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The Mechanism of Combination Birth Control

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⚡ Welcome to Catalyst University! I am Kevin Tokoph, PT, DPT.

Welcome back to catalyst university my name is kevin toke off please make sure to like this video and subscribe to the channel for future videos and notifications in this video we’re gonna discuss the mechanism of birth control and we’re gonna specifically look at birth control types that contain a mixture of progestins and estrogens so for example one of the

Common types of birth control the combination birth control is going to contain a progesterone analogue such as norge estimate shown over here on the left and it’ll also contain an estrogen analogue such as this one over here on the right ethanol estradiol but before we get into how these drugs actually work we need to understand a little bit about the menstrual

Cycle that occurs in females so here’s the menstrual cycle over here on the bottom left the menstrual cycle on average is going to be about 28 days now again there are variations in that that are just due to individual differences so we have day one right here it goes around you’ll notice it looks like it only goes to day 26 but again this means 26 to 32 because

There are individual differences okay not everybody’s biological clock is exactly the same now whenever you begin the menstrual cycle the menstrual cycle day one is the onset of menstruation the onset of bleeding okay we’ll talk more about that later on now from days 1 to 7 generally speaking and again there can be individual differences but this time in the

Cycle is considered to be for the most part infertile there’s no way generally that the woman is gonna get pregnant in this phase of the cycle now as you go from day 8 to day 19 of the menstrual cycle this is the phase of the cycle in which the woman is most likely to get pregnant because they’re the most fertile now again you’re gonna start with being relatively

Speaking the least fertile here at day 8 and it’s gonna peak around day 13 to 14 the midpoint of the menstrual cycle and again you can see it’s going to wane a little bit to a day a little bit less fertile there okay but the point is around day 13 or 14 which is about where the midpoint of the menstrual cycle is this is where you’re going to be the most fertile

Because this is about where ovulation occurs okay so ovulation is the process by which the egg having already matured is released from the ovary and once it’s released from the ovary then it has the potential to interact with sperm and become fertilized okay and again here you got start at day 20 going to basically the end of the menstrual cycle this is considered

Infertile time as well all right so in the menstrual cycle the egg is gonna have to mature inside the ovary as we mentioned okay you can see the egg it’s going to be maturing inside this follicle structure okay inside the ovarian wall okay and that follicle is going to get bigger and bigger and bigger and eventually when the egg is mature it’s gonna rupture out

Here and you see this a great they’re very small but at the tip of my mouse right there the egg has been released from the ovary that process as i mentioned is called ovulation okay and now that the egg is outside it has the potential to be to come in contact with the sperm cell and if the sperm cell penetrates the egg that’s the process of fertilization and

That’s what allows pregnancy okay and so that only can occur once you have ovulation which is going to occur again around day 13 or 14 of the cycle there’s a hormone that’s normally at play here and you see around the time of ovulation right here at the midpoint of the cycle in purple this line represents progesterone and we see here that progesterone levels

Start to increase pretty much at the onset of ovulation okay now what progesterone is going to do it’s going to do two major things here progesterone first of all is going to prevent the release of further eggs from the ovary okay so it’s gonna prevent further ovulation that’s important because the way the body works is generally it wants to focus on the one

Egg and it doesn’t want any more eggs following it okay so it just wants to focus all its energy on that one egg that has just been ovulated okay and the other thing that break the purge is stern will do is it’s going to prepare the uterine wall the womb wall for the possible pregnancy because eventually what the egg can do is it can implant in the uterine wall

And that’s actually where initially you have the process of development is in the uterine wall so you have to prepare that uterine wall and that’s what progesterone is going to do so to put it as simply as possible here you have one of two possibilities you either have pregnancy or no pregnancy in the case of pregnancy so fertilization occurs the progesterone

Levels remain elevated if you think about it that makes sense progesterone levels become elevated because you really need to make sure that that uterine wall the lining of the womb is in a perfect condition so that the egg can implant and you can have the pregnancy be successful okay so the progesterone has to remain elevated and you also don’t need the release

