There is variety
of abnormalities that may occur in the development
of the vagina and uterus. Imagine again the
coming together of the paramesonephric ducts.
This will normally meet in the midline, and
then fuse to give the uterus, vagina, and
the uterus in the upper part of the vagina.
So anything which interrupts this coming together
in fusing is going to give rise to a variety
of different morphologies. One may have, for
instance, two completely separate uteruses.
In this condition, there will be a significant
impact on the likelihood of becoming pregnant.
All the conditions may be similar but not
quite so marked and this can range all the
way from a [inaudible 00:13:56]uterus at the upper part
to a septum in the center of the uterus.
But these are all variations on the same general
idea. In some cases, one paramesonephric duct
may not form properly, and therefore, only
one horn of the uterus will develop normally.
This can have a significant impact on the
likelihood of conception when the mother is
trying for a child. We looked at the complex
process of the descent of the testicles.
In fact, what we can see is that this is something
which is quite likely to go wrong.
Indeed, 3 percent of male babies may have an undescended
testis at birth. And because this process
happens relatively late in development, premature
babies are even more likely to have an undescended
testes or testis. If this happens, then either
it can be adjusted surgically or various chemical
compounds can be given to try and accelerate
the process of descent of the testis.
If a testis remains inside the body cavity, the
raised temperature that it?s exposed to
compared to this normal temperature in the
testis sac means that it may not produce
viable sperm. In a small number of cases,
there?s a possibility that because it?s
in the wrong site, its development may become
very abnormal, indeed, even cancerous.
And this is something we?d have to be looked
for if a testis had failed to descend when
we need to consider whether or not we had
to identify where the testis was and consider
removing it. There are other abnormalities
that can take place as a result of the process
of descent of the testis. Essentially, these
will rely on in continuing of the opening
of the vaginal process. This may incorporate
a loop of the gut, and the gut may then be
cut off from its normal blood supply and become
necrotic. Alternatively, the processus vaginalis,
the vaginal process, may begin to build up
fluid and create a large hydrocele, and this
can grow to very considerable size, indeed.
These possibilities may also occur in females,
even though of course they have ovaries rather
than testis because the vaginal process is
present in both sexes. A relatively common
malformation of the penis is failure of the
zipping up of the folds of the urogenital
sinus to take place properly and if this was
to occur, there would be a gap or opening
on the underside of the penis, a condition
known as hypospadias. The penis, in this condition,
males will be curved downwards and be smaller
than in normal size. So then, we have looked
at the development of the genital system,
starting with the primordial germ cells, looking
at the development and migration of both ovaries
and testis, and looking at the development
of the external genitalia in addition.
We?ve also touched on some of the most significant
developmental abnormalities present in
this genital apparatus. Thank you very much.