Menstrual Cycle Phases | Female Reproductive System | Follicular Luteal Proliferative Secretory

Summary

In this educational video, Sarah Thread Sterner explains the menstrual cycle, focusing on its 28-day duration and the phases: follicular, ovulation, and luteal. She emphasizes the hormonal changes, particularly FSH and LH, which drive the cycle and prepare the body for potential fertilization. The video also covers uterine changes, including the menstrual, proliferative, and secretory phases, and how they support the cycle's reproductive goal. Viewers are encouraged to take a quiz for review and explore related videos in the series.

Takeaways

• 📅 The typical menstrual cycle lasts for 28 days, with ovulation occurring around day 14.
• 🌱 The primary purpose of the reproductive cycle is to prepare the body for potential fertilization and pregnancy.
• 🔍 Nursing students should focus on understanding each phase of the cycle, the hormones involved, and their timing.
• 🌼 The ovary undergoes three phases: follicular, ovulation, and luteal, while the uterus experiences menstrual, proliferative, and secretory phases.
• 🔗 The follicular phase (cycle days 1-13) involves maturing a follicle for egg release, facilitated by hormones like FSH and LH.
• 📈 Estrogen levels rise as the follicle matures, signaling the body that the egg is getting ready for ovulation.
• 💉 The LH surge triggers the release of the egg from the follicle, which then becomes the corpus luteum, secreting progesterone and estrogen.
• 🩸 The menstrual phase (cycle days 1-6) involves shedding the endometrium, preparing for a potential pregnancy.
• 🌡️ Basal body temperature can dip before ovulation and rise afterwards, which can be a sign of ovulation.
• 🚫 If fertilization does not occur, the corpus luteum degenerates, leading to a drop in progesterone and estrogen, and the cycle restarts.
• 🤰 If fertilization occurs, the corpus luteum continues to function until the placenta takes over, maintaining progesterone and estrogen levels for the pregnancy.

Q & A

What is the typical length of a woman's menstrual cycle?

A typical woman's menstrual cycle is 28 days.

When does ovulation occur in the menstrual cycle?

Ovulation occurs at the midpoint of the menstrual cycle, which is around day 14.

What are the three phases of the ovarian cycle?

The three phases of the ovarian cycle are the follicular phase, ovulation, and the luteal phase.

What is the role of the follicular phase in the menstrual cycle?

The follicular phase prepares a follicle to release a mature egg that can be fertilized.

How do hormones play a role in the development and release of an egg during the follicular phase?

Hormones such as FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone) stimulate the growth and maturation of the follicle, leading to the release of a mature egg during ovulation.

What is the LH surge and why is it significant?

The LH surge is a massive peak of luteinizing hormone that signals the egg is ready to be released from the follicle, allowing it to potentially be fertilized.

What happens to the follicle that released the egg during ovulation?

The follicle that released the egg turns into a structure called the corpus luteum, which plays a role in secreting progesterone and estrogen to prepare the endometrium for potential implantation.

What are the three phases of the uterine cycle and how do they correspond to the ovarian phases?

The uterine cycle has three phases: the menstrual phase, the proliferative phase, and the secretory phase. These correspond to the follicular, ovulation, and luteal phases of the ovarian cycle, respectively.

Why is the menstrual phase significant in the uterine cycle?

The menstrual phase is significant because it involves the shedding of the endometrium, preparing the body for a new cycle in case fertilization does not occur.

What happens if fertilization occurs during the luteal phase?

If fertilization occurs, the corpus luteum continues to secrete progesterone and estrogen to support the pregnancy until the placenta takes over, which happens around 8 weeks into the pregnancy.

What is the significance of the secretory phase of the uterine cycle?

The secretory phase prepares the endometrium for the potential implantation of a fertilized ovum. During this phase, the endometrium becomes receptive to implantation due to the influence of progesterone and estrogen.

Outlines

00:00

🌱 Introduction to the Menstrual Cycle

Sarah Thread Sterner introduces the topic of the video, which is the menstrual cycle, specifically focusing on the woman's reproductive cycle. She mentions that this video is part of a maternity review series and encourages viewers to check out other videos in the series for a comprehensive understanding. The video aims to guide nursing students through the menstrual cycle, emphasizing the importance of understanding each phase, the hormonal changes, and their timing. Sarah outlines the typical 28-day menstrual cycle, highlighting ovulation at day 14, and explains the purpose of the cycle, which is to prepare the body for potential fertilization and pregnancy. The video then delves into the ovarian changes, detailing the follicular phase that occurs from cycle days 1 to 13, focusing on the maturation of a follicle for egg release.

