the ganglion, the proximal fibres proceed to the gustatory (i.e. superior/rostral ) part of the solitary nucleus where they synapse with second-order neurons. The geniculate ganglion is conical in shape. The greater petrosal nerve diverges from CNVII and the lesser petrosal nerve diverges from CN IX at

5328-481: The aorta to disperse with the blood vessels and sympathetic nerves throughout the abdomen. The extent of the parasympathetic in the abdomen include the pancreas, kidneys, liver, gall bladder , stomach and gut tube. The vagus contribution of parasympathetic continues down the gut tube until the end of the midgut . The midgut ends two thirds of the way across the transverse colon near the splenic flexure . The pelvic splanchnic nerves , S2–4, work in tandem to innervate

5439-434: The assumption that men are always sexually interested in what causes genital arousal removes its own falsifiability by explaining all contradictory data away as "denial", making the theory untestable. While there is disagreement among neurologists on whether or not it is possible to categorically distinguish male brains and female brains by measuring many variables in the brain, neurologists agree that all single variables in

5550-414: The attempted elucidation of their role in other animals' sexual behaviour has been the object of experimental effort. No generalisation has yet appeared, however. The study performed by Beach & Wilson ( University of California, Berkeley ) in 1964 discovered that these glands do not participate in the regulation of sexual arousal of male rats in the similar manner. Whether the regularity observed in frogs

5661-411: The attractive object. The second stage, approach response, progresses from the first and involves bodily movements towards the object. The final genital response stage recognizes that with both attention and closer proximity, physical reactions result in genital tumescence. Singer also stated that there is an array of other autonomic responses, but acknowledges that the research literature suggests that

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5772-420: The autonomic nervous system, in which the parasympathetic nervous system receives input from cranial nerves exclusively and the sympathetic nervous system from thoracic to sacral spinal nerves. The afferent fibers of the autonomic nervous system, which transmit sensory information from the internal organs of the body back to the central nervous system, are not divided into parasympathetic and sympathetic fibers as

5883-414: The bladder and the urethra, allowing the bladder to void. Also, parasympathetic stimulation of the internal anal sphincter will relax this muscle to allow defecation. There are other skeletal muscles involved with these processes but the parasympathetic plays a huge role in continence and bowel retention. A study published in 2016, suggests that all sacral autonomic output may be sympathetic; indicating that

5994-435: The bladder. At the same time, parasympathetics cause peristalsis of the urethral muscle, and the pudendal nerve causes contraction of the bulbospongiosus (skeletal muscle is not via PN), to forcibly emit the semen. During remission the penis becomes flaccid again. In the female, there is erectile tissue analogous to the male yet less substantial that plays a large role in sexual stimulation. The PN cause release of secretions in

6105-546: The body's response is engorged sexual tissues such as nipples , clitoris , vaginal walls , and vaginal lubrication . Mental stimuli and physical stimuli such as touch, and the internal fluctuation of hormones , can influence sexual arousal. Sexual arousal has several stages and may not lead to any actual sexual activity beyond a mental arousal and the physiological changes that accompany it. Given sufficient sexual stimulation, sexual arousal reaches its climax during an orgasm . It may also be pursued for its own sake, even in

6216-487: The body. The axons of presynaptic parasympathetic neurons are usually long, extending from the CNS into a ganglion that is either very close to or embedded in their target organ. As a result, the postsynaptic parasympathetic nerve fibers are very short. The oculomotor nerve is responsible for a number of parasympathetic functions related to the eye. The oculomotor PNS fibers originate in the Edinger-Westphal nucleus in

6327-449: The brain display more individual variation and overlap between the sexes than differences between the sexes. For instance, men and women alike are capable of classifying sex acts as sexual no matter if they find them appealing or not, making a genital response to unappealing erotic stimuli a single mechanism step. It is therefore argued by neurologists that category specificity of genital response to erotical imagery, being determined by one or

6438-406: The central nervous system and travel through the superior orbital fissure to synapse in the ciliary ganglion located just behind the orbit (eye). From the ciliary ganglion the postganglionic parasympathetic fibers leave via short ciliary nerve fibers, a continuation of the nasociliary nerve (a branch of ophthalmic division of the trigeminal nerve (CN V 1 )). The short ciliary nerves innervate

