The physiology of arousal in the male is elicited in numerous ways. The neurological mechanisms are what we have an interest in for this course. Sensory organs detect anal stimulation, skin stimulation, perineal stimulation as well as friction on the glans penis. All of these sensations are transmitted via the pudendal nerve to the sacral plexus. In addition, an inflamed/irritated urethra, bladder, prostate, seminal vesicles, testes and/or vas deferens drives transmissions to the sacral plexus. Likewise, the male's sexual drive causes sexual organs to overfill causing increased secretions and vasocongestion. These signals are also transmitted to the sacral plexus. Signals from the sacral plexus travel two directions: 1) back to the penis, causing the penile arterial pressure to increase and blocking venous sinusoidal drainage and 2) to an "uncharted" region of the cerebrum. The bottom line is that these signals all "cause" sexual sensation.
The physiology of arousal in the female is elicited in numerous ways. The neurological mechanisms are what we have an interest in for this course. Sensory organs detect anal stimulation, groin stimulation, perineal stimulation as well as friction on the glans clitoris and labia or in the labial groove. All of these sensations are transmitted via the pudendal nerve to the sacral plexus. In addition, an inflamed/irritated urethra or bladder drives transmissions to the sacral plexus. Likewise, the female's sexual drive causes sexual organs to overfill causing increased secretions and vasocongestion. Furthermore, emotional states, learned behaviors and blood levels of estrogens, progesterone and corticoids govern the female's sexual drive. These signals are also transmitted to the sacral plexus. Signals from the sacral plexus travel two directions: 1) back to the clitoris, causing the clitoral arterial pressure to increase and blocking venous sinusoidal drainage and 2) to an "uncharted" region of the cerebrum. The bottom line is that these signals all "cause" sexual sensation. Nipple erection during this stage is due to small muscle fiber contraction during sexual excitement.
In both sexes, the psyche is important, i.e., thinking, dreaming, fantasizing about things of a sexual nature enhances the stage of arousal. Ultimately, this all leads to orgasm in the female and ejaculation in the male (particularly nocturnal emission in the pubescent male).
The physiology of male erection depends upon the degree of sexual stimulation he is receiving. Erection is caused by parasympathetic impulses from the sacral cord (S2, S3, S4) to the penis. These same motor nerves innervate the ischiocavernosus and bulbospongiosus muscles. The result is that penile arterioles dilate and the penile venules constrict. This puts high-pressure blood flow into the corpus spongiosum and the corpora cavernosa. The penis becomes erect it is said to be in a state of TUMESCENCE, i.e., a condition of being swollen, or a swelling. The scrotum also begins to elevate as the penis becomes erect.
The physiology of female erection depends upon the degree of sexual stimulation he is receiving. Erection is caused by parasympathetic impulses from the sacral cord (S2, S3, S4) to the clitoris. These same motor nerves innervate the ischiocavernosus muscle. These same nerves cause the clitoris to retract under the clitoral hood, later. The result is that clitoral arterioles dilate and the clitoral venules constrict. This puts high-pressure blood flow into the corpora cavernosa. The clitoris becomes erect it is said to be in a state of TUMESCENCE, i.e., a condition of being swollen, or a swelling. During tumescence in the female, the introitus tightens by at least one-third due to venous congestion at the outer third of the vaginal barrel (location of the corpus spongiosum in the female). The vaginal barrel and labia minora thicken (called the orgasmic platform) due to VASOCONGESTION. The orgasmic platform "grips" the penis during intercourse, hence, penile size is only important psychologically, NOT physiologically. Vasocongestion is one of TWO primary physiological responses to sexual intercourse in both the male and female. NOTE: vaginal secretions increase and the uterus "swings" more to a posteroflexed position.
Lubrication in the male is a parasympathetic response. Cowper's glands secrete mucous through the urethra. This mucous washes out residual urine in the urethra and increases the pH for the sperm (sperm require an alkaline pH for survival). Cowper's glands are a SMALL aid to lubrication for coitus as they only secrete 2-3 drops of lubricant. MOST of the lubrication for coitus is from the female. Without lubrication, the sexual sensations are decreased and pain is sensed, instead. The scrotum (dartos, cremaster) contracts. The testes increase about 50% in size (vasocongestion) and elevate more. The penis changes colors due to vasocongestion from "skin color" to pink to bright/deep red.