05:01

🔍 Hormonal Changes During the Menstrual Cycle

This paragraph discusses the hormonal changes that occur during the menstrual cycle, particularly the role of estrogen. As the follicle matures, estrogen levels rise, leading to a negative feedback loop that causes a temporary dip in FSH and LH. However, as the egg matures and is ready for release, estrogen levels peak, triggering a positive feedback loop that results in an LH surge. This LH surge is crucial for the release of the egg from the follicle. The paragraph also explains the transformation of the ruptured follicle into the corpus luteum, which plays a vital role in secreting progesterone and estrogen to prepare the endometrium for potential implantation. The discussion also covers the fertile window for women, which is around the last five days of the follicular phase and the first 24 hours post-ovulation.

10:02

🌡 Uterine Changes and Ovulation

The paragraph explains the uterine changes that correspond with the ovarian cycle. It starts with the menstrual phase, which occurs from cycle days 1 to 6, where the endometrium sheds its functional layer due to the drop in progesterone and estrogen levels. The next phase is the proliferative phase, from cycle days 7 to 14, where the endometrium rebuilds in anticipation of a fertilized egg. This rebuilding is facilitated by estrogen from the maturing follicle. The paragraph also discusses the impact of estrogen on cervical mucus, making it more sperm-friendly to facilitate fertilization. The ovulation phase is then detailed, explaining the release of the egg after the LH surge, its journey into the fallopian tube, and the brief lifespan of the ovum. It also mentions the significance of basal body temperature changes as an indicator of ovulation.

15:03

🌕 The Luteal Phase and Potential Pregnancy

This paragraph covers the luteal phase, which spans from cycle days 15 to 28, and the corresponding secretory phase of the endometrium. It explains the role of the corpus luteum, formed from the follicle that released the egg, in supporting potential pregnancy by secreting progesterone and estrogen. These hormones prepare the endometrium for implantation and maintain the necessary environment for a fertilized ovum. The paragraph also discusses what happens if fertilization does not occur, leading to the disintegration of the corpus luteum and the start of a new cycle. In contrast, if fertilization occurs, the corpus luteum remains active, supported by the embryo's release of HCG, which prevents its degeneration. The corpus luteum continues to function until the placenta takes over at around eight weeks, after which it is no longer needed.

📝 Conclusion and Resource Invitation

Sarah concludes the video by inviting viewers to test their knowledge on the menstrual cycle through a free quiz available on her website. She also encourages viewers to check out other videos in the series and to subscribe to her YouTube channel for more educational content.

Keywords

💡Menstrual Cycle

The menstrual cycle is a roughly 28-day process that occurs in the female reproductive system, preparing the body for potential pregnancy. In the video, Sarah Thread Sterner uses this term to describe the cycle's various phases, including menstruation, ovulation, and the luteal phase. It's central to the video's theme as it sets the stage for discussing the reproductive cycle's intricacies.

💡Ovulation

Ovulation is the release of a mature egg from the ovary, typically around day 14 of the menstrual cycle. It is a critical event in the menstrual cycle and is highlighted in the script as the midpoint of the cycle. The video explains that ovulation is when the egg is released into the fallopian tube, ready for potential fertilization, which is a key aspect of the reproductive process.

💡Follicular Phase

The follicular phase is the first phase of the ovarian cycle, occurring from cycle day 1 to 13. It involves the maturation of the follicle containing the egg. The video script mentions that the goal of this phase is to prepare a mature egg for release, which is essential for understanding the preparation for ovulation.

💡Luteal Phase

The luteal phase follows ovulation and lasts until the start of the next menstrual period. It is marked by the formation of the corpus luteum, which is responsible for producing progesterone to support the uterine lining for a potential pregnancy. The video script uses this term to explain the post-ovulation phase, emphasizing the role of hormones in preparing for implantation.

💡Hormones

Hormones such as FSH (Follicle Stimulating Hormone), LH (Luteinizing Hormone), estrogen, and progesterone play a significant role in regulating the menstrual cycle. The script discusses how these hormones interact to stimulate follicle growth, trigger ovulation, and prepare the endometrium for implantation. Understanding these hormones is crucial for grasping the video's discussion on the menstrual cycle.

