What is meant by sexual arousal? - Chapter 8

Sexual expression contributes to an overall good mental health. Understanding sexual arousal is also important in understanding sexual dysfunctions.

What is the sexual response cycle?

Sexual response commonly happens in three stages: excitement, orgasm and resolution. The physiological mechanisms are myotonia and vasocongestion. Vasocongestion takes place when a major deal of blood flows in regional blood vessels, such as the genitals. It is a result of dilation of these blood vessels. Myotonia is the contraction of the muscles throughout the body, so not only in the genitals.

Excitement

The excitement phase is the start of sexual arousal. Vasocongestion causes the erection in males, it happens when the corpora cavernosa and corpus spongiosum fill with blood. Factors such as alcohol, fatigue and age can slow down this process. Several neurotransmitters are involved in this process, for instance, Viagra works on the nitric oxide neurotransmitter. To reverse the erection, the neurotransmitters epinephrine and norepinephrine are involved. In women, a critical sexual response is lubrication of the vagina. This is also a result of vasocongestion. The blood flow through the walls of the vagina causes the capillaries to dilate. Fluid can then seep trough the membranes of the vaginal walls. It does not happen as fast after presentation of arousing sexual stimulation as it does with men. Female response to these stimuli is also affected by age, alcohol intake and fatigue.

When the woman gets closer to an orgasm, the orgasmic platform forms. This is the narrowing of the muscle around the entrance of the vagina. When a woman is excited, the tip of the clitoris is swollen and is harder than normally. Relaxation of the muscle that surrounds the arteries allows for a great blood flow to the genitals. Nitric oxide is also the main neurotransmitter involved. One effect from myotonia is that the nipples erect, this is both present for males and females. During arousal the inner lips of the vaginal walls swell and open. The opening of the vagina is also called the ballooning response. This helps the entrance of the penis. Later in the phase of excitement, the two processes of myotonia and vasocongestion built up to the orgasm.

Orgasm

The orgasm in males exists from contractions of the pelvic organs. In the preliminary stage of the orgasm the prostate, seminal vesicles contract and the vas contract. This drives the ejaculate into a bulb at the base of the urethra. The sensation is called ejaculatory inevitability (Masters & Johnson, 1966). It resembles a feeling that ejaculation is about to happen and cannot be stopped. In the second stage, the urethral bulb that was formed in the first stage contract rhythmically and forces the semen to go trough the tip of the penis. Blood, pulse and heart rate increase during the orgasm. Muscles contract throughout the body, contractions of hand and feet are called carpopedal spasms.

In females the uterus contracts rhythmically and muscles around the anus may also contract. The sensation begins around the clitoris and spreads to the rest of the pelvis. The sensation for men and women is very alike. Faking an orgasm follows a sexual script in which the woman should orgasm first. Women fake due to the sake of their men’s feelings, which is not a good thing because it prevents a partner from getting a valid sexual response. There is one way to tell if a woman is experiencing an orgasm, which is by measuring the sudden increase in pulse rate.

Resolution

The orgasm is typically followed by the resolution phase. The body then returns to an unaroused state and processes that build up during excitement are reversed. Resolution is characterised in the shrinking of swelled organs and a decrease in blood pressure, heart rate and breathing rate. The resolution phase in men is followed by a refractory period where the men cannot be sexually aroused. This can last from a couple of minutes to twenty-four hours.

How does the female orgasm work?

Many people believe the woman can experience two types of orgasms, the clitoral and the vaginal orgasm. These types refer to the area of stimulation. However, according to Masters and Johnson (1966) there is no difference. The area of stimulation does not cause any different response, some women are even able to get an orgasm through stimulation of the breasts. However, the experience of an orgasm differs based upon the area of stimulation. The stimulation of the clitoris is almost always involved in the orgasm and is also stimulated during vaginal sex. A shorter distance between the clitoris and the vaginal opening results in a higher change of orgasm during vaginal sex. Females do not have a refractory period that men have. Women can this have multiple orgasms, having separate orgasms occurring in a short period of time. It is more likely to happen with mouth or hand stimulation than from vaginal intercourse.

