An erection causes the male penis to become larger in length and girth. It can occur spontaneously, and is a result of signals sent to the penis through the nervous system.
The male reproductive system is made up of several parts that all work together to stimulate sexual activity and influence the pro-creation process. The male penis is, perhaps, the central part of the sex organs, as it contains many of the tubular structures that help make and carry semen and release it from the body. Before this can happen, however, an erection must take place.
In males, an erection can be achieved by two mechanisms that occur together. They are: the increased inflow of blood into the vessels of erectal tissue, and decreased outflow. Here, the vessel system is known as the corpora cavernosa and the corpus spongiosum.
Muscles in the region of the penis relax, which allows blood to enter these sponge-like tissues. At the same time, the contraction of other muscles reduces the blood outflow from the penis, and the enlarged penis then exerts pressures on the exit veins, thereby, causing a further reduction of outflow.
As the blood flows in, the penis stiffens and increases in both length and girth. It then rises to an angle that can vary among individuals to anywhere from below horizontal to almost vertical.
In some cases, erectal disfunction may occur, causing a reduced ability for a male to have a penile erection. When this happens, it is impossible for him to achieve normal sexual intercourse.
In recent years, several drugs have been developed to help relieve this problem and stimulate a normal erection. These drugs are prescribed during a visit to the doctor, who will then evaluate the situation and decide if they are necessary.
An erection occurs when signals from the nervous system are sent to the penis. Stress can decrease a man’s ability to become erect. Ejaculations are also caused by signals sent to the penis from the nervous system, which can explain why a male often loses the erection just after he ejaculates.
An erection can last for a varying amount of time. Some happen but then quickly dissipate, while others are more lengthy. There are even times when a male is unable to get an erection, but this is usually no cause for alarm, as certain conditions and environments may have an influence.