Lubrication in the female is a parasympathetic response. Bartholin's glands secrete a slight amount of mucous. This mucous is NOT the primary mucous for coitus. MOST of the lubrication for coitus is due to the female's vaginal wall vasocongestion. Lubrication "squeezes" through the congested wall as a transudate. It provides for lubrication and it buffers the acidity (with semen) of the vagina for an appropriate sperm environment. It may be in levels so as to flow from the vagina and introitus moistening all tissues in its path, including the labia. Without lubrication, sexual sensations are decreased and pain is sensed, instead. The vagina changes colors due to vasocongestion from "skin color" to pink to bright/deep red..
Orgasm is the sudden discharge of accumulated sexual tension in a peak of sexual arousal.
Male orgasm, as mentioned, earlier, is a two-staged process. Emission is due to sympathetic impulses from L1 and L2. They innervate the urethral crest and muscles of the epididymis, vas deferens, seminal vesicles, prostate and penile shaft (the genital organs). Emission is the "forerunner" to ejaculation. Epididymal, vas deferens and ampullary contractions expel sperm to the internal urethra. Contractions of the seminal vesicles and prostate expel fluids and ALL fluids mix to make semen.
Ejaculation occurs when the internal urethra fills with semen. Signals are sent to the pudendal nerve via the sacral plexus/cord. Rhythmic nerve impulses are transmitted from L1 and L2. Once the prostate contracts, ejaculation is inevitable, i.e., nothing will stop ejaculation at this point, a point of no return. Skeletal perineal muscles at the base of the erectile tissues contract with wave-like increases in pressure ("squirts"). These spasms number about 4 to 5 in the prostate, seminal vesicles, vas deferens and urethra at 0.8-second intervals. Accompanying this are involuntary contractions of the internal and external sphincters. This last 3-15 seconds and is associated with a slight clouding of consciousness. Semen is ejaculated from the urethra to the exterior. The ejaculatory spurt is about 30-50 cm at 18 YOA and decreases from there to seepage by about 70 YOA. Muscles relax decreasing vasocongestion. The penis undergoes detumescence (unswelling) and the genitals disengorge. A sense of relaxation is felt.
In some instances (multiple sclerosis, diabetes, after some prostate surgeries), a male may experience retrograde ejaculations, i.e., he may ejaculate into his bladder -- this is due to destruction of his sphincter vesiculi.
Sympathetic nerves drive the female orgasm, as well. OT is secreted during orgasm in both sexes (causes uterus to contract in female and prostate in male). Perineal muscles contract giving 3-15 rhythmic spasms of the lower third of the vagina and uterus (from the fundus to the cervix). It is also known that the cervix "dips" down towards the vagina during orgasm associated with a decrease in pressure in the vagina. It is thought that this facilitates sperm movement into the uterus (if semen is present, of course). Involuntary spasms of both anal sphincters occur as well. Contractions/spasms occur at 0.8-second intervals for 3-15 seconds. Orgasm in females is also accompanied by a slight clouding of consciousness, a sense of satisfaction, peace and relaxation. Orgasm increases uterine and fallopian tube motility to increase chances of fertilization -- may be due to an increased rate of sperm transport. Orgasm is analogous to ejaculation in the male. The clitoris and vaginal barrel undergo detumescence just as the penis and testes. Ejaculatory inevitability does NOT happen in women, i.e., a female's orgasm can be stopped at any time.
MYOTONIA is the second of the two primary physiological responses to sexual intercourse. It is a temporary rigidity after muscular contraction just before and peri-orgasm. BP also rises, as does the respiratory rate.
In both sexes, detumescence is rapid. It is described as a "sense of well being" for both sexes.
In males, there is a refractory period that may run from minutes to hours with no further erection/orgasm. This increases as the male ages. In females, a refractory period does NOT exist. A female is capable of having multiple and successive orgasms with appropriate stimulation.
In the male, detumescence occurs in two phases: 1) partial disengorgement occurs due to contractions of orgasm (pumps blood out of erectile/genital tissues) and 2) a slower phase where genital blood flow returns to levels at the pre-arousal state.
