Dear Dr. Myrtle,
Do women really get erections? How can they--they don’t have a penis!
Technically, it isn't a penis that becomes erect. The clitoral caverns inside of the penis are the structures that become engorged and erect. So when the clitoral caverns swell with blood flowing into the clitoris, it pushes on the penis, so that from the outside the penis appears wider and longer with sexual arousal.
Therefore, because all mammals have clitoral caverns, all mammale get erections regardless of their gender.
It just isn't as obvious.
When the clitoral caverns swell from engorgement, the clitoral structure swells and stretches the outer shell called the tunica. Because the shaft of the cis-female clitoris is bent back towards the body (at the suspensory ligament that attaches the clitoris to the pubic bone(s), engorgement will straighten this bend.
For many cis-women, as the clitoris straightens, the clitoral glans/tip becomes harder to see because it is obscured from view by the clitoral hood.
What’s in a name?
A penis is analogous to the vulva, since both of these structures are collections of genital parts. Both a penis and a vulva contain a clitoris among other structures.
Erectile function is specifically related the corpus cavernosa inside of a male penis, which fills with blood for purposes of either oxygenation or erection. Erectile function in women happens in exactly the same structure--16th century European anatomists simply named the structures differently: male = corpus cavernosa vs. female = clitoris.
There are slight structural differences between a male corpus cavernosa/clitoris and a female clitoris:
- The male clitoris has a thicker outer shell (tunica albuginea).
The female clitoris has a thinner outer tunica.
The male clitoris has a thicker shell (tunic albuginea (al-bue-GIN-e-a)) which more effectively holds blood inside the caverns. This means that the male clitoris, once engorged (filled with blood) holds the erection longer. This hard shell presses against the outflow spigot/veins and traps the blood inside more easily. Because of the thinner shell, blood can flow out more easily from the female clitoris. Functionally, more consistent direct stimulation is necessary to maintain female erections.
- The female clitoris is approximately 4 inches long when measured from the base of the clitoral legs (near the vaginal opening) to the clitoral tip.
- The male clitoris is approximately 5 inches long when measured from the base of the clitoral legs to the clitoral tip.
- The male clitoris is situated further away from the pelvic bones than the female clitoris.
- The female clitoris has more nerve endings at the very tip (head) because the female clitoris doesn’t expand as it does in the male, so the nerve endings don’t spread out as they do in the male.
- One can directly touch a female clitoris when the clitoral hood is held back.
- One CANNOT directly touch a male clitoris because it is completely surrounded by the penis.
So, pretty far from Mars and Venus, it appears that men and women were both born on Earth.