Erection Facts
An erection is the result of a
combination of both physical and psychological stimulation.
They are started with nervous responses between the brain and
the muscles Various neurotransmitters in the brain (including
acetylcholine, epinephrine, and nitric oxide) create nerve
impulses that then trigger the muscles in the penis that
control blood flow into the corpous cavernosa. These muscles
relax, allowing large amounts of blood to flow into the penis.
The spaces in the corpous cavernosa then fill with blood..
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