If vasocongestion is not relieved in the male, PARTICULARLY if very high levels of arousal were reached, he may experience testicular aching and swelling of the vas deferens ("blue balls"). If vasocongestion does not occur in women, this leads to pelvic congestion and breast congestion with a secondary increase in size.
In adults, sexual response follows generally predictable patterns that have been documented by a number of researchers. However, there is some variation in the ways in which these patterns have been formalized. In this module, we will describe the sexual response cycle in five key stages, on the basis of a combination of models.
Although both men and women experience the same general stages of response, the amount of time needed to achieve each stage and the progression between stages may vary. In addition, psychological and emotional responses may vary greatly from person to person. Progression from one stage to the next is not inevitable: several of the stages can be achieved, lost, and regained many times without progression. The next page describes the five-stage sexual response cycle and examines each stage in more detail.
Before we present this information, it is important to note two important physiological factors that may influence sexual response:
There are five main stages to the sexual response cycle:
(Duration: anywhere from a moment to many years)
|Not applicable||Not applicable||Not applicable|
(Duration: anywhere from a few minutes to several hours)
|Heart rate and blood pressure increase, body muscles tense, sexual flush occurs, nipples become erect, genital and pelvic blood vessels become engorged, and involuntary and voluntary muscles contract.||The vagina
lengthens and widens, the clitoris swells and enlarges, breasts increase in
size, the labia swell and separate, the vagina becomes lubricated, and the
uterus rises slightly. Vaginal lubrication is the key indicator of sexual
Note: Women generally reach this stage more slowly than men do.
becomes erect, the scrotum thickens, and the testes rise closer to the body.
Erection of the penis is the key indicator of sexual excitement.
Note: Men generally reach this stage faster stage than women do.
(Duration: between 30 seconds and 3 minutes)
|Breathing rate, heart rate, and blood pressure further increase, sexual flush deepens, and muscle tension increases. There is a sense of impending orgasm.||The clitoris withdraws, the Bartholin’s glands lubricate, the areolae around nipples become larger, the labia continue to swell, the uterus tips to stand high in the abdomen, and the “orgasmic platform” develops (the lower vagina swells, narrows, and tightens).||The ridge of the glans penis becomes more prominent, the Cowper’s glands secrete preejaculatory fluid, and the testes rise closer to the body.|
(Duration: less than 1 minute)
|Heart rate, breathing, and blood pressure reach their peak, sexual flush spreads over the body, and there is a loss of muscle control (spasms).||The uterus,
vagina, anus, and muscles of the pelvic floor contract 5 to 12 times at
Note: Women can have orgasm, move back into plateau stage, and achieve another orgasm (called “multiple orgasms”).
|Ejaculation occurs (contractions of the ejaculatory duct in the prostate gland cause semen to be ejected through the urethra and penis), and the urethra, anus, and muscles of pelvic floor contract 3 to 6 times at 0.8-second intervals.|
(Duration: varies greatly)
|Heart rate and blood pressure dip below normal, returning to normal soon afterward; the whole body, including the palms of hands and soles of feet, sweats; there is a loss of muscle tension, increased relaxation, and drowsiness.||Blood vessels dilate to drain the pelvic tissues and decrease engorgement; the breasts and areolae decrease in size; nipples lose their erection; the clitoris resumes its prearousal position and shrinks slightly; the labia return to normal size and position; the vagina relaxes; the cervix opens to help semen travel up into the uterus—closing 20–30 minutes after orgasm; and the uterus lowers into the upper vagina (location of semen after male orgasm during penile–vaginal intercourse).||Nipples lose
their erection; the penis becomes softer and smaller; the scrotum relaxes,
and the testes drop farther away from the body. Depending on a number of
factors (including age), the refractory period in men, during which erection
cannot be achieved, may last anywhere from 5 minutes to 24 hours or more.
Our minds and bodies can respond sexually to a variety of stimuli—including sight, sound, smell, touch, taste, movement, fantasy, and memory. These stimuli can create sexual desire—a strong wanting for sexual stimulation (either by oneself or with another person) or sexual intimacy that may cause one to seek sexual satisfaction. Societal and cultural values influence the range of stimuli that provoke sexual desire, and ideals about the stimuli considered “sexual” or “attractive” can vary greatly between cultures and among subsets of a single culture. In addition, each individual reacts to sets of stimuli that are idiosyncratic—based on his or her own thoughts, feelings, and experiences.
