It's time
to talk more about erections,
because let's face it,
they're pretty important
for multiple reasons,
especially from the standpoint
of reproduction.
Now, much of the discussion
about erections will often focus
on the male erection,
and that may be
because the
male erection is a little bit
more noticeable
than, say, like the female erection.
But make no mistake,
females very much come equipped
with functional erectile tissue.
But how important is the female erection
from the standpoint of reproduction?
Because as we've already alluded
to, a male erection
and the release of sperm cells
is pretty important
when it comes to successfully completing
reproductive intercourse.
So does that female erection and climax
also play a key role in successful
reproductive intercourse,
or is it more of an added
bonus to the female for other reasons?
Well,
we're about to find out,
as well as just talk about how it works.
So let's jump right into this
reproductive anatomical awesomeness.
Now, one thing I want to start
with, it's very interesting
is that male and female
erectile tissue structures
are surprisingly very similar.
So throughout this video,
we're going to reference
these things called
homologous structures.
And for our discussion,
these would be things that develop
from the same embryonic tissue.
So, for example,
the testes
in the ovaries
develop from the same embryonic tissue
and are therefore homologous structures.
And more importantly,
for this erection discussion,
the penis
and the clitoris
are homologous structures
and have the same erectile tissue.
So let's start
by taking a look at the clitoris
and therefore the erectile tissue
so that we can figure out everything
that's going on here.
So the clitoris is essentially
the cylindrical mass of erectile tissue.
And as you can see,
it's made up of various parts.
It arises from
two leg like extensions
in the word for leg in anatomy is cross
or the plural version is cross.
So these are called
the crown of the clitoris
and the Clara are located on
the actual is steel
and pubic bones on both sides.
And as we take a look at this
on the cadaver dissection,
let me first orient you.
This is an inferior view
or looking from the underside.
And keep in mind, to get to this view,
we also had to remove
the external genital structures.
So we had to remove things
like the labia, majora, labia, menorah.
And you can also see
some pretty large muscles here.
These are often referred to as the groin
or the adductor muscles.
Just again,
for another frame of reference.
But finally,
we can take a look at the right
cross of the clitoris
right underneath my probe here.
The left cross,
we can't see
because it's covered up
by some of these tiny
and even amazing skeletal muscles
that we removed on the other side.
But these skeletal muscles
we'll talk about in
just a little while,
because they get involved
in helping to maintain the erection.
Now, the crust
or the core of the clitoris
will actually bend off of the pubic bone
and come together
and unite
to form the body of the clitoris.
Now the body of the clitoris
is homologous with the body
or the shaft of the penis.
And you probably already
guessed that
the crust of the clitoris
would be homologous
with the crust of the penis.
But when we take a look at it
on the cadaver dissection, you can again
see here would be the body
of the clitoris.
And again,
this would also be covered up
by external genital structures.
The only visible portion of the clitoris
is the very end or tip of it,
which is called the glans clitoris.
Shocker.
Homologous with the glans penis.
But the glans
clitoris is located
at the anterior junction
or where
the front of the two
labia minora
kind of unite or come together.
And the labia menorah
are these bilateral folds of skin,
the inner bilateral folds of skin
that pretty much surround
the entrance into the vaginal canal.
And if we go back to the cadaver
dissection here again, there's the body.
And then going down
to the end of the tip,
this would be the glans clitoris here.
Now the glans is packed
with sensory nerve endings.
So very important for sensation
as well as initiating
and maintaining the erection.
So how does the initiation
and the maintenance of the erection
actually work?
Well, we're going to approach this
from two different scenarios.
Now, these scenarios can happen
independent of each other,
but they can also happen in conjunction
or at the same time.
So the first scenario will mentioned
is simply just tactile stimulation
or touch of the glans
and other surrounding genital structures
that'll send a sensation
or a signal
into the spinal cord
through a nerve called the dental nerve.
Now, if you've watched our previous
erection video,
you know that
few dental translates to that
which you should be ashamed of
because apparently
the anatomists hundreds of years ago
were ashamed of their genitals
for some reason.
But once that signal gets relayed
into the sacral portion
of the spinal cord,
it will specifically go
into the sacral levels S2 three and four.
And when I was teaching this in college,
we had a saying as two, three and four
keeps the penis off the floor.
But it also certainly works
as this as two, three and four
also keeps the clitoris off the floor.
So it works for both.
But part of that signal,
yes, will go up
the spinal cord to the brain
so that you are aware of such
tactile stimulation
or what's going on down below.
But it doesn't technically have to
this scenario
that we're talking about
with tactile stimulation
actually works
primarily reflexively,
meaning that
the signal will go on to the spinal cord,
but most of that
signal will just get kicked right back
out of the spinal cord
and go directly
to the internal erectile
tissue of the clitoris.
I kind of think of it this way.
It's like
we're going to give the brain
a common courtesy of being like,
Hey there is a signal coming
in, we're going to let you know
something's going on in here,
but we don't really need your permission
to do this.
We're going to just send that signal
right back out to the clearest
and initiate the erection.
So somebody with a spinal cord injury
could technically
still get
an erection initiated
from this tactile stimulation.