6549-406: The circulatory system. Each recurrent laryngeal nerve supplies the larynx, the heart, the trachea and the esophagus. Another set of nerves that come off the vagus nerves approximately at the level of entering the thorax are the cardiac branches of the vagus nerve . These cardiac branches go on to form cardiac and pulmonary plexuses around the heart and lungs. As the main vagus nerves continue into

6660-401: The cochlear promontory of the mesotympanum. The tympanic plexus of nerves rejoin and form the lesser petrosal nerve and exit through the foramen ovale to synapse at the otic ganglion . From the otic ganglion postganglionic parasympathetic fibers travel with the auriculotemporal nerve (mandibular branch of trigeminal, CN V 3 ) to the parotid salivary gland. The vagus nerve , named after

6771-423: The crucial role in the generation of sexual excitement in frogs. Proceeding from these experimental results, Tarkhanov put forward a hypothesis that filling and evacuation of the seminal vesicles were the main biological cause, which led to sexual arousal and its disappearance in humans and other mammals. Ever since Tarkhanov's findings demonstrated sexual arousal in frogs to result from the state of seminal vesicles,

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6882-411: The discharge, into the pleasure of relaxation. After a certain time, the same process begins anew. Such an approach assumes sexual arousal to be a spontaneous desire that appears periodically like sensations of hunger and thirst. Drawing a parallel between these sensations and sexual excitation is widely accepted now: "Everyone must experience sexuality in some way to survive. ... In this sense sex

6993-430: The efferent fibers are. Instead, autonomic sensory information is conducted by general visceral afferent fibers . General visceral afferent sensations are mostly unconscious visceral motor reflex sensations from hollow organs and glands that are transmitted to the CNS. While the unconscious reflex arcs normally are undetectable, in certain instances they may send pain sensations to the CNS masked as referred pain . If

7104-514: The environment invade the nervous system, which results in sexual motivation. Positive sexual experiences enhance motivation, while negative experiences reduce it. Motivation and behaviour are organized hierarchically ; each are controlled by a combination of direct (external stimuli) and indirect (internal cognitions) factors. Excitation and inhibition of behavior act at various levels of this hierarchical structure. For instance, an external stimulus may directly excite sexual arousal and motivation below

7215-415: The eye fixated on an object. The visceral motor helps constrict the pupil. The parasympathetic aspect of the facial nerve controls secretion of the sublingual and submandibular salivary glands , the lacrimal gland , and the glands associated with the nasal cavity. The preganglionic fibers originate within the CNS in the superior salivatory nucleus and leave as the intermediate nerve (which some consider

7326-551: The female that decrease friction. Also in the female, the parasympathetics innervate the fallopian tubes , which helps peristaltic contractions and movement of the oocyte to the uterus for implantation. The secretions from the female genital tract aid in sperm migration. The PN (and SN to a lesser extent) play a significant role in reproduction. The parasympathetic nervous system uses chiefly acetylcholine (ACh) as its neurotransmitter , although peptides (such as cholecystokinin ) can be used. The ACh acts on two types of receptors,

7437-402: The fibrous trabeculae of the coiled helicine arteries of penis to relax and allow blood to fill the two corpora cavernosa and the corpus spongiosum of the penis, making it rigid to prepare for sexual activity. Upon emission of ejaculate, the sympathetics participate and cause peristalsis of the ductus deferens and closure of the internal urethral sphincter to prevent semen from entering

7548-484: The functions of the parasympathetic nervous system is SSLUDD ( sexual arousal , salivation , lacrimation , urination , digestion and defecation ). The functions promoted by activity in the parasympathetic nervous system are associated with our day-to-day living. The parasympathetic nervous system promotes digestion and the synthesis of glycogen , and allows for normal function and behavior. Parasympathetic action helps in digestion and absorption of food by increasing

7659-402: The geniculate ganglion. It is located close to the internal auditory meatus . It is covered superiorly by the petrous part of the temporal bone (which is sometimes absent over the ganglion). The geniculate ganglion is an important surgical landmark near the internal auditory meatus . The geniculate ganglion may become inflamed due herpes zoster virus virus infection. Swelling of