💡Endometrium

The endometrium is the lining of the uterus that builds up in response to hormonal changes during the menstrual cycle. If fertilization occurs, it provides the necessary environment for the embryo to implant and grow. The video script describes the endometrium's preparation during the proliferative phase and its role in potential implantation.

💡Corpus Luteum

The corpus luteum is a temporary endocrine structure that forms from the ruptured follicle after ovulation. It secretes progesterone, which helps maintain the uterine lining for a potential pregnancy. The script explains that if fertilization does not occur, the corpus luteum degenerates, leading to the start of a new menstrual cycle.

💡Fertilization

Fertilization is the process where sperm meets and combines with the egg to form a zygote. The video script mentions that fertilization typically occurs in the fallopian tube and is a pivotal event in the reproductive cycle. It is the goal of the menstrual cycle, as the body prepares for this event.

💡Menstrual Phase

The menstrual phase is the shedding of the endometrium, which results in bleeding. It occurs at the beginning of the cycle, from cycle day 1 to 6. The script uses this term to describe the start of the cycle, where the body clears the endometrium in preparation for a new cycle.

💡Proliferative Phase

The proliferative phase is part of the uterine cycle, occurring from cycle day 7 to 14. It is marked by the rebuilding of the endometrium in anticipation of a fertilized egg. The video script explains that estrogen from the growing follicle stimulates this rebuilding process, which is essential for potential implantation.

💡Cervical Mucus

Cervical mucus is a fluid produced by the cervix that changes in consistency throughout the menstrual cycle. The script mentions that estrogen affects the cervical mucus, thinning it to become more sperm-friendly during the fertile window. This change facilitates sperm's journey towards the egg for potential fertilization.

Highlights

Introduction to the menstrual cycle and its significance in reproductive health

The menstrual cycle is typically 28 days with ovulation occurring at mid-cycle

The goal of the reproductive cycle is to prepare for potential fertilization and pregnancy

Ovarian changes occur in three phases: follicular, ovulation, and luteal

Uterine changes occur in three phases: menstrual, proliferative, and secretory

The follicular phase involves maturing a follicle for egg release

Hormones play a crucial role in the development and release of the egg

The LH surge triggers the release of the egg from the follicle

The corpus luteum forms after egg release and is essential for potential pregnancy

The menstrual phase involves shedding the endometrium if pregnancy did not occur

The proliferative phase rebuilds the endometrium in preparation for a fertilized egg

Estrogen from the maturing follicle thins cervical mucus to facilitate sperm migration

Ovulation occurs 24 to 36 hours after the LH surge

The luteal phase involves the secretory phase of the endometrium preparing for implantation

If fertilization occurs, the corpus luteum continues to secrete progesterone and estrogen

The cycle restarts if there is no fertilization, with a drop in progesterone and estrogen

Human chorionic gonadotropin (hCG) from the embryo prevents the corpus luteum from degeneration

The placenta takes over hormone production at around 8 weeks, signaling the end of the corpus luteum's function

Encouragement to take a quiz for self-assessment and to subscribe for more educational content