What are other models of sexual response?

One criticism of the stated model above is that it neglects the cognitive -and subjective influences on sexual response. Therefore, other models were proposed. These include the Kaplan triphasic model and the sexual excitation-inhibition model.

Kaplan’s triphasic model exists of the elements of sexual desire, vasocongestion and contractions of the muscles during the orgasm. Both the contractions and vasocongestion are physiological, however sexual desire is psychological. It can happen prior to sexual arousal or spontaneously. There is empirical evidence for the approach: whereas the parasympathetic system is responsible for vasocongestion, the sympathetic system is responsible for ejaculation. Another empirical support was found in the decrease of orgasm frequency with age. Lastly, the sexual disturbance caused by impairment of vasocongestion is an erection deficit, whereas problems with (premature) ejaculation are caused by disturbance in orgasm response.

The sexual excitation-inhibition model or dual control model of sexual response states that there are two processes responsible for sexual response:

1. Excitation, the response of arousal to sexual stimuli

2. Inhibition, inhibiting sexual arousal

The leading criticism on the physiological model of Masters and Johnson (1966) is that the explanation of sexual arousal is ignoring the emotional component. Positive emotions have a positive effect on sexual arousal. Also, negative emotions have a positive effect on sexual arousal. The experience of negative emotions caused an increase in sexual arousing thoughts. According to researchers generalised arousal is caused by negative emotions which results in a higher susceptibility to sexual stimuli.

What are the neural and hormonal bases of arousal?

Besides physiological and emotional influences of arousal, hormones can influence the sexual response cycle.

The brain, the spinal cord, and sex

• Spinal reflexes control erection and ejaculation. The receptors are sensory neurons that transmit and detect sexual stimuli to the brain. Then, transmitters receive the stimuli and the effectors respond.

• Erection works trough the erection centre which is the lowest part of the spinal cord. This causes a reflex trough the spinal cord to permit blood flow into the genitals.

• Ejaculation is alike erection, but there are two centres. The ejaculation reflex sends a message to the ejaculation centre which is situated in the lumbar portion of the spinal cord. Retrograde ejaculation is when the ejaculate ends up in the bladder. A dry orgasm is the result.

• Reflexes in women are less researched, information transfers trough the dorsal nerve of the clitoris to the sacral portion of the spinal cord. The G-spot or Grӓfenberg spot or female prostate/skene’s glands is situated on the top side of the vagina. It produces a uterine orgasm which are deeper uterine contractions than with a vulvar orgasm.

Brain control of sexual response

Sexual response is highly psychological and environmental factors may affect one’s sexuality. This happens trough brain -and spinal cord interactions. According to one scientist, the brain is the most important organ in sex.

• The anticipatory phase is when the sexual interest network is stimulated by arousing content. The role is probably to recognise sexual opportunity. The sexual arousal network is situated in different regions of the brain.

• The consummatory phase happens during sexual activity. Stimulation of the genitals corresponds to activity in the motor cortex.

• The orgasm causes a decrease in activity of the prefrontal cortex and increased activity in the orbitofrontal cortex.

• The resolution and post-orgasmic refractory period correspond to the de-arousal neural network and is observed in the septal area, amygdala and temporal lobe.

• Neurochemical influences on sexual response are experienced throughout the sexual response cycle. Dopamine, norepinephrine and oxytocin are released and related to sexual arousal.

What is the influence of hormones on sex?

Hormones interact with the nervous system in generating sexual responses.

• Organising effects are the consequences of sex hormones that cause permanent changes in the reproductive system and the brain.

• Activating effects of hormones are aggressive and sexual behaviours, especially in adulthood.

• Testosterone positively affects libido and desire. In women, androgens are related to sexual desire.

Could castration be used to reduce sexually violent crimes?

