When a man is sexually excited the brain sends chemical signal to nerves in his penis. Those nerves cause blood vessels of the penis to release the chemical. This chemical then triggers a series of events that causes too large chamber of the penis to fill with blood. As the chambers fill up, it blocks the veins that let blood flow out of the penis and a man is able to get and maintain an erection.
Erection begins with the mental stimulation or sensory or both. Impulses sent from the brain and local nerves causes the muscles of the corpora cavernosa to relax and allowing the blood to flow in and fill the spaces. The blood then creates pressure on corpora cavernosa and makes the penis to expand. Tunica albuginea helps to trap the blood in the corpora cavernosa thereby sustaining erection. Erectile Dysfunction is one of the most common sexual problems that affect around half of the men over 40 at same point.
For instance, physical health problems can cause psychological distress that can have an additional effect on erection problems. Several conditions prevent sufficient blood getting into penis and so caused ED. There can also be problems with keeping the blood within the penis (veno-occlusive disease), resulting in erections that are quickly lost.