7770-402: The genital and other regions may lead to a sex flush in some men. As sexual stimulation continues, orgasm begins, when the muscles of the pelvic floor , the vasa deferentia (between the testicles and the prostate), the seminal vesicles and the prostate gland itself may begin to contract in a way that forces sperm and semen into the urethra inside the penis. Once this has started, it

7881-404: The genital response is the most reliable and convenient to measure in males. In 2000, Rosemary Basson presented an alternative model to the human sexual response cycle that is specific to women's sexual response . She argues that gender differences in sex drive , sexual motivation, sexual concordance, and capacity for orgasm underlie the need for an alternative model of sexual response. While

7992-461: The greater and lesser palatine nerves. The greater palatine parasympathetic synapse on the hard palate and regulate mucous glands located there. The lesser palatine nerve synapses at the soft palate and controls sparse taste receptors and mucous glands. Yet another set of divisions from the pterygopalatine ganglion are the posterior, superior, and inferior lateral nasal nerves; and the nasopalatine nerves (all branches of CN V 2 , maxillary division of

8103-481: The heart rate in the range of 60-100 beats per minute (bpm). At the same time, the two branches of the autonomic nervous system act in a complementary way increasing or slowing the heart rate. In this context, the vagus nerve acts on sinoatrial node slowing its conduction thus actively modulating vagal tone accordingly. This modulation is mediated by the neurotransmitter acetylcholine and downstream changes to ionic currents and calcium of heart cells. The vagus nerve plays

8214-477: The heritability of both factors of SIS, but research suggests that SES variability is down to environmental factors. The majority of studies investigating sexual functioning use heterosexual participants exclusively, limiting the generalizability of the dual control model. One study comparing heterosexual and gay men found that gay men had similar scores for SIS2, but scored significantly higher for SIS1 and SES. Heterosexual, lesbian, and bisexual women's scores on

8325-411: The human sexual response cycle begins with desire, followed by arousal, orgasm, and finally resolution, Basson's alternative model is circular and begins with women feeling a need for intimacy , which leads her to seek out and be receptive to sexual stimuli; women then feel sexual arousal, in addition to sexual desire . The cycle results in an enhanced feeling of intimacy. Basson emphasizes the idea that

8436-512: The increased blood flow engorges the three spongy areas that run along the length of the penis (the two corpora cavernosa and the corpus spongiosum ). The penis grows enlarged and firm, the skin of the scrotum is pulled tighter, and the testicles are pulled up against the body. However, the relationship between erection and arousal is not one-to-one (arousal non-concordance). After their mid-forties, some men report that they do not always have an erection when they are sexually aroused. Equally,

8547-557: The inside of his clothing to maintain and encourage it for some time. As sexual arousal and stimulation continues, it is likely that the glans or head of the erect penis will swell wider and, as the genitals become further engorged with blood, their color deepens and the testicles can grow up to 50% larger. As the testicles continue to rise, a feeling of warmth may develop around them and the perineum . With further sexual stimulation, their heart rate increases, blood pressure rises and breathing becomes quicker. The increase in blood flow in

8658-675: The intensity of orgasms, and then cause more rapid resolution. The uterus typically contracts during orgasm and, with advancing age, those contractions may actually become painful. Psychological sexual arousal involves appraisal and evaluation of a stimulus, categorization of a stimulus as sexual, and an affective response. The combination of cognitive and physiological states elicits psychological sexual arousal. Some suggest that psychological sexual arousal results from an interaction of cognitive and experiential factors, such as affective state, previous experience, and current social context. The relationship between sexual desire and arousal in men

8769-475: The internal organs also occur including to the internal shape of the vagina and to the position of the uterus within the pelvis . Other changes include an increase in heart rate as well as in blood pressure , feeling hot and flushed and perhaps experiencing tremors. A sex flush may extend over the chest and upper body. If sexual stimulation continues, then sexual arousal may peak into orgasm . After orgasm, some women do not want any further stimulation and

8880-412: The labia. More recently, laser doppler imaging (LDI) has been used as a direct measure of genital sexual arousal in women. LDI functions by measuring superficial changes in blood flow in the vulvar tissues. The most obvious response involved with sexual behaviour in males is penile erection . The use of the volume (or circumference) change during penile erection as a convenient measure of sexual arousal

