Hi. Sorry, it's been... it's been fucking ages since I've uploaded anything, but uni's been kicking my ass.
And, yeah. Well, I thought that maybe you would be interested in helping me study, and I'm dead serious, I'm going to be going over all of my notes from last week's classes.
And I just feel not as weird, like, practicing out loud, like speaking out loud to essentially you guys than I do just talking to myself in my flat.
So that's what I'm gonna do. And I thought this would be a perfect thing to record, because this topic is the male reproductive system.
So if you would do me the favour of following along, I'm gonna do like a quick anatomy thing, and then just go into the physiology of erection and ejaculation.
And hopefully, because I don't have a penis myself, I don't know if all of this... because all of this is just a book, you know, it's just text, it's just theory.
And I can't feel for myself how erection feels or how ejaculation feels. It would be, you know, interesting to hear from you, from those of you who have penises.
If the theoretical teaching matches the practical reality.
Okay, so a quick anatomy lesson. I... ideally, if I had a male study partner or a male subject, I would have him undress, at least from the waist down.
And, you know, expose the area. And I really, I would like for you to do that.
So just remove any obstructing clothing or duvet covers or anything like that. And, you know, now that I can't do it, you can do it.
Give yourself a quick check over. So, you should find, at the very top, a patch of hair, unless you've done something to actively remove it.
And then going down from there, you should find the actual shaft of your penis.
And at the end of the shaft, you find either the prepuce, the foreskin, or if you are circumcised, you'll find the glands of the penis.
And the glands of the penis is the most sensitive area of the penis, and it is like the clitoris of the female.
Unless the penis is already engorged, it should feel soft, and it should be moveable. There should be no pain.
If you lift the penis so that the glands, the head of the penis, is now pointing up towards yourself, you will find the scrotum just behind the penis.
The scrotum is where the testis, the testicles, are stored, and it's very important that you frequently give them a little check-up.
And I think now would be as good a time as ever to run your hand down to your testicles and squeeze them gently between your thumb, your pointer finger, and your middle finger.
Just feel around. They should feel sort of like a hard-boiled egg, have a little bit of give, and the testis should be able to move around within the scrotal sac.
Most people have two testicles, but for whatever medical reasons, some have only one, some have none.
If you have a testicle behind, sort of if you move your forefingers in sort of a scooping motion behind the testicles and hold them fixated,
you will, on sort of the back and top pole of the testicle, feel sort of like a little growth there, and that is perfectly normal, and it's supposed to be there.
It's called the epididymis, and it's where all your sperm cells are stored. So, in the testicles and testis is where the sperm is produced, and then it's stored in the epididymis.
So, I think that's probably it for the anatomy part of this. Now, for the sort of physiology behind getting an erection, an erection occurs because of some sort of stimuli,
erotic stimuli, and it's very individual. What sort of stimuli helps or works? For some people, it can be the imagination of something that they would find erotic.
For others, it might be sight, if you see something erotic. For you, it might be sound. Some find smells to be erotic.
And for others, which might be you as well, after a little anatomy lesson, it might be something called tactile touch, which basically just means physical stimulation, touching your penis and your testicles.
What this sort of erotic stimuli, what I now imagine for you could be the stimulation of sound and touch, you have something called parasympathetic nerves in the S2 to S4 region in your spine.
And what this nerve does is it innervates an area inside the shaft of the penis called the corpora covenosa.
And this corpora covenosa is basically what you can feel if you take the shaft of your penis in your hand and you give it a little squeeze. It's what the bulk of the shaft is made up of.
And this tissue is erectile tissue, which means that it can expand. This parasympathetic nerve, which is stimulated, releases something called acetylcholine.
Yes, acetylcholine. Sorry, you really are just studying with me. And what acetylcholine does is it acts on the endothelial cells within the arteries in the corpora covenosa.
And the acetylcholine cleaves an amino acid called arginine to nitric acid and another amino acid, which isn't so important.
The important one here is nitric acid. Nitric oxide. Sorry.
What this does is it goes into the cells, the smooth muscle cell in the corpora covenosa, and it stimulates a small enzyme called guanil cyclase,
which turns something called GTP to cyclic GMP. And that cyclic GMP makes it so that the smooth muscle cell excretes potassium.
And when the smooth muscle cell excretes potassium, it causes something called vasodilation.
And that means that the artery, if you remember, that acetylcholine had an effect on, it expands. And when the artery expands, more blood flows to the tissue.
And this tissue, the corpora covenosa, was sort of a spunkiest tissue, and it fills up with blood.
And when this fills up with blood, it sort of, it pinches all the veins that are there to help with draining the penis from blood.
Because obviously if we didn't have these veins, we'd walk around with a hard on all the time, which isn't ideal.
