Erectile tissue in the clitoris and penis
Cross section showing the two corpora cavernosa near the top surface of the penis, and the corpus spongiosum surrounding the urethra near the bottom surface.
Erectile tissue exists in places such as the corpora cavernosa of the penis, and in the clitoris or in the bulbs of vestibule. During erection, the corpora cavernosa will become engorged with arterial blood, a process called tumescence. This may result from any of various physiological stimuli, also known as sexual arousal. The corpus spongiosum is a single tubular structure located just below the corpora cavernosa. This may also become slightly engorged with blood, but less so than the corpora cavernosa.