When you get aroused, your brain releases a hormone and tells your body to send blood to your penis, which engorges the spongiosum and cavernosa and stimulates pleasure receptors. This is called an erection. Your penis is full of a spongy tissue which absorbs the increased amounts of blood and expands, causing an erection. Our exercises stimulate these cells in a manner akin to body building, and build new layers of cells onto the old ones. While you sleep your penis' stressed cells repair, strengthen, and grow back larger and stronger.
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