The Penis contains two chambers, made of spongy tissue, which run the length of the penis. This tissue contsists of smooth muscles, fibrous tissue, spaces, Veins and arteries. These chambers (called corpora cavernosa) are surrounded by a membrane. The Urethra, which is a common passage for urine and Semen, runs along the underside of this chamber. comprar viagra
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When stimuli from the brain and other local nerves causes the smooth muscles of the chambers to relax blood flows in to flood the open spaces and gets trapped, creating a pressure in the chambers hardening the penis.When these muscles contract, blood trapped is allowed to low out, relaxing the penis. kaufen viagra