Female reproductive cycle, it is a very complicated topic
because so many things are going on side by side so we will try to understand it in a very logical
way and I will try to make it very easy for you. Hello! I am Dr Aizaz from medicovisual.com welcome
to this visual [Music] Lecture. So, what is female reproductive cycle? Female reproductive cycle it
consists of series of monthly cyclical changes in the female body that makes the pregnancy Possible.
In female body, the major changes major monthly changes that occur they occur in ovary and uterus
but these changes are not occurring only into these organs but these rhythmical changes they
occur in almost whole body of the female even there are some behavioural changes that occur
even the basal body temperature slightly changes throughout the cycle.
Female menstrual cycle is another name for this cycle menstrual mean monthly some people simply
call it menstrual cycle. Right, but I think the complete name should be female monthly or female
menstrual reproductive cycle because it is concerned with reproductive ability of a female.
So, as I have told you previously, major changes occur in two organs what are those organs
uterus and changes that occur each month in the uterus of female it constitutes female
monthly or simply uterine cycle and changes that occur in the ovary of female these are,
This, it constitute ovarian cycle. This, these complete sum of all these changes
it constitutes the female monthly reproductive cycle. So, in this introductory lecture
we will discuss briefly these two Changes. Right, and then in the upcoming lecture we
will delve into details of these changes and the other changes that occur in this. Right,
So, as I, as we have previously discussed that Female, she start creating the primordial
Follicles, right, even before she is born and these primordial follicles these are,
these follicular cells, these primordial follicles contain this primary oocyte
and primary oocytes all these are arrested in prophase one of meiosis. Right,
each month about 15 to 20 of these primordial follicles start maturing
and out of these 15 to 20 primordial follicles single best follicle is chosen. single best
dominant follicle is chosen to be released into the Fallopian tube in the hopes that it will get
Fertilized, it will lead to pregnancy. Right, ultimate goal is to undergo Pregnancy. Right,
So, in first phase what happens that 15 to 20 follicles start growing, right,
because follicles are growing so this time period, this part of this reproductive cycle
is called follicular phase of ovarian cycle as far as ovarian cycle is concerned. The first phase is
follicular phase. Clear? I think females are quite optimistic creatures as far as their
bodily functions are concerned. why I am saying this? This is because when follicles start growing
even at this stage the female body is so sure that pregnancy will Occur, that even at this stage she
start creating the home for the baby. Right, home for the embryo and this is very special
home. Let's make it transparent and see what's inside this home. It is a multi-storey home with a
special tree inside it and there are some special windows in this room. Right, and what is that home
where does the baby go? When the embryo Come here into the this uterine cavity it then burrows
inside this uterine wall, in the innermost uterine wall. What is the name of innermost uterine wall?
Endometrium, endometrium, yes so embryo burrows inside this endometrium that is,
that is what we call implantation. Right, so, this endometrium is the home for the baby. So,
she starts creating this endometrium actually endometrium is already there but it is very thin
so she start proliferating the endometrium that endometrium will become thick enough
to support the baby. Right, so here is that home here is the proliferated
endometrium there is these trees. What I mean by trees is this blood vessels and these
special uterine glands that are shown in that diagram in that analogy as windows of that home.
Initially it is very thin, right, initially endometrium is very thin
but during this phase while the follicles were growing, follicles were growing in the ovary
meanwhile in the uterus endometrium Proliferated, home of the baby was Created. Right, so what is
this phase? This is proliferative phase of uterine cycle. So, the follicular phase of ovarian cycle
is the proliferative phase of uterine Cycle. Two things are going on side by side. Right, as the
follicles were growing in the ovary, Uterus, uterus, uterine wall was Proliferating. So,
proliferative phase here and what is this phase? Follicular phase. And then what happens that
this secondary oocyte it is released into fallopian tube here in into the fallopian
tube and here in the ampulla of fallopian tube sperm may come and fertilize it.
Right, as it is released into this Fallopian tube what happens that so here is that Secondary oocyte
as it is released into the fallopian tube what happens that the structure that remains behind
It, it accumulates lots of fat and because of that accumulation of fat it acquires yellow
colour so we call it yellow body Luteum, corpus luteum, corpus mean body, Luteum means yellow. So,
this yellow body is formed and this yellow body has a special function.
As soon as this yellow body or corpus luteum forms it starts secreting a special substance called
progesterone and this progesterone it goes to uterus and it acts as a message for uterus
that “yes! we have released this ovum which may get fertilized. So, you start preparing for
the food of baby.” Right, so baby has to come from, from this place all the way up to here.