But when this vasodilation happens, the corpora covenosa pinches off these veins.
And when that happens, we have sort of an influx of blood that fills up the penis and nowhere for the blood to go.
And this is how the penis becomes hard. Now, often, with a hard penis, something like physical stimulation would happen.
For people who are not circumcised, the foreskin plays a big role when it comes to masturbation.
In terms of sliding over the clans of the penis and sort of sheathing it, for people who are circumcised, some sort of lubricant is often very necessary.
Whether that be spit, or an actual lube, or some sort of body-safe oil.
And at some point during this physical stimulation, you will reach a threshold. What happens is you reach your threshold
and sympathetic nerves found from the T12 to L2 segments in your spine will stimulate the cerebral cortex.
And when the cerebral cortex is stimulated, it will stop the parasympathetic stimulation in the corpora covenosum.
And it will activate sympathetic stimulation throughout the reproductive organ.
So, what will happen is, the sympathetic nerve endings will synapse, and the first place we will find some sort of effect from this
is in the epididymis, so the sort of top and back of your testicles will contract.
Because as we remember from the anatomy part of this, this is where all of the sperm cells are stored.
So, as I can imagine, the balls will feel like they tend up, because they actually do, and the sperm is sort of moved forward
almost from peristaltic, like rhythmic contractions around the testes.
They will be shut into something called the vas deferens, which is a tube, sort of a tiny little tube surrounded by muscle,
which is also sympathetically innervated, which will then also contract and keep shooting these sperm cells forward.
And all of this sort of happens in the scrotum, and you will feel that as sort of a whole, as a complete contraction of the testicles.
So this will happen right behind your bladder.
The vas deferens will meet a vesicle called the seminal vesicle, and it is in this vesicle that seminal fluid is created and is stored.
And when the semen, or when the sperm meets with this seminal vesicle, which is also sympathetically innervated, and which then also contracts,
we will have semen. So the mixing of sperm and seminal fluid is what semen is made up of.
So now we have semen, and the semen will be sort of moved forward into what is now called the common ejaculatory duct.
And something really exciting happens with the semen here, because this duct travels into the prostate, and the prostate, if you're not aware, is located behind the penis,
in connection with your bladder, and you can access the prostate, or you can feel it, by going into your rectum.
And then on the side towards your penis, you can feel a sort of round, soft but firm structure, about a good knuckle deep in, and that's the prostate.
And it is through the prostate that the semen enters the prosthetic urethra, and this part of urethra sort of sits at like an ankle,
so we need something to help prevent the semen from moving up into the bladder, and we need something to help the semen sort of move past this bent,
and move out through the rest of the urethra and out. So the bladder is coated by a muscle, and it's a prosthetic innovation.
It also stimulates this muscle around the bladder, so the bladder contracts and helps prevent the semen from flowing up into the bladder.
And if you can imagine, the part of your penis that's inside of your body, just on the backside of that, just behind it, you have a big muscle called the bulbospongiosum.
Now, this muscle is so important. It is also innovated by the S2 to S4 segment of your spine, like the parasympathetic nerves,
but this nerve is called the pedendal nerve, and this nerve, when it interacts with the bulbospongiosum muscle, it releases acetylcholine,
which makes this muscle contract, and when the bulbospongiosum contracts, it shoots out the sperm, and it shoots out the semen.
So what's so interesting about this nerve in particular is that it's a somatic nerve, which means that it is under your control.
So what happens when you edge, for example, what you're doing is you are sort of with your will controlling this muscle to not contract,
and therefore, you get a buildup of semen in this area, just below your bladder, which also will create a pressure around your prostate.
Now, the last little bit of ejaculation will be this contraction of the bulbospongiosum, and it will shoot out the semen at about 11 miles an hour.
And once this has happened, as I told you, the sympathetic nerve will have turned off the parasympathetic nerve, and when the parasympathetic nerve is turned off,
it no longer innervates the endothelial cells in the arteries in the coposum cavernosa, which means that they can now sort of relax back into their normal size,
they're no longer dilated, and this will release the pressure from the draining veins, so the blood can flow away from the penis, and it will become flaccid.
I don't know if this was all over the place, or if it was kind of interesting hearing about the mechanics of getting an erection and ejaculating.
I would love to know if you have some sort of feeling, I would love to know if you can feel the way that your penis fills up with blood,
if you can feel the semen moving from the epididymis all the way down to just below your bladder, and if you can actually feel yourself controlling
this sort of last, last bit of muscle contraction before we have the final ejaculation.
Anyways, I hope, if not erotic, I hope that this was somewhat interesting, and thank you so much for just helping me study tonight.
Yeah, thank you.