If you have a bent penis with or without erectile dysfunction, and want to understand why they penis becomes curved with Peyronie’s Disease, it is helpful to first understand the normal anatomy and function of the penis.
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Anatomy of the Penis, Cross-Section
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The main structures in the penis that contribute to erections are the paired corpora cavernosa. These structures that course along the penis deep to the skin are composed of a casing or covering called the tunica albuginea, and contain spongy vascular tissue. Important arteries and nerves that provide blood supply and sensation to the head of the penis travel along the top of the penis between the tunica albuginea and the skin.

Normal tunica albuginea is elastic and can stretch. During erection, blood fills the corpora cavernosa, and these structures enlarge and become rigid. In some ways, the penis is similar to a water balloon. Imagine a balloon that is almost empty. The balloon will be very flexible. If the balloon were to be filled with water, as the rubber expands, the elastic balloon will become longer, wider, and more rigid. In the penis, there is elastic tunica albuginea instead of rubber and the penis fills with blood instead of water. There are also many tiny veins within the penis that occlude, or pinch off during an erection, allowing the blood to stay within the penis.