Post Date December, 03 2023
When a man excites the cerebral cortex due to the stimulation of hearing, vision, smell, thinking, imagination, etc. related to sexual content, and transmits it through the erectile center of the thoracolumbar segment of the spinal cord, which acts on the cavernous body of the penis, it will expand the arterial vessels, and a large amount of blood will flow into the cavernous body of the penis; When the veins constrict and the amount of blood flowing out of the cavernous body decreases, the blood will be fully trapped in the abundant blood vessels and blood sinuses in the cavernous body, making the penis quickly produce psychological erection.
On the contrary, when the artery constricts, the blood flowing into the cavernous body of the penis decreases; When the veins dilate and the rich blood flow trapped in the sponge rapidly returns, the penis will become weak again.
When the external genitalia is stimulated by direct touch, walking friction and other local stimuli, or by internal stimulation of rectum and bladder, it can cause reflex erection, which is achieved by stimulating the lower erectile center of sacral cord in the spinal cord to stimulate its sexual excitement. Penile erection is natural. Male fetuses can erect in the womb. When a little boy urinates after birth, his erection may become hard. Sometimes lying there and urinating can make the urine spray straight into the adult's face like spring water, which often brings unexpected laughter and joy to the parents who are changing diapers, but the erection at this time does not have any meaning of "sex".
Any stimulation of the genitalia itself can cause reflex erections, which play a regulatory role through the pudendal nerve and sacral cord erection center.
Psychological and physiological stimulation can not only play a role alone, but also influence each other and participate in sexual activities together. For example, when the spinal cord injury occurs above the thoracolumbar region, the patient can only have an erection when the genitals receive physical stimulation, and the ability of psychological erection disappears. When motor neuron injury occurs at the level below the thoracolumbar region, stimulation of the genitals cannot cause erections, while 24 to 57% of patients still have psychological erections, that is, psychological stimulation can be transmitted through the thoracolumbar pathway. When the spinal cord injury occurs at the waist 2 to sacrum 1, both psychological and reflex erections exist, but the two cannot be coordinated. It is impossible to achieve ejaculation climax through genital stimulation.
In addition to psychological erections and reflex erections, there is also a kind of nocturnal erections in normal men. Men's sleep is always in the alternation of fast eye movement sleep and slow eye movement sleep, and they also experience the physiological process of erection-flaccidity-re-erection-flaccidity. This is called penis nocturnal erections in medicine, which is the normal physiological process of healthy men. Generally speaking, men will have 4 to 6 erections every night, 20 to 40 minutes each time, with a total of two and a half hours. This is because the brain always suppresses the occurrence of sexual reactions in the daytime, otherwise men will inevitably encounter awkward situations from time to time, but after sleeping soundly, this inhibition function of the brain will disappear, and the penis will spontaneously have an erection reaction, which is completely normal, and need not worry.
The time, frequency and hardness of erection at night will decrease with the increase of age, and it is the strongest from adolescence to about 20 years old. Whether it is psychological or reflex erection, the penis will soon return to normal after the external stimulation is removed. Erections at night are no exception. After erecting for a period of time, the penis will certainly weaken automatically, because if the blood is left in the sponge for a long time, the blood will be anoxic and accumulate a large amount of metabolic waste, which is harmful to the tissue, and necrosis will occur in serious cases.
This is the case with an abnormal erection of the penis. The patient shows that the penis is continuously swollen, hard, painful, and grayish in color for more than 4 to 6 hours. This is an emergency of urology and needs to be treated in the hospital as soon as possible. So the penis is not erect all night, but must be relaxed and relaxed. Early morning erection is a clinically significant physiological phenomenon. Some doctors have specially studied this phenomenon and found that men's erections will weaken or disappear in the early morning during their illness; After the body recovers, the erection will also recover in the morning. Therefore, the phenomenon of early morning erection can be used as a reference indicator of male health. The presence or absence of erections in the morning can also be used as a reference index to judge the status of men's sexual function.
