Erection and ejaculation

A necessary condition for sexual intercourse in men is erection (from the Latin "eligere" - raise) of the penis. It is based on vascular reflex, resulting in the volume of the body, increasing its volume (3-4 times) and temperature increase. The mechanism of erection is that nerve impulses that arise when sexual excitation, causing a sharp expansion and relaxation tone of the walls of arteries of the penis and enhanced the inflow of arterial blood. The blood flow through the cavernous bodies increases by 8-10 times. At the same time a decline of the transverse muscle of perineum and prostate. In erection participate sciatic-cavernous and bulbous-cavernous muscle that are Contracting, squeezing the base of the penis. Under the influence of these muscles and crowded blood caverns are squeezed veins carrying blood from forming a basis penile cavernous spaces. As a consequence reverse the outflow of blood is inhibited, the cavernous space of a member overflowing with blood and swell. This causes erection. This cavernous tissue of the urethra and head less tense than cavernous bodies of the member; this creates favorable conditions for the passage of semen through the urethra.
However, the complete cessation of blood circulation in the penis during erection does not occur, as evidenced by elevated temperature erect member; circulation during erection only slowed, but not stopped. Blood flow is balanced by a corresponding outflow.
Together with the cavernous bodies bit swells and seed mound, squeezing both holes semyavynosyaschih ducts. At this time several tapering prostate urethra and dramatically shrinks internal gallbladder sphincter (the muscle bagasse), pregrada message urethra with the cavity of the bladder. Thanks to this part of the canal, lying in front of holes semyavynosyaschih ducts, becomes passable only for the sperm, and the expiration of urine stops. This explains the fact that the busy penis urinate almost impossible. This occurs during sexual arousal, when erections and ejaculations, when many in the blood hormone, which involuntarily tones gallbladder pulp and relaxes the muscle of the bladder.
Cerebrospinal center of erection excited under the influence of hormones sexual glands, impulses from the brain-cortex, and the impulses of the prostate, seminal vesicles and erogenous zones (especially from the head of the penis). Irritability nerve cells of the center of erection constantly fluctuating and changing.
To have an erection lead and anger coming from different parts of the urogenital system, for example, in acute inflammation of the urethra, prostate cancer, gallbladder stones, overstuffed seminal vesicles, and at the irritation of the bladder neck, when he is overwhelmed with urine (morning erection), etc., But these spontaneous erections, that is, spontaneous, they are passive, as if blind, not directed to a specific purpose. Physiologically and biologically appropriate erections occur only under certain conditions, in the presence of sexual desire and sexual excitation of the cerebral cortex.
Now, thanks very careful experimental studies and in-depth studies conducted by a number of scientists, in particular American authors Century by Century Masters and Johnson, we are enriched by the knowledge of the physiological reactions that occur during sexual arousal during sexual intercourse men and women. This applies both to the reactions of the sexual apparatus and physiological responses of other body systems.
If enough arousal and attraction of erection to happen and sexual apparatus women. All the sex channel women, including the uterus is filled with blood, the walls of the vagina significantly increase in volume. Increases in size and clitoris, but due to small size is almost invisible. Chubby women never reaches such an extent, feces in men. She can do it and not to appear or occur only during sexual intercourse.
During erection at strong sexual arousal in men, the urethra, and the woman on the vulva appear stringy mucus. Its alkaline reaction they create in the urethra men favorable conditions for the life of sperm, making the same slimy mucous channel, facilitate the removal of the seed.
Ejaculation (from the Latin "ejaculatio" - throwing, eruption) - also the reflex act. The excitatory impulses to the center ejaculation come from the penis, seed mound, and vials of the VAS deferens, seminal vesicles and prostate. Without sufficient accumulation secret (secretory voltage) in these latter bodies and seminal fluid in ampoules VAS deferens ejaculation does not occur, sometimes with overly frequent sex and age. Serial number frictions (friction to ejaculation) creates a physiological process of combining irritation to the level, when the threshold of excitability of Central ejaculation.
Anxiety ejaculatory center are under the influence of neuro-psychological and hormonal and direct stimulatory or inhibitory effects on the part of the cerebral cortex. The impulses which complete ejaculatory reflex, going from the centre ejaculation to smooth muscle ejaculatory tract, prostate gland, seminal vesicles, urethra, and to the muscles of the perineum. Abbreviations powerful muscle walls VAS duct, it ampoules and seminal vesicles seed goes through semyavynosyaschih ducts in the back of the mouth of the urethra, where it is mixed with the juice of the prostate. Moreover, the ductus deferens during ejaculation greatly shortened (from the reduction)and after ejaculation again he stretched to its original length. During ejaculation primarily emptied ampoule. Prostate her powerful muscles is also involved in ejaculation.
Promotion of seed on toward the opening of the urethra occurs with spasmodic contractions of smooth muscle fibers of the walls of the urethra, striated external urethral sphincter and muscles of cavernous bodies of the penis. Quickly and rhythmically, one after another consecutive cuts in all of these muscles covering the rear part of the urethra and cause jerky discarding seed from the urethra. Stop by willpower started ejaculation impossible - it is an involuntary reflex.
Semen erupt under the pressure created by the reduction of these muscle groups, with considerable force, which in the initial phase in young healthy men can reach up to 1 m per second with a cast seed to a distance of 20-30 cm Force of ejaculation and the associated orgasm depends on the tone of these muscles. In old age and ageing an ejaculation occurs just a few inches from the external opening of the urethra or even just flows out. Power orgasmic sensations while also decreasing.
The reflex erection and ejaculation, consistently developing one after the other during sexual intercourse are independent from each other to such an extent that may occur and one without the other. Under certain conditions it is possible to highlight the seed without erection and reverse the cases when an erection is not accompanied by the expulsion of the seed. However, in the process of normal sexual activity both reflex interrelated. Erectile and ejaculatory reflexes are Executive in nature, they are determined by the impulses, coming from the highest courts of the nervous system and erogenous zones.
The possibility of erection and ejaculation marks the sexual maturity of the person, his ability to produce offspring.