How An Erection Works
An erection is quite an impressive function. It is about the only marvel of the human body that can be observed regularly without the help of any device. This may look like a rather simple and straightforward function, but it really is not. Regardless of whether it is the penis or the clitoris, the process is very much the same and just as complex. This is because both of these functions are controlled by either the central nervous system or the autonomic nervous system. It simply depends upon what type of stimulation is encountered.
Usually men's stimulation is based upon visual, auditory, olfactory, imagined or tactile stimuli. These tell the cerebral cortex to start the erection process. The erectile centers are located in the lumbar and sacral regions of a person's spinal cord. They tell the nerves in the pubic area to start releasing nitric oxide, which is a chemical compound that is widely used by all mammals who need to transmit information from one cell to another.
Once the nitric oxide is released, the arteries that supply blood to the penis become dilated, thus allowing a lot more blood to enter into the penis. This blood goes into the Corpora Cavernosa, which are the 2 sponge-like tissues that have been designed to expand in size while holding as much blood as it can. The Corpus Spongiosum is the tubular structure that is located just below the Corpora Cavernosa, which is what both urine and semen pass through. This also becomes slightly engorged with blood. However, it does not become nearly as engorged as the Corpora Cavernosa.
Just as soon as there is enough blood in the penis, the arteries will contract so that the penis can return to its normal flow of blood. Herein the blood inside of the penis is prevented from leaving the area. This same system is also used for mechanical stimulation of the penis whenever external stimuli are not available. The whole process is taken care of by the autonomic nervous system (ANS). There is only minimal input from the central nervous system. Once the stimulation ends, the ANS will make the arteries constrict so that the blood is forced out of the penis.
It is important to note that the cerebral cortex is not involved in every type of stimulation that causes erection. However, it can put an end to any erection if it feels as though this is what needs to be done. This is why it is important to avoid anything that kills the mood or turns them off.