Generally speaking, the duration of male excitement is mainly through continuous stimulation of the penis and glans, making sexual stimulation more and more intense. At this point, the stimulation signal located in the central nervous system of the immortal spinal cord will rise upwards through the spinal cord, causing the ejaculatory center of the lumbar spinal cord to have a reflex effect, resulting in orgasm (ejaculation).
Therefore, male orgasm ends with a single ejaculation, strong muscle contractions of 3-8 times, and a maximum of 3-10 seconds. If the ejaculation action of 3-10 seconds is decomposed, it can be divided into two stages in detail. The first stage is that the lumbar spinal cord ejaculatory center that triggers reflex reaction sends instructions to the smooth muscle on the wall of accessory sex organs (accessory testes, seminal vesicles, prostate), so that the muscles contract. At this time, prostatic fluid (semen) will be ejected to the rear of the urethra.
Then, the sperm and testicular secretion from the accessory testes and seminal vesicles are transported to the spermatic ducts, which is the beginning of the reflex effect of coitus interruptus. The above are all functions of the autonomic nervous system. When we reach this level, we have not yet experienced any pleasure, but are simply trapped in a situation where 'once activated, it is inevitable'.
If we continue to strengthen the stimulation, we will enter the second stage. At this point, the muscles located at the base of the penis contract simultaneously with the muscles hanging from the testicles (testicular lifting muscles). Due to the strong propulsion force, semen will be continuously ejaculated from the urethral opening of the penis in an instant. When semen is ejaculated, the urethra expands by 2-3 times. Therefore, the bladder sphincter is blocked and cannot urinate.
Usually, there are 7-8 episodes of spasms and contractions in humans every 0.8 seconds, but as age increases, it gradually decreases to 3-5 episodes. During ejaculation, if the surrounding muscles produced contract simultaneously with the muscles from the buttocks to the lower thighs, it can simply lead men to the pinnacle of sexual pleasure.
In short, male orgasmic ejaculation involves the entire forward contraction of the urethra inside the penis. At first, it was once every 0.8 seconds, but after three or four times, it weakened. At this point, the testicles, vas deferens, epididymis, seminal vesicles, and prostate gland also contract, and ejaculation occurs.
Ejaculation can be divided into two stages. The first stage is the contraction and forward discharge of the aforementioned organs, allowing semen to enter the urethral area of the prostate. At this time, the sphincter at the outlet of the bladder is locked to prevent semen from flowing back into the bladder. The second stage is when semen is discharged forward to the urethral opening. Therefore, ejaculation is an involuntary reaction that is "inevitable once initiated" and cannot be stopped.
(Intern Editor: Cai Junyi)