We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Published by Nathaniel Wilkins Modified over 2 years ago. Their dual control model envisions a balance between sexual activation and sexual inhibition in an individual's brain, with this balance determining whether sexual stimulation leads to arousal Bancroft and Graham proposed dual control theories for sexual motivation in men and women.
Their dual control model envisions a balance between sexual activation and sexual inhibition in an individual's brain, with this balance determining whether sexual stimulation leads to arousal.
The excitation factors included sexual arousability, partner characteristics, sexual power dynamics, smell, and setting. The inhibition factors were: Men generally show greater responsiveness to visual sexually arousing stimuli than women do.
In a study of surgically menopausal women who were sexually active but were receiving no hormonal therapy.
When these women viewed erotica during functional magnetic resonance imaging MRIthey failed to display the brain activation observed in premenopausal women or in themselves when they were treated with testosterone
Boli cu transmitere sexuala wikipedia estrogen. In animal models, steroid hormones modulate sexual arousal by directing synthesis of the enzymes and the receptors for a number of neurotransmitters, including dopamine, noradrenalin, melanocortin, and oxytocin.
The role of testosterone in desire and arousal is better documented in men than in women. Systems that act within the hypothalamus and limbic regions of the brain are involved in the process of arousal, attention, and sexual behavior. It is thought that dopamine transmission in the medial preoptic area and the nucleus accumbens focuses the person's attention on sexual stimuli.
It is postulated that the behavioral pattern stimulated by those systems and the subjective feelings that accompany them constitute the phenomenon commonly referred to as sexual desire or arousal when genital sensations triggered by these systems are subjectively felt.
The main part of this neural pathway includes the medial preoptic area and its outputs to the ventral tegmental area. The latter contains dopamine cell bodies that project to various limbic and cortical regions, including the prefrontal cortex, the nucleus accumbens, the anterior cingulate cortex, Boli cu transmitere sexuala wikipedia the amygdala "Boli cu transmitere sexuala wikipedia" main part of this neural pathway includes the medial preoptic area and its outputs to the ventral tegmental area.
The latter contains dopamine cell bodies that project to various limbic and cortical regions, including the prefrontal cortex, the nucleus accumbens, the anterior cingulate cortex, and the amygdala.
It is thought that the behavioral pattern stimulated by the inhibitory pathways includes both sexual reward and satiety refractoriness. Brain pathways for sexual inhibition include opioid, endocannabinoid, and serotonin neural transmissions feeding back to various levels of the excitatory pathways. Low doses of opiates can have facilitatory effects, possibly through actions in the ventral tegmental area to activate the mesolimbic dopamine system. Exogenous opiates can induce an intense feeling of pleasure which has been likened to orgasm followed by a state of relaxation and calm.
Administration of melanocortin receptor agonists has been associated with an increase in spontaneous erection in healthy men and in men with ED and with increased desire, but not genital responses, in women.
Melanocortins are derived from pro-opiomelanocortin and modulate sexual response through a specific receptor subtype, the melanocortin-4 receptor.
Oxytocin levels increase close to orgasm. This hormone is known to be involved in pair bonding in some animal species, but its relevance in humans is not known. High levels of prolactin are associated with impaired sexual function in men and women.
Whereas subjective arousal is typically concordant with genital congestion in men, there is a poor correlation between subjective arousal and measures of genital congestion in women.
Also, in contrast to men's assessment of their erections, women's assessment of their degree of genital congestion is less accurate. Men and women differ substantially with respect to the correlation between genital congestion and Boli cu transmitere sexuala wikipedia sexual arousal excitement. It is thought that genital congestion in women is a prompt, automatic reflex that occurs within seconds of an erotic stimulus; it may not be deemed at all sexually arousing by the woman, or it may even be deemed emotionally negativ It is thought that genital congestion in women is a prompt, automatic reflex that occurs within seconds of Boli cu transmitere sexuala wikipedia erotic stimulus; it may not be deemed at all sexually arousing by the woman, or it may even be deemed emotionally negativ.
Neurons in paraventricular nuclei project onto the thoracolumbar and sacral nuclei associated with erections.
The medial preoptic area of the hypothalamus serves as the integration site for the Boli cu transmitere sexuala wikipedia nervous system control of erections; it receives sensory input from the amygdala and Boli cu transmitere sexuala wikipedia impulses to the paraventricular nuclei of the hypothalamus and the periaqueductal gray matter.
The parasympathetic input to the penis is proerectile, and sympathetic input is mainly inhibitory. Penile erection results from a series of biochemical and hemodynamic events that are associated with activation of central nervous system sites involved in regulation of erections, relaxation of cavernosal smooth muscle, increased blood flow into cavernosal sinuses, and venous occlusion resulting in penile engorgement and rigidity.
Normal penile erection requires coordinated involvement of intact central and peripheral nervous systems, corpora cavernosa and spongiosa, and normal arterial blood supply and venous drainage. In healthy men, there is the associated ejaculation, and in both genders, there are involuntary reflexive muscular contractions of the striated perineal muscles Orgasm is a subjective experience in both men and women, and it has been difficult to determine an objective marker.
In healthy men, there is the associated ejaculation, and in both genders, there are involuntary reflexive muscular contractions of the striated perineal muscles Positron emission tomography studies during orgasm have shown largely similar brain activations and deactivations in both men and women: Positron emission tomography studies during orgasm have shown largely similar brain activations and deactivations in both men and women: Is persistent or recurrent deficiency or absence of sexual fantasies and desire for sexual activity that causes marked distress or interpersonal difficulty and that is not better explained by another disorder, direct physiologic effects of a substance i.
Low sexual desire is not necessarily pathologic; it may be an appropriate adaptation to relationship and health-related issues Low sexual desire is not necessarily pathologic; it may be an Boli cu transmitere sexuala wikipedia adaptation to relationship and health-related issues.
Androgen deficiency is an important, treatable cause of hypoactive sexual desire disorder and should be excluded by measuring serum total testosterone levels. Hypoactive sexual desire disorder often coexists with other sexual disorders, such as ED, and may develop as a consequence of other preexisting sexual disorders. Sexual dysfunction is a more general term that also includes libidinal, orgasmic, and ejaculatory dysfunction, in addition to the inability to attain or maintain penile erection.
ED significantly affects quality of life of both the affected individual and his partner. In one study, ED had a negative impact on the sexual life of female partners, specifically on their "Boli cu transmitere sexuala wikipedia" satisfaction and sexual drive. The risk factors for ED include age, diabetes mellitus, hypertension, smoking, medication use, depression, dyslipidemia, and cardiovascular disease.
Advancing age is an important risk factor for ED in men: Ejaculatory disorders are at least as prevalent and may be even more prevalent than ED. Premature ejaculation, defined as ejaculation associated with lack of or poor ejaculatory control that causes distress in one or both partners, is the most prevalent sexual disorder in men 18 to 59 years of age.
Delayed ejaculation refers to inability to ejaculate in a reasonable period that interferes with sexual or emotional satisfaction and is associated with distress.