How Does The Erection Mechanism Works?
The erection process is most commonly initiated by stimulation - based on visual, auditory, tactile, or even imagined stimuli - that activate the cerebral cortex to begin erection. The nerves in the pubic area to start releasing nitric oxide is told by the erectile centers located in the lumbar and sacral regions of the spinal cord. Nitric oxide is a chemical compound found in mammals and used to transfer information cell to cell.
The release of the nitric oxide allows greater dilation of the arteries which supply the penis with blood, which results in more blood to maintain an erection. The two sponge-like tissues that are designed to expand in size and hold as much blood as possible and the blood goes into the Corpora Cavernosa.
The Corpus Spongiosum, the tubular structure located just below the Corpora Cavernosa through which urine and semen pass, also becomes slightly engorged with blood, but not nearly as much as the Corpora Cavernosa.
Once enough blood fills the penis, the arteries contract to prevent the blood from just leaving the tissue. The identical procedure is utilized in the case of mechanical stimulation of the penis and when exernal stimulation is missing. The entire process is handled by the autonomic nervous system (ANS) with minimal input from the central nervous system. The ANS causes the arteries to constrict, thus forcing blood from the penis once stimulation ceases.
Although the cerebral cortex is not involved in every type of stimulation that causes erection, it, nevertheless, can put an end to any erection if it judges that the situation requires such action. For example a thought turned to baseball scores can end an erection. This is a reason why it is important for men and women to avoid things that have the ability to kill the mood and, thus, turn them off.