• hard at will and as soon as erect live erect. More blood to the penis also will increase penis size to its largest capability. What reasons a person's penis to get tough? There are unique chambers within the penis referred to as Corpora Cavernosa. When bl   RisaGen  ood flows into the Corpora Cavernosa at some point of arousal it is held there and your penis will become erect and tough. When you become older the blood waft might also lower or the muscular tissues and valve which maintain the blood in the penis becomes.