8991-458: The level of this tension reaches threshold, sexual arousal occurs as the expression of necessity to let off steam. Gary F. Kelly ( Clarkson University ) describes this model as follows: For centuries, the assumption was made that the longing for sexual interaction was innate, and an inner drive model was used to explain it. It has been suggested that this model was much like a metaphor for a steam boiler. Internal sexual "steam" would build up until

9102-401: The lingual nerve, the preganglionic fibers synapse at the submandibular ganglion and send postganglionic fibers to the sublingual and submandibular salivary glands. The glossopharyngeal nerve has parasympathetic fibers that innervate the parotid salivary gland. The preganglionic fibers depart CN IX as the tympanic nerve and continue to the middle ear where they make up a tympanic plexus on

9213-642: The magnitude of arousal need not be consistent. That is, the hypothesis is that vaginal lubrication can take place as a protective mechanism even in a non-preferred sexual situation, such as when sexual activity is non-consensual . Other researchers argue that since the research is done on people who volunteer to be studied, the observed levels of category specificity may not represent the population, that there may be different cultural expectations of sexual interests being linked to genital arousal that make men with non-category specific genital arousal less likely to appear as test subjects. There researchers also argue that

9324-411: The maturity, age, culture and other factors influencing the person. However, when a person fails to be aroused in a situation that would normally produce arousal and the lack of arousal is persistent, it may be due to a sexual arousal disorder or hypoactive sexual desire disorder . There are many reasons why a person fails to be aroused, including a mental disorder, such as depression , drug use , or

9435-454: The middle ear and eventually combines with the deep petrosal nerve (sympathetic fibers) to form the nerve of the pterygoid canal . The parasympathetic fibers of the nerve of the pterygoid canal synapse at the pterygopalatine ganglion , which is closely associated with the maxillary division of the trigeminal nerve (CN V 2 ). The postganglionic parasympathetic fibers leave the pterygopalatine ganglion in several directions. One division leaves on

9546-405: The orbit to control the ciliary muscle (responsible for accommodation ) and the iris sphincter muscle , which is responsible for miosis or constriction of the pupil (in response to light or accommodation). There are two motors that are part of the oculomotor nerve known as the somatic motor and visceral motor. The somatic motor is responsible for moving the eye in precise motions and for keeping

9657-403: The original SIS/SES questionnaire, statistically significant gender differences are seen despite considerable overlap in scores between men and women. On average, males score higher on sexual excitation and lower than females on both facets of sexual inhibition. The differences in scores between genders have not been explained beyond the theoretical level. The source of individual variability on

9768-429: The other three. Erotic stimuli which can result in sexual arousal can include conversation, reading, films or images, or a smell or setting, any of which can generate erotic thoughts and memories in a person. Given the right context, these may lead to the person desiring physical contact, including kissing , cuddling , and petting of an erogenous zone. This may in turn make the person desire direct sexual stimulation of

9879-433: The parasympathetic will cause peristaltic movements of the ureters and intestines, moving urine from the kidneys into the bladder and food down the intestinal tract and, upon necessity, the parasympathetic will assist in excreting urine from the bladder or defecation. Stimulation of the parasympathetic will cause the detrusor muscle (urinary bladder wall) to contract and simultaneously relax the internal sphincter muscle between

9990-454: The pathway do not synapse in a ganglion as in the cranium but rather in the walls of the tissues or organs that they innervate. The fiber paths are variable and each individual's autonomic nervous system in the pelvis is unique. The visceral tissues in the pelvis that the parasympathetic nerve pathway controls include those of the urinary bladder, ureters, urinary sphincter, anal sphincter, uterus, prostate, glands, vagina, and penis. Unconsciously,

10101-499: The pelvic viscera . Unlike in the cranium, where one parasympathetic is in charge of one particular tissue or region, for the most part the pelvic splanchnics each contribute fibers to pelvic viscera by traveling to one or more plexuses before being dispersed to the target tissue. These plexuses are composed of mixed autonomic nerve fibers (parasympathetic and sympathetic) and include the vesical, prostatic, rectal, uterovaginal, and inferior hypogastric plexuses. The preganglionic neurons in