Of further eggs if you have no pregnancy so fertilization does not occur that at some point as you can see right here in my mouse is the progesterone levels start to fall okay so in no pregnancy the progesterone levels fall and that drop in progesterone levels induces what’s called menstruation okay okay so the lining of the uterine wall basically gets washed

Away so there’s no possibility that that egg can stick in the uterine wall because it’s basically getting washed away okay that’s the basic way to think about it and so it’s important to remember that this process of the increase in progesterone is occurring about halfway through the cycle okay over here in the first let’s say 14 days notice the progesterone is

Pretty much a flatline there’s no really no progesterone release there it only occurs at about halfway through the cycle and then at the very end it’s gonna drop in the case of no pregnancy so let’s remember that now getting back to these two drugs here let’s first talk about norge estimate which is actually the synthetic progesterone analog now the question of the

Day is if progesterone seems to be responsible for maintaining pregnancy why would you take a progesterone analogue something that mimics progesterone okay and the answer lies in the tie that you actually start taking the norge estimate okay so remember that the ovulation is occurring around day 13 or 14 halfway through the cycle that’s when progesterone levels

Start to increase you’re gonna start taking the norge estimate long before that in the menstrual cycle okay so you see over here in this figure that the progesterone levels are flatlined there’s no progesterone release if you take the norge estimate which is going to behave as progesterone you can imagine that this purple line is actually going to be elevated

Over here on the left side okay what that does is it tricks the body into thinking that ovulation has already occurred because remember under normal physiological conditions without a drug progesterone levels only become elevated halfway through the cycle and that’s the signal that ovulation has occurred if the progesterone levels or it’s analog nord estimate

Is elevated over here well before ovulation then the body thinks ovulations already occurred and it will not ovulate so this process of the egg getting released from the follicle never occurs so there’s never any egg there to get fertilized and that’s how noor justin mate works okay if you take norge estimate early in the cycle which again is going to be day one

At least of the birth control cycle okay then you’re taking that noor just to mate long before ovulation and so the body thinks it’s already ovulated so there’s no egg release therefore most likely pregnancy cannot occur unless you’re careless with the birth control okay now the other thing that noor just to make does which is sort of a minor thing but it is an

Important thing is it slows the frequency of release of ganado trope and releasing hormone from the hypothalamus okay and so gonadotropin-releasing hormone is actually going to trigger the anterior pituitary gland to release luteinizing hormone luteinizing hormone when this is released is going to trigger ovulation as well and so by decreasing gonadotropin-releasing

Hormone you decrease the ability of the body to release luteinizing hormone or lh that prevents the lh surge and further prevents ovulation okay so you’re just a mate is going to be the major drug that birth control is going to contain in the case where birth controls only contain one of these it’s always the progesterone analog generally there’s no reason to

Just take the the estrogen analog it’s gonna have to be the norge estimate okay because you need to trick the body into thinking that ovulations already occurred right but as i mentioned at the start of this video many birth controls are combination birth controls so in addition to the norge estimate or another progesterone analog they’re also going to contain

An estrogen analog such as ethinyl estradiol okay so that’s that’s characteristic of a combination birth control now the reason that you add the synthetic estrogen is it augments the function of the synthetic progesterone okay and the way it works is the estrogen also suppresses the release of gonadotropin-releasing hormone okay just like nor justin mate does

Okay the estrogen has no effect on tricking the body into thinking that ovulations already occurred that’s solely the job of the progesterone analog but the estrogen alog also it’s going to suppress the release of genetic trope and releasing hormone which will in turn suppress the release of luteinizing hormone and remember that luteinizing hormone the lh surge

Is responsible partly for ovulation okay in fact it’s directly what triggers ovulation and so if you don’t have an lh surge then you probably won’t have ovulation all right so hopefully this gave you a good understanding of the mechanism of combination birth control please make sure to like this video and subscribe to my channel for future videos and notifications thank you very much

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The Mechanism of Combination Birth Control By Catalyst University