As a result of sexual intercourse, male sex cells (spermatozoa) enter the female reproductive tract. In the process of coitus, the man enters the erect penis into the woman's vagina. Sexual arousal leads to the emergence of seminal fluid from the testicles and out through the urethra during ejaculation.
Stages of excitement
Sexual arousal goes through several stages. In each of these stages in the body there are certain changes. After the emergence of desire, the body of a man and a woman enters into a series of successive phases:
• Excitation;
• Plateau phase;
• orgasm;
• discharge.
Manifestations of sexual arousal in men and women vary significantly, as well as among members of the same sex. However, orgasm is the culmination of sexual intercourse for both sides.
Psychological aspects
Ejaculation of semen during male orgasm is a necessary condition for fertilization. It is believed that the female orgasm increases the likelihood of conception. Achieving orgasm is the main goal of sexual intercourse. For many, it is the desire to experience the pleasure of orgasm that serves as the motivating motive for intimate relationships.
Excitation
Forcing a man there is a sharp increase in blood flow in the genital area, which leads to an erection of the penis. In addition, the blood pressure, pulse and respiration rate increase.
Plateau phase
The penis becomes more and more tense, and its head can be moistened with the secret of bulbourstrual glands (located at the base of the penis). The testicles are shortened and pulled to the perineum. In the course of several contractions, the spermatozoa move from the epididymis to the terminal part of the vas deferens. Here they mix with the secretion of the prostate gland and seminal vesicles with the formation of seminal fluid. At this point, the man experiences a feeling of "inevitability of ejaculation." This means that ejaculation will occur even when the stimulation of the penis ceases.
Orgasm
After orgasm, the penis and testicles return to their normal state. Breathing and palpitation slow down, blood pressure decreases. It is believed that the female orgasm promotes the passage of sperm into the uterine cavity in the process of sexual intercourse, thereby increasing the likelihood of fertilization. However, many women never experience orgasms during coitus, but nevertheless are able to become pregnant.
Excitation
During the excitation phase, a swelling of the clitoris and the walls of the vagina is observed in the woman. Large labia acquire a darker shade, and the labia minorae flatten and somewhat diverge. One of the first signs of sexual arousal in a woman is the moistening of the vaginal opening as a result of stimulation of the secretory cells of the vaginal mucosa. Slime moistens its walls, preparing for penetration of the penis. There is also a slight engorgement of the mammary glands and tension of the nipples. Areola nipple also slightly swells and becomes darker. Blood pressure, respiratory rate and muscle tone increase. The excitation passes to the plateau phase or gradually fades away.
Plateau
If the excitation continues, the woman enters the plateau phase, which is characterized by increased blood flow in the genital area. The lower part of the vagina narrows and tightens around the penis. The upper part of the vagina, on the contrary, slightly widens, and the uterus slightly lifts above the cavity of the pelvis, which also increases the volume of the vagina and creates a reservoir for sperm reception. During this phase, the labia minor becomes darker, and the clitoris is shortened and drawn into the clitoral hood (analogous to the foreskin). It is possible to separate a few drops of secretion of the vestibular glands in the vestibule of the vagina. With the continuation of stimulation, this phase can end with orgasm - the third and the shortest period. Female orgasm can be very intense, but rarely lasts more than 15 seconds. It begins with rhythmic contractions of the lower part of the vagina. The first contractions occur at an interval of 0.8 seconds, as in the case of male orgasm. Intervals are gradually increasing. It is possible that these contractions contribute to the advancement of semen into the uterus and uterine (fallopian) tubes. The wave of contractions extends through the walls of the vagina to the very womb. The muscles of the pelvis and perineum (the spaces between the anus and the vagina) are also contracted, as well as the muscles around the opening of the urethra and rectum. Depending on the strength of orgasm, a woman experiences 5 to 15 waves of contractions. Muscles of the back and legs can be subjected to involuntary contractions, causing extension of the back and flexion of the fingers. The heart rate can reach 180 beats per minute, and breathing - 40 per minute. The blood pressure rises, the pupils and nostrils widen. At the time of orgasm, a woman often breathes or holds her breath.
Discharge
At the end of orgasm, the discharge phase begins. The mammary glands return to their normal state, the muscles of the body relax, breathing and palpitation come back to normal. After ejaculation, a man has a refractory period, during which he is not capable of sexual arousal. This latent period can last from two minutes to several hours. Women have a refractory period, some are capable of experiencing multiple orgasms.