It has to travel a long distance. So, it may be tired. So, it needs the food. So,
it starts preparing for the food and how come? So, what happens that these uterine glands or windows
they become deep and functional, they start pouring out special nutritious fluid.
Right, what is the significance of this nutritious fluid is that when baby will come here into this
uterine cavity it will be able to get nutrition from this nutritious fluid. Secondly, these cells,
they become laden with glycogen, these cells they become filled with Glycogen. So, when the embryo
will burrow inside this uterine wall embryo will be able to get nutrition and finally even baby
Will, it will be able to learn to fetch the food, fetch the nutrition directly from the blood
that is uteroplacental circulation will Start. We will discuss the detail later.
Then it can, it will be able to easily get that and that is why these vessels, they become large,
Tortuous, branchy and, and engorged. So, clear? So, coming to that house analogy that
the uterus she has set the table for the baby what is this table? These glycogen filled cell
and then it also start throwing fruits from these windows that is nutrition, nutritious fluids
start secreting from these glands. Right, and finally then there are these Fruitful, branchy,
tortuous large trees. Beautiful, fruity trees are there for the Baby. Clear? I am so amazed
that even at this stage the mother has arranged so much for the nutrition of the baby. Right,
and by the way what should be the name of this phase? This is of course post ovulatory
Time. Right, so as far as ovaries are concerned major change is that there is formation of corpus
luteum. So, it is the luteal phase of ovarian Cycle. This post ovulatory period it is luteal
phase of ovarian cycle and what happens in the, in the uterus? At this time is that these uterine
glands become functional and they start secreting this nutritious Fluid. So, it is secretory phase
of uterine cycle. So, secretory phase of uterine cycle is the same time when there is luteal phase
of ovarian cycle. Again two things going on side by side. So, two cycles running side by side
female body will keep on waiting for the embryo to come for about 14 days and if within 14 days the
embryo does not come her body will become very sad and she will destroy this home and what I mean by
destruction of this home is that this endometrium it is shed off. Right, and when endometrium is
shed off bleeding occurs, and that is what we call monthly bleeding or Menstruation. Right,
average duration of this cycle is equal to days or days in a lunar month. That is about 28 to 29
days. That is Average duration of this cycle but normal range is about 21 to 40 days. On about 14th
day, on about 14th day of this cycle ovulation occurs that is secondary oocyte is released into
fallopian tube that is called ovulation. We will discuss all these things in upcoming lectures.
The period before ovulation is obviously pre-ovulatory phase of the cycle and period
after ovulation is post ovulatory phase. Now, we are reviewing all those things.
Right, and the follicular phase this pre ovulatory phase is follicular phase of ovarian cycle because
follicles start Growing. Right, and it is in first four or five days menstruation occurs and then
little time is the proliferative phase of uterine cycle that when endometrium starts proliferating,
Right, and regarding post ovulatory phase what happens in the ovary that corpus luteum forms.
So, it is luteal phase of ovary. Right, and what happens in uterus that secretions start pouring
so it is secretory phase of uterine cycle. clear up till now? In next lecture we will talk about
what Happens, we will talk in a bit more details that what happens in this pre-ovulatory phase.
Right, and then in next lecture we will discuss what is process of ovulation and how it occurs and
in last lecture we will discuss what is post ovulatory phase? What happens in the
post ovulatory phase? Another important thing to discuss here is that what is oligo menorrhea?
If the cycle becomes longer we call it oligo menorrhea? Why we call it
oligo menorrhea? oligo means less and Menorrhea mean of course menstruation.
If the cycle becomes longer than normal that is more than 40 days, for example, let's say 45 days
then what will happen that female will experience less number of cycles or less number of times she
will experience the menstruation in her lifetime because cycle cycle is longer. Obviously,
and if cycle becomes shorter than 21 days, cycle becomes shorter female will experience more than
expected number of menstruation in her lifetime and that is called poly menorrhea. So, what is
poly menorrhea? It means shorter period, shorter menstrual cycle. And what is oligo menorrhea? It
means longer menstrual cycle. Clear? And here another important thing to discuss is that
this phase, the follicular phase or proliferative phase usually it is the culprit in shorter
or longer period this may be variable. Right, because follicles, they may take some time,
extra time to grow or follicle they may grow earlier which leads to variable period but usually
this period is about 14 days. It is almost always of 14 days. So, she keeps on waiting
for the embryo to come. For about 14 days and if within 14 days, She, the embryo does not come
she will shed the wall and start a new Cycle. Right? Thank you so much for watching this video.