Indications of Desire. Desire is a prelude to sexual excitement and sexual activity—it occurs in the mind rather than the body and may not progress to sexual excitement without further physical or mental stimulation. Desire may be communicated between potential sexual partners either verbally or through body language and behavior (for example, through “flirting”). This communication, which is shaped by sociocultural factors, may be subtle and easily misread. In different cultures, behaviors meant to communicate desire may vary greatly along gender lines; for example, in some cultures, women are expected not to express overt, verbal communication of their sexual desire, whereas such communication from men is expected.
Excitement is the body’s physical response to desire. (A person who manifests the physical indications of excitement is termed to be “aroused” or “excited.”) The progression from desire to excitement depends on a wide variety of factors—it may be brought on by sensory stimulation, thoughts, fantasy, or even the suggestion that desire may be reciprocated. For some persons (particularly for some adolescents), the excitement stage may be achieved with very little physical or mental stimulation, whereas for others, significant intimacy, physical stimulation, or fantasy may be required. It generally takes longer for women to achieve full arousal than for men to do so. Excitement may lead to intimacy and sexual activity, but this is not inevitable: for both sexes, initial physical excitement may be lost and regained many times without progression to the next stage.
Indications of Excitement. Excitement can be communicated between partners verbally, through body language, through behavior, or through any of the following body changes:
If physical or mental stimulation (especially stroking and rubbing of erogenous zones or sexual intercourse) continues during full arousal, the plateau stage may be achieved. This stage, the highest moment of sexual excitement before orgasm, may be achieved, lost, and regained several times without the occurrence of orgasm.
Indications of the Plateau Stage. The plateau stage can be communicated between partners verbally, through body language, through behavior, or through any of the following physiological changes:
Orgasm occurs at the peak of the plateau phase. At the moment of orgasm, the sexual tension that has been building throughout the body is released, and the body releases chemicals called endorphins, which cause a sense of well-being. Orgasm can be achieved through mental stimulation and fantasy alone, but more commonly is a result of direct physical stimulation or sexual intercourse (although many women report difficulty in achieving orgasm through vaginal intercourse alone). Women are capable of multiple orgasms (moving immediately from orgasm back into the plateau stage and to orgasm again), whereas men must pass through the resolution stage before another orgasm can be achieved.
Indications of Orgasm. The intensity of orgasm can vary among individuals and can vary for an individual from one sexual experience to another. Orgasm may involve intense spasm and loss of awareness, or it may be signaled by as little as a sigh or subtle relaxation. Orgasm can be communicated between partners verbally, through body language, through behavior, or through any of the following physiological changes:
Resolution is the period following orgasm, during which muscles relax and the body begins to return to its preexcitement state. Immediately following orgasm, men experience a refractory period, during which erection cannot be achieved (the duration of this period varies among individuals and increases with age). Women experience no refractory period—they can either enter the resolution stage or return to the excitement or plateau stage immediately following orgasm.
Indications of Resolution. Resolution can be communicated between partners verbally, through body language, through behavior, or through any of the following body changes:
Sexual Male Response Cycle
Female Sexual Response Cycle
The best and the highest sexual fulfillment and satisfaction can be reached if: (assuming both partners have the desire)
1- both partners reach orgasm almost at the same time, or
2- the female partner reaches orgasm before the male, or
3- there is stimulation of the G-spot (for more info about G-spot read this paper. Please note that its content does not mean it reflects my opinion) (the paper not included in the exam), or
4- long foreplay, ie, more than 30 minutes, or
5- the intercourse occurs during the ovulation period, or before/after menstruation ceased (except with dysmenorreaic women)
The Effect of Diseases and Drugs on Sexual Response
Short- and long-term use of recreational drugs (such as alcohol, marijuana, cocaine, amphetamines, and psychotropic drugs) can affect sexual function. For example, alcohol use can inhibit sexual function in both the short and the long run. Amphetamines can enhance sexual desire initially, but long-term use can lead to sexual dysfunction.
Chronic and debilitating diseases can also affect sexual desire and function. The medications used to manage many chronic conditions can also affect sexual response and performance; however, it is not always possible to predict which clients will experience these effects before the medication is prescribed.