Physical castration is the process of removing the testes surgically. This is also known as bilateral orchiectomy. Chemical castration is the administration of a drug that reduces the testosterone level to reduce sexual desire and libido. The effects of castration are not completely predictable. Rapist cannot always be restrained by lowering their testosterone levels, there is more than sexual behaviour involved. It is an aggressive crime that is expressed trough sex. Castration might reduce the chance of rape, but psychotherapy should always be included in the treatment.

What are pheromones?

Hormones and pheromones are alike, pheromones are secreted outside of the human body. Pheromones can be described as sex attractants. They play an important role in human sexuality.

What are the existing sexual techniques?

Erogenous zones are parts of the body that are sexually sensitive. People differ in their erogenous zones. One-person sex or autoeroticism is when a person produces his own sexual stimulation. There are may examples of one-person sex:

• Masturbation is self-stimulation either with the hand or an object. It is very common sexual behaviour and s used in both males and females.

• Sexual fantasy is the mental imagery that includes sexual arousal. It is experienced by both men and women. People can fantasize about very different things, such as sex in unusual or romantic places. Men are more likely to fantasize about being masturbated by an unknown person. Images in sexual fantasies can come from the media, dreams or stories. They represent a fusion of body, emotion and mind.

• Vibrators and other sex toys can be used for masturbation or by couples. A dildo is a plastic or rubber cylinder in the shape of a penis. A vibrator can be shaped like a penis, but many of them are not. They use some form of an electric outlet. Body oils are also popular for sexual pleasure, they heighten erotic feelings.

For two-person sex there are a lot of behaviours and actions imaginable. It is important to note that the image of two-person sex often reflects heteronormativity. This -and other assumptions can put restraints on human sexuality. The techniques described below attempt to avoid assumptions about two-person sex.

• Kissing is done in almost all cultures and the variation that is used depends on personal preference.

• Touching is essential to sexual pleasure, the regions that are sensitive vary from one person to another.

• Other senses, such as smell, and hearing can also contribute to sexual pleasure.

• Fantasy can heighten the experience without violating the agreement to be faithful to another person.

• There are many positions of intercourse, the most common one is coitus, which is the insertion of the penis into the vagina. There are a few basic positions that can have infinite alterations and extensions. The missionary or man-on-top position is the most frequent. This is the best position for ensuring conception. The woman-on-top position provides a lot of clitoral stimulation which the woman can control. The rear-entry position is where the man is facing the woman’s back. It can also happen in side-to-side position which is good for the pregnant and obese.

• Mouth-genital stimulation increased in popularity over the last few years. There are two variations. Cunnilingus is mouth-stimulation of the woman’s genitals. Fellatio is the stimulation of a men’s penis. The equal occurrence of cunnilingus and fellatio is called sixty-nining.

• Anal intercourse is when the penis is inserted into the rectum of the partner. Sometimes referred to as sodomy or Greek-style. A variation is anilingus in which the tongue and the mouth stimulate the anus.

• Techniques of lesbians and gays are like heterosexual intercourse techniques, except for coitus. Gay men can engage in interfemoral intercourse in which the penis of the man moves between the thighs of his partner. Lesbians can engage in tribadism where one partner is lying on top of the other making movements to stimulate the genitals. Another option is the use of a dildo.

• Cybersex is considered a new sexual space for intimacy, fantasy and action.

What are aphrodisiacs and anaphrodisiacs?

An aphrodisiac is a substance used to increase sexual desire. An anaphrodisiac is a substance that diminishes sexual desire.

What are forms of exceptional sex?

There are characteristics that have been described that make the difference between good and great sex. These are the following:

1. Both persons should be equally present and focused.

2. A deep connection between the partners engaging in sex should be present.

3. There should be deep -or emotional intimacy.

4. Extraordinary communication contributes to a total sharing between partners.

5. Both persons should feel free of inhibitions and unselfconscious.

6. Interpersonal risk-taking, fun and exploration are central subjects of great sex adventures.