10212-532: The periodical appearance of sexual arousal has been revealed in human sexuality. Sexual arousal in women is characterized by vasocongestion of the genital tissues, including internal and external areas (e.g., vaginal walls , clitoris , and labia ). There are a variety of methods used to assess genital sexual arousal in women. Vaginal photoplethysmography (VPG) can measure changes in vaginal blood volume or phasic changes in vasocongestion associated with each heartbeat. Clitoral photoplethysmography functions in

10323-523: The physiological measurements of sexual arousal. Studies have found temperature change specific to the genitals during sexual arousal, which supports the validity of this measure. Category-specificity refers to a person showing sexual arousal to the categories of people they prefer to have sex with. Sexual arousal studies involving category-specificity look at genital responses (physiological changes), as well as subjective responses (what people report their arousal levels to be). Category-specific sexual arousal

10434-983: The postsynaptic cells within the sympathetic and parasympathetic nervous system, and are the receptors used in the somatic nervous system for signalling muscular contraction in the neuromuscular junction . The muscarinic receptors are mainly present in the parasympathetic nervous system but also appear in the sweat glands of the sympathetic nervous system. The five main types of muscarinic receptors: In vertebrates, nicotinic receptors are broadly classified into two subtypes based on their primary sites of expression: muscle-type nicotinic receptors (N1) primarily for somatic motor neurons; and neuronal-type nicotinic receptors (N2) primarily for autonomic nervous system. Sympathetic and parasympathetic divisions typically function in opposition to each other. The sympathetic division typically functions in actions requiring quick responses. The parasympathetic division functions with actions that do not require immediate reaction. A mnemonic to summarize

10545-490: The pressure became so great that the drive to release it was very strong. This view also assumed that there was some adverse physical consequence of not releasing the pressure. The "psychohydraulic model of sexuality" has been formulated most definitely in psychoanalysis : The instinct causes tensions within the central nervous system, which spread out over the whole being; it is urgent and irresistible in nature and constantly repeats itself. ... An erection, for example,

10656-407: The rectum, bladder and reproductive organs may only be innervated by the sympathetic nervous system. This suggestion is based on detailed analysis of 15 phenotypic and ontogenetic factors differentiating sympathetic from parasympathetic neurons in the mouse. Assuming that the reported findings most likely applies to other mammals as well, this perspective suggests a simplified, bipartite architecture of

10767-408: The reported difference in levels of arousal is typically much smaller than those in men. A possible explanation for the non-category specific genital arousal in women, which also accounts for their high individual variation, is the "preparation hypothesis". This hypothesis suggests that, provided there is enough of an increase in vaginal blood flow for vaginal lubrication to occur in a sexual context,

10878-717: The right stimulation in the right circumstances, there are physical and psychological changes to women's sexual arousal and responses as they age. Older women produce less vaginal lubrication and studies have investigated changes to degrees of satisfaction, frequency of sexual activity, to desire, sexual thoughts and fantasies , sexual arousal, beliefs about and attitudes to sex, pain, and the ability to reach orgasm in women in their 40s and after menopause . Other factors have also been studied including socio-demographic variables, health, psychological variables, partner variables such as their partner's health or sexual problems, and lifestyle variables. It appears that these other factors often have

10989-1000: The sex of the actors portrayed in the stimulus, and men may be more likely than women to objectify the actors. There are reported differences in brain activation to sexual stimuli, with men showing higher levels of amygdala and hypothalamic responses than women. This suggests the amygdala plays a critical role in the processing of sexually arousing visual stimuli in men. Research suggests that cognitive factors like sexual motivation, perceived gender role expectations, and sexual attitudes play important roles in women's self-reported levels of sexual arousal. In her alternative model of sexual response, Basson suggests that women's need for intimacy prompts them to engage with sexual stimuli, which leads to an experience of sexual desire and psychological sexual arousal. Psychological sexual arousal also has an effect on physiological mechanisms; Goldey and van Anders showed that sexual cognitions impact hormone levels in women, such that sexual thoughts result in

11100-437: The sexual arousal quickly dissipates. Suggestions have been published for continuing the sexual excitement and moving from one orgasm into further stimulation and maintaining or regaining a state of sexual arousal that can lead to second and subsequent orgasms. Some women have experienced such multiple orgasms quite spontaneously. While young women may become sexually aroused quite easily, and reach orgasm relatively quickly with