The effect of drugs on sexual function is often underemphasized by health care providers and medical researchers, and there has been significantly more research into the effects of drugs on sexual function in men than in women. Providers rarely mention the sexual side effects of the drugs that they prescribe, sometimes out of the fear that clients will be reluctant to take the medications if they know about the sexual side effects in advance. There are a number of ways that medicines can interfere with sexual function or satisfaction. Some drugs cause drowsiness, lethargy, or depression; others interfere with the chemical messengers of the brain that are critical for sexual interest and function. Some drugs interfere with the ability to achieve orgasm, while others delay or prevent ejaculation.
There are number of ways that medications can interfere with sexual function and satisfaction. The following list, while not exhaustive, includes commonly prescribed drugs that have been implicated as affecting sexual functioning:
Note: Tranquilizers (such as Valium and Librium) and alcohol may increase sexual desire among inhibited individuals, but diminish both arousal and orgasm.
Dr Fora : MEMORIZE THE FIRST FIVE OF EACH GROUP
The following list, while not comprehensive, describes common conditions that affect sexual function. Other conditions that affect sexual function include cancer, thyroid disorder, Parkinson’s disease, chronic obstructive pulmonary disease, malnutrition, and alcoholism.
Sexual dysfunction is the persistent or recurrent inability to react emotionally or physically to sexual stimulation in a way expected of the average healthy person or according to one’s own standards of acceptable sexual response. Sexual dysfunction can occur during the desire, excitement, plateau, or orgasm stage of the sexual response cycle.
For example, one of the most common dysfunctions is inhibited arousal during the excitement stage. This presents as erectile dysfunction (impotence) in men or lack of lubrication in women. Occasional inhibited arousal is common and not dysfunctional; however, chronic inhibited arousal is a sexual dysfunction that can be caused by recreational drug use, certain medications, certain diseases, physical damage, or psychological factors. Any of the following factors can contribute to sexual dysfunction:
Common Sexual Dysfunctions
In diagnosis and history taking, it is important to remember that each dysfunction covered in this lecture can be lifelong (has always been present), acquired (has not always been present), situational (occurs in some situations and not others), or generalized (occurs regardless of the situation). The following list, while far from exhaustive, describes common sexual dysfunctions, their possible causes, and treatments.
Note: Sexual dysfunctions should be assessed objectively and managed according to the cause—not according to the status, orientation, or age of the affected client. The range of dysfunction encountered among adolescents, older clients, unmarried adults, homosexuals, and bisexuals is the same as that found among married heterosexual adults of reproductive age. If you feel unable to provide professional, impartial services to particular clients, refer the clients to another provider, if possible.
Sexual desire changes over the course of our lives, and occasional loss of desire in either sex is not uncommon. In ISD, however, there is persistent loss of desire that disrupts sexual relationships. It is characterized by diminished sexual attraction, decreased sexual activity, few or no sexual dreams or fantasies, and diminished attention to erotic material by one or both partners. ISD is the most common presenting sexual dysfunction in women and is less commonly reported in men. Female sexual arousal disorder (FSAD) is the name for persistent or recurrent inability to achieve or maintain an adequate lubrication-swelling response. (A woman with FSAD may or may not find enjoyment in physical contact.)
Causes of ISD:
Treatment of ISD:
Dyspareunia is a condition in women characterized by recurrent genital pain with sexual activity. Pain usually occurs with penetration but can occur during nonpenetrative genital stimulation as well. The pain can be superficial (at the vaginal opening) or deep inside the vagina. Repeated pain can create a negative cycle, leading to avoidance of sexual activity, lack of arousal, anorgasmia, and ISD. Symptoms may include burning, itching, stinging, or inflammation in any area of the perineum.
Causes of dyspareunia:
Treatment of dyspareunia:
Vaginismus is a condition in women characterized by difficulty in achieving penetration or discomfort during penetration due to involuntary contractions of vaginal muscles. Some women’s symptoms are so severe that they avoid any sexual contact; others may have satisfying sexual experiences through extensive foreplay leading to orgasm without penetration.
