How does an erection happen? Activeda Guide
An erection occurs when the penis becomes hard and enlarged due to an increase in blood flow. This process starts with sensory and mental stimulation in the brain, which sends messages to the penis via nerves. These messages cause the muscles of the corpora cavernosa to relax, allowing blood to flow in and fill the open spaces. As the blood vessels in the corpora cavernosa relax and open up, blood rushes in, gets trapped under high pressure by valves, and creates an erection.
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