What causes an erection to rise?

Just a small question, this one, I searched around but couldn’t discover the answer. Physiologically, what causes an erection to rise upwards? I ask this because my erections actually seem to pull inwards and reduce in length once they’ve reached a certain hardness and angle. I had wondered if losing this feature of my penis might help with gains at some point.

Can someone furnish me with an answer please? :)

Wikipedia entry for "Erection"

:cheerlead : Post 100

What do I get? :gift:

I think it is normal that when an erection rises above horizontal 90 degrees, the NBP measurement along the top looks shorter. Pushing an erection downward lengthens the nbp measurement in other words.

Didn’t really answer my question, unfortunately…

But for your 100th post, you get this. :danceblu:

:)

(edit: I see mravg posted. I also see what you’re saying, mravg. But mine actually seems to retract INWARDS when it gets to a certain stage! i.e. it’s longer when 80-90% erect than 100% erect.)

I have gotten into a bad habit of answering thread titles. :(

I think the angle is determined by individual ligament lengths.
Shorter on top side, causes upward rise.

Boobies!

Big tits with nice pencil erasers and a nice round, muscular booty.

I was hoping for an inch of length. :p

Okay, here’s what I think is happening to make an erection point upward…

Check out the bottom two cross-sections in these illustrations:
pcorbc.jpg

As you see, the suspensory ligament (that gray thing just to the left of the vas deferens) is shaped sort of like a wide triangle that’s relatively constant in size. It stretches a little when you force your erection downward, but not much. The penis, in contrast, has considerable capacity to change size, particularly when it fills with blood.

As a high-school-dropout/liberal arts major, I can’t precisely describe the process anatomically or physics-wise, but the attached picture conveys what I sense is happening. I took a one of those blow out noise makers and attached a piece of tape from the tube to about an inch up the paper part that unfurls when you blow through it. The tape was invisible when I took this picture with my camera phone, so I’ve put in a little triangle that’s intended to represent the suspensory ligament.

The actual shape of the ligament in the body is not so conveniently proprotioned — with 90 and 45 degree angles — as the triangle in my photo, but I suspect the angle of erection has a lot to do with the shape and alignment of suspensory ligament.

Penis angle seems to be a combination of ligament tightness and the manner in which the base is attached to the pelvic bones. The two erectile chambers, the corpora cavernosa (CC), are closely attached to each other for most of the length of the penis. However, deep inside they diverge and each side is adhered to the pelvic bone. When flaccid the CC hang down. As they fill with blood the natural upward angle is achieved because of the angle at which the two crura (“legs” or the internal part of each corpus cavernosum) are attached to the bone. When completely filled, the CC return to the same position each time because the attached base is always in the same position.

However, I think the suspensory ligaments also play a part and as we get older the ligs tend to be more relaxed and our penile angle decreases. So the upward angle is probably due to a combination of the base attachment angle and the tightness of the ligaments. Short of cutting the ligs there’s not much you could do to change this.

Why do you lose length? I believe the CC tend to shorten as they become fully filled. As their individual girth expands it tends to pull in on the free (distal or far) end. You can’t change that part either.

This thread has some diagrams that might be helpful.