Causes of vaginismus:
Treatment of vaginismus:
Anorgasmia is a condition in women characterized by a persistent or recurrent delay in or absence of orgasm following a normal sexual excitement or plateau stage. Affected women may have strong sexual desire, adequate arousal during the excitement stage, and pleasure with vaginal penetration but are unable to experience orgasm, even with adequate stimulation. (Note: Women are often misdiagnosed as anorgasmic if they are not able to experience an orgasm through penile-vaginal intercourse. A woman is not anorgasmic if she can achieve orgasm through means other than penile-vaginal stimulation.)
Causes of anorgasmia:
Treatment of anorgasmia:
Premature ejaculation is a condition in men characterized by persistent or recurrent ejaculation with minimal sexual stimulation before, on, or shortly after penetration and before the person wishes it. PE occurs when a man is unable to exert reasonable voluntary control of his ejaculatory response and is unaware of erotic sensations leading to the “point of inevitability” and ejaculation. PE is most common among younger men and men with limited sexual experience. The condition is often associated with performance anxiety.
Causes of PE:
Treatment of PE:
Male orgasmic disorder is persistent or recurrent involuntary delay in orgasm and ejaculation or the inability of the man to have orgasm. (Note: This is sometimes confused with retrograde ejaculation—a condition in which the man ejaculates into his bladder instead of out through the urethra. Retrograde ejaculation is common in gay men and may be related to fears of infection believed to be brought on by “safer sex” campaigns.)
Causes and treatment of male orgasmic disorder:
ED (also known as impotence) is the persistent or recurrent inability in men to attain an erection or to maintain an erection until completion of sexual activity. (Note: Occasional inability to achieve erection may cause undue stress and result in performance anxiety, which affects future functioning and creates a cycle of impotence. Occasional impotence is common; this is usually situational and is not considered dysfunctional.) Erectile dysfunction, usually of an organic type, is being seen increasingly in those with late stage HIV. It is not yet clear whether ED is an effect of the virus or of the antiviral drugs used to treat infection.
Causes of ED:
Treatment of ED:
Infertility may be a contributing cause of sexual dysfunction. For example, sexual function may be affected by infertility when investigations and treatments alter a couple’s mode of sexual relations. Alternatively, a man may feel excessive pressure to perform, which negatively affects his erectile or ejaculatory ability when the couple tries to conceive.
Both men and women can develop arousal difficulties because of the associated anxiety and stress of performing. In addition, some partners may feel their self-worth compromised by being sought only when conception is more likely. These stresses usually diminish the pleasurable aspect of sexual expression and focus sex solely on reproduction. Erectile failure during sexual intercourse due to pressure to perform may begin a vicious cycle of fear of failure, with anxiety leading to further failures. Consequently, men may experience loss of desire and decreased sexual activity, erectile problems, premature ejaculation, or delayed ejaculation. Women may experience loss of desire, vaginismus, dyspareunia, or anorgasmia.
When clients first present with infertility, providers should investigate the possibility of retrograde ejaculation (ejaculation into the male urinary bladder), as well as the possibility that the client does not fully understand reproductive functioning and is engaging in sexual activities that are not associated with pregnancy—for example, deposit of sperm into locations other than the vagina (e.g., rectum).
Pregnancy stimulates tremendous changes within women and between couples. The changes may be a combination of hormonal and physical changes, beliefs about the roles of motherhood and fatherhood, accepted myths or taboos about sexual activity during pregnancy, or feeling of unattractiveness.
Fears that sex will cause miscarriage, premature labor, or fetal damage are very common. However, studies have shown that there is no significant increase of fetal problems, miscarriage, or premature labor in women who continue to be sexually active throughout pregnancy. It should be noted that during orgasm, the uterus contracts, and some women experience painful contractions after orgasm; however, this does not lead to premature delivery.
Sexual difficulties may also occur after delivery as a result of episiotomy or vaginal lacerations, discomfort, breastfeeding, fatigue, sleep deprivation, or shifted focus from the couple’s needs to that of the infant.
When a pregnant woman is in danger of going into premature labor, any sexual activities that would cause uterine contractions (e.g., nipple stimulation or activities leading to orgasm) should be avoided.
For more info (not included in exam):
Circumscion (male and female) in view of Islam. There are lots of research against male circumscision because they claim that it prevents sexual satisfaction.
Dr Mahmoud Ahmad Fora
Last Updated Mar 25, 2006