- [Instructor] For this chapter on the
human reproductive system,
we're looking--
Starting off with the male reproductive system.
Now the testes will be the main organ
of the male reproductive system.
The testes, their main goal?
Producing sperm.
They're located outside the body though,
they're located in the scrotum,
which is a sac of skin.
This skin, by being outside the body,
allows for lower temperature.
Now this lower temperature is important
because lower temperature helps
to produce sperm more efficiently.
But the scrotum itself can be either elevated
or depressed depending on the temperature.
There are smooth muscles just below the skin
that can either help to bring the testes and scrotum
a little closer to the body
or help to move it away from the body.
So this means the scrotum and testes
have self-regulation of temperature.
Now inside the testes,
are tons and tons and tons of tiny little ducts
called seminiferous tubules.
These seminiferous tubules are where the sperm are produced.
As you go from the testes,
you leave out into the epididymis
and then through the ductus deferens.
Now the ductus deferens also known as the vas deferens,
is what carries the sperm from the testes
up into the male body.
The ductus deferens, as it transports around,
it eventually transports it down to the actual penis,
which is where the ejaculatory duct is.
So we start with production in the seminiferous tubules,
that's where sperm are produced.
They are then transported to the epididymis,
they're stored here and the epididymis
helps to get them ready and motile.
They go through the ductus deferens,
which could be also called the vas deferens,
this is the single tube on each side,
that carries the sperm from the epididmyis
up into the body and down towards the penis.
It then leaves through the ejaculatory duct into the penis.
There are also several other glands
that are accessory glands.
Now these accessory glands
will never actually contain sperm,
the sperm do not pass through them.
Their only job is to help make sure
the sperm stay alive and help them exit the body.
The first one up is the seminal vesicles.
Now these seminal vesicles are
where most of the seminal fluid is produced.
One of the major important parts is going to be fructose.
Fructose is a simple sugar.
It's a simple sugar that will provide energy to the sperm
as they travel.
The prostate gland.
Now the prostate gland can actually
have the sperm traveling through it in a duct,
but the majority of the gland
has nothing to do with the actual traveling of sperm.
Instead, what it helps to do,
is secrete this alkaline fluid.
Well this alkaline fluid is meant
to raise the pH in the vaginal canal.
It's helping to take that acidic nature
in the vaginal canal and raise it towards neutral.
Trying to protect and keep the sperm alive.
You have the bulbourethral gland.
The bulbourethral gland is secreting this
kind of thick mucus.
The mucus is going to be secreted
before the actual seminal fluid.
The purpose of this lubricating mucus
is to help clean out the urethra.
Because the urethra in males
is used for urine and for seminal fluid.
That means you have the waste product with the gametes.
So by using the bulbourethral gland,
it helps to clear out any of the remnants of the waste
that was part of urine.
So the sperm that's traveling through
are not coming into constant contact
with waste products that were in the urine.
So the bulbourethral gland,
clearing out and cleaning the urethra,
and also helping to provide some lubrication
for the gland's penis, or the head of the penis.
Here we have some diagrams
illustrating the male reproductive system.
The left-hand view, the one that's letter a there,
you can see is a lateral view,
you're looking from the side,
as if the body was cut in half.
On the right, letter b,
that's going to be a posterior view.
Looking from the backside or the posterior side,
toward the male reproductive.
So what you see already, just kind of orientate,
we have the urinary bladder and ureter,
parts of the urinary system.
We have the rectum and anus,
part of the digestive.
We have the vertebral column and pubic symphysis,
part of the skeletal system.
So all these things are around
and intertwined with the reproductive.
We'll start with the testes.
The testes is the sight of sperm production.
They're held outside the body.
The epididymis is where the sperm
can be stored for a period, held in place.
The epididymis is going to be kind of a cap,
or covering over part of the testes.
Now we've said the testes are external,
they're held in place by the scrotum.
We then can travel up into the body,
on the ductus deferens, or know as the vas deferens.
This is what will allow the sperm
to be transported into the body cavity.
It's then traveling around to the seminal vesicles.
The seminal vesicles will add fluid into the sperm.
Helping create that seminal fluid.
We can then travel down into the ejaculatory duct,
which leads through the prostate gland.
Part of the prostate gland also
helps to add secretions into seminal fluid.
We're then down into the bulbourethral gland.
Now the bulbourethral gland, if you remember,
was meant to secrete a mucus.
This mucus is meant to clean and clear out the urethra
before the sperm pass through.
You then enter the urethra.
The urethra goes all the way
to the external part of the penis.
So it's the last structure before it leaves the body.
The penis itself pretty much,
as you can see here,
is this bluish and purplish coloration.
It's not just external.
You can see on the lateral side,
which is the left-hand view here,
that it also goes into the body,
to kind of form an anchoring point.
All the blue itself is referred to as erectile tissue.
The way the erectile tissue works is
blood will actually flow into the erectile tissue
and fill up an open or a cavernous space,
where the blood will not be allowed to leave.
So the blood will keep pumping in without going anywhere
causing the erectile tissue to fill up.