11211-494: The sexual excitation and inhibition systems is not known definitively. Even less is known about how these systems develop in individuals. Age of first masturbation has been used as a measure to assess sexual development. Age of masturbatory onset is much more variable in girls than boys, whose tend to be close to puberty. Researchers have not determined whether this gender difference is biological in nature or influenced by sociocultural values. One twin-study has found evidence for

11322-422: The state does involve the appraisal and evaluation of the stimulus, categorization of the stimulus as sexual, and an affective response. Research suggests that cognitive factors, such as sexual motivation, perceived gender role expectations, and sexual attitudes, contribute to sex differences observed in subjective sexual arousal. Specifically, while watching heterosexual erotic videos , men are more influenced by

11433-414: The sympathetic nervous system, efferent parasympathetic nerve signals are carried from the central nervous system to their targets by a system of two neurons . The first neuron in this pathway is referred to as the preganglionic or presynaptic neuron . Its cell body sits in the central nervous system and its axon usually extends to synapse with the dendrites of a postganglionic neuron somewhere else in

11544-466: The thorax they become intimately linked with the esophagus and sympathetic nerves from the sympathetic trunks to form the esophageal plexus. This is very efficient as the major function of the vagus nerve from there on will be control of the gut smooth muscles and glands . As the esophageal plexus enter the abdomen through the esophageal hiatus anterior and posterior vagus trunks form. The vagus trunks then join with preaortic sympathetic ganglion around

11655-477: The time necessary for sexual arousal. Researchers studied the time required for an individual to reach the peak of sexual arousal while watching sexually explicit movies or pictures and came to the conclusion that on average women and men took almost the same time for sexual arousal — around 10 minutes. The time needed for foreplay is strongly individual and varies from one occasion to the next depending on circumstances. Unlike many animals, humans do not have

11766-418: The trigeminal nerve) that bring parasympathetic innervation to glands of the nasal mucosa . The second parasympathetic branch that leaves the facial nerve is the chorda tympani. This nerve carries secretomotor fibers to the submandibular and sublingual glands. The chorda tympani travels through the middle ear and attaches to the lingual nerve (mandibular division of trigeminal, CN V 3 ). After joining

11877-595: The use of objects, it is referred to as sexual fetishism , or in some instances a paraphilia . There is a common belief that women need more time to achieve arousal. However, recent scientific research has shown that there is no considerable difference for the time men and women require to become fully aroused. Scientists from McGill University Health Centre in Montreal (in Canada) used the method of thermal imaging to record baseline temperature change in genital area to define

11988-420: The woman's subjective sensation of being sexually aroused: the findings usually are that in some cases there is a high correlation, while in others, it is surprisingly low. Further stimulation can lead to additional vaginal wetness and further engorgement and swelling of the clitoris and the labia , along with increased redness or darkening of the skin in these areas as blood flow increases. Further changes to

12099-489: Was developed to assess an individual's SIS and SES levels. A factor analysis of the SIS/SES questionnaire, revealed a single excitation factor and two inhibition factors. These inhibition factors were interpreted as SIS1 (inhibition due to the threat of performance failure) and SIS2 (inhibition due to the threat of performance consequences). The SIS/SES questionnaire was originally developed for men though it has since proven its statistical validity among women. Despite this,

12210-466: Was first developed by Kurt Freund . This measurement of blood flow to the male genitals is known as penile plethysmography. This is commonly measured using a strain gauge, a simple mercury strain gauge encompassed in a ring of rubber. The ring surrounds the penis , but does not constrict or cause discomfort. The measure has been found by some to be a reliable and valid measurement of male arousal. More recently, thermography has been developed to measure

12321-532: Was the first person who put forward the concept of PSNS as the second division of the autonomic nervous system. Sexual arousal Sexual arousal (also known as sexual excitement ) describes the physiological and psychological responses in preparation for sexual intercourse or when exposed to sexual stimuli . A number of physiological responses occur in the body and mind as preparation for sexual intercourse, and continue during intercourse. Male arousal will lead to an erection , and in female arousal ,

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