The internal mini-shaft on the bottom side of the penis

I’m not exactly sure what this is, whether it’s a blood vessel or the urethra itself, but it juts out from the bottom of the penis. Solonjk I know you know anatomy so maybe you can help out in knowing what this is exactly called.

One thing I know about this is that my libido is directly related to how hard this little section gets. When I took aspire 36 and got a really hard erection, this section still stayed soft, and my libido was still not good. After a while of using dermacrine sustain and regaining some libido, I noticed that it slowly began to get harder along with the rest of my erection. The harder this gets, the more pleasure I’m capable of feeling.

Has anyone else noticed this?