But that doesn't mean
the brain doesn't get involved
in initiating and maintaining
the erection.
It's just with that particular scenario,
it doesn't technically need it.
Now we know that the best erections tend
to happen with the brain
and tactile stimulation
working together in conjunction,
meaning that the brain starts
to send signals down from
say like you see someone
that looks very nice to you,
you have certain thoughts
and imaginations.
Even certain smells can be arousing.
Maybe somebody whispers
something in your ear that excites
you in a very specific way,
and that signal can come down
and it can initiate an erection.
If somebody wasn't being tactile,
stimulated,
or if it's occurring at the same time,
these signals will converge in that
SW two,
three and four region of the spinal cord
and send these signals out
through certain
nerve fibers
to go to the internal structures
of the clitoris
and these nerve fibers
will release their neurotransmitters,
which will then cause nitric oxide
to be released
within the erectile tissue.
And this is where the magical opens.
So if we were to take a cross section
or cut
right through the body of the clitoris,
we would see that
there's these two distinct masses
of erectile tissue
or erectile tissue
bodies called the corpora,
cavernous rossa.
Now remember,
the crack came off the pubic bone
and came together
to form the body of the clitoris.
And that's what these things
arose from those.
And now we have the corpora cavernosum
and this is a vascular cavernous
erectile tissue vascular
because there's lots of blood
that can go in there and cavernous
because there's these hollow spaces
or sinuses
that are going to fill with blood.
So nitric oxide
has this powerful effect
as being a powerful vasodilator,
so meaning the blood vessels
within will open up
and allow
for more blood
to come into this erectile tissue
and also affects this cavernous
erectile tissue
by relaxing the smooth muscle within.
So those spaces will enlarge
to allow for even more blood to fill.
Now this will enlarge the clitoris,
obviously not to the same degree
to say like an erection with the penis,
but the clitoris will enlarge compared
to its not erect state nonetheless.
So back to the question
we had at the beginning of how important
is a female erection
and climax to the successful completion
of reproductive intercourse
or just even reproduction in general
because there are artificial means
to also do this?
Now granted,
the majority
of these episodes of consensual coitus
or intercourse
are not just about creating a baby
or reproduction.
There are various reasons
why people participate in intercourse.
It feels good stress, reliever
bonding and connections
formed between people.
Various other reasons
that we could come up with.
But from the standpoint of purely
getting sperm
cells from the male reproductive tract
and into the female reproductive
tract to fertilize an egg,
how important is that
female erection in climax?
Well,
you probably could have answered
at the beginning of the video
that it's technically not necessary.
As long as the sperm cells
get into the female reproductive tract,
it could technically
still fertilized egg.
Now, beyond that
being just bad business practices
to not have
the erectile
tissue fully
engaged with all parties involved,
that doesn't mean
that the female erection in climax
can't help
with this process of fertilization.
And one of structure
that we haven't mentioned yet
is another erectile tissue mass
that's found on both sides
of the vaginal canal,
called the bulb of the vestibule.
Now, if we take a look
at that on the cadaver
dissection, again,
we can just reference
that crest of the clitoris
that we saw earlier.
But right underneath my probe here
is the bulb of the vestibule.
Now, we can't see it as well
on the left side
because it's covered up with a muscle
called the Bobo Spongiosis.
muscle,
which is a pretty good name for a muscle
that's covering
the bulb of the vestibule,
but that muscle,
when it contracts,
will just help facilitate
the function
of this bulb of the vestibule,
which is when it engourges
with blood or becomes erect.
It will narrow the vaginal canal
around the penis
and thereby increasing the stimulus
and facilitate
the climax
and the release of the sperm cells.
Now, you could make the argument
that's just helping
the male reproductive tract,
but if we keep digging
a little bit deeper,
we're going to see some really cool
things that happen
with the female reproductive tract.
Now, one of the
things that I need to mention is that it
is known
that a female inseminated
naturally through intercourse, tends
to be more fertile
or have an increased odds
of getting pregnant
as compared to
if the same female
were inseminated artificially.
Granted, artificial insemination works.
It's just all things being equal,
the natural intercourse
tends to increase the odds.
So there's the question of, well,
why is that?
And it's thought to center around
female climax.
Or in other words,
what happens during female orgasm,
during female climax,
some awesome things will occur.
One of those
is that the pelvic floor
muscles will start
to rhythmically contract
and this will help propel
the sperm cells further
upstream towards the uterus.
The uterine canal will also dilate
or open up,
which will help facilitate the flow
of the sperm cells.
Oxytocin is also released
from the pituitary gland.
Oxytocin is a hormone
with various functions,
one of which is to cause
the uterus to contract.
And if there are any sperm
cells in the uterus,
that contraction will help propel
the sperm cells even further,
getting closer to fertilizing that egg.
So you can see just
from a reproductive standpoint,
that the climax within the female
can help increase the odds of that.
Now, we could talk about the odds
of successful fertilization
from a different perspective
or a different numbers game, if you will.
Let's say
a female had multiple previous encounters
of enjoyable intercourse
that included Climax,
said female
would probably be more likely
to continually engage
or more frequently engage in intercourse.
And we can make the argument
that this would also increase
the odds of successful
reproductive intercourse.
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