Transcripts

hey everyone it's sarah thread sterner

sorry and calm and in this video I'm

going to be going over the reproductive

cycles specifically the woman's

menstrual cycle this video will be part

of an in klux review series for

maternity so if you're studying this

section be sure to check out my other

videos in this series and as always in

the description below or at the end of

the video you can access the quiz to

review your knowledge on this material

so let's get started okay behind me I

have the whole menstrual cycle laid out

for you and what I want to do is I'm

going to walk you through it by cycle

day so you can understand what is going

on now as a nursing student what you

specifically want to pay attention to

during this lecture because it's things

ass on your exam are the following you

want to pay attention to each phase what

is happening in that phase and when that

phase is occurring specifically those

cycle days then you want to pay

attention to hormones because tests Club

to ask about the hormones like the role

of the hormone what it's doing to the

body so first let's look at what's going

on okay a typical woman's menstrual

cycle is 28 days so here we have our

timeline 1 to 28 and mid cycle is when

ovulation occurs so that is day 14 now

the whole roll the whole goal of a

reproductive cycle is to reproduce so

what the body is doing it's taking your

ovaries and your uterus they are working

together in case an egg is fertilized

and you have the development of a baby

that is the whole goal and if that

doesn't happen then the cycle will start

all over again which monthly cycles

women have monthly cycles so that is

what why all this is happening and what

is going on so what happens is that you

will have ovary changes and changes in

the uterus and E

Faye's each each stage has three phases

the ovary will have three phases the

follicular ovulation and luteal and then

your uterine will have three phases the

minstrel the proliferative and the

secrete Ettore now some of these phases

overlap with each other with a like with

a follicular will overlap with the

minstrel and proliferative and then

ovulation will happen and then the

luteal and the secrete Ettore will

overlap together because as you're going

to see these phases are actually helping

each other what's happened with the

changes that are going on in the ovaries

is actually helping the uterus get

prepared for that potential baby that

may be formed so let's start with

ovarian changes okay we have follicular

follicular faith' happen cycle days 1

through 13 and the whole goal of the

follicular stage is to prepare a

follicle to be released a mature egg let

the name help you for each stage so

follicular follicle that is the big goal

of the ovary it wants to mature a

follicle in the egg to be released so it

can be fertilized and implant in the

endometrium so what happens what is a

follicle ok you have two ovaries you

have your right ovary and your left

ovary and you have little fluid-filled

sacs in each ovary lots of them a woman

is born with lot of them and they

contain little immature eggs and what

happens is that your body will release

hormones to cause some of those

follicles to mature and then you'll

release it during ovulation so the body

is doing that during the cycle so how

does it do it okay your hypothalamus it

will release gonna tropen

gonadotropin-releasing hormone which

will cause your anterior pituitary gland

to release follicle stimulating hormone

also called FSH and luteinizing hormone

LH and these two hormones play a huge

role in getting that egg

developed and released so what happens

is whenever your ovary senses the

anterior pituitary gland releasing FSH

it starts to stimulate those follicles

to grow

now several follicles will start to grow

but only one will mature into what's

called a graphing follicle crabbin

follicle is the mature follicle that

will release the egg and all those other

follicles will die they will not release

an egg now as this follicle grows and

gets bigger and more mature you will

notice if you're charting hormones that

estrogen will start start increasing

because that follicle is releasing

estrogen and whenever estrogen is

released it's slowly going as that egg

maturing you will have a negative

feedback loop from your hypothalamus to

the ovary which is going to cause a

little dip in FSH and luteinizing

hormone because it's signaling to your

body

the estrogen rises is that that egg is

maturing so your body doesn't really

need all the FSH and LH right now

because that egg is doing its job so

you'll have a slight dip but then as

that egg matures and it's ready it's

ripe it's ready to come out you will

have that massive peak of estrogen

because it's signaling that egg is ready

whenever you have that massive peak of

estrogen you will have a positive

feedback loop which is going to cause

your anterior pituitary gland to release

a massive amount of luteinizing hormone

called the LH surge LH plays a huge role

in getting that egg out of that graph

and follicle to go into the fallopian

tubes to possibly get fertilized so LH

is rolled is the cause the egg to be

released to mature and it does this

whenever you get that huge surge it's

going to break that wall of that graph

and follicle that has that much

egg and that eggs want to come out of

there and then it's going to call that

follicle that released that egg that

grass and follicle to turn into a very

important structure called the corpus

luteum now here in the luteal phase you

will see what the corpus luteum does it

plays a role in secreting progestogen

progesterone and estrogen and what those

hormones do is it's going to make your

body your endometrium specifically

receptive for potential implantation of

a fertilized ovum so that's what it's

going to do now after you had this LH

surge about 24 to 36 hours after that

surge the egg will be released so you

have the surge then a little bit later

the egg will be relief now the most

fertile days for a woman are about the

last five days of the follicular phase

and in 24 hours after ovulation

so about cycle days 9 through 16

depending on when the woman ovulate and

everything because this stuff is not

clear cut and dry every woman varies so

about 9 to 16 days of the cycle is

whenever she is fertile because remember

and your LH surge happens 24 to 36 hours

and then the eggs release so typically

the LH surge can happen days 11 through

13 and then you have the release of the

egg and sperm if a sperm is present it

can live in the reproductive tract in

ideal conditions up to five days so it

can be there and hanging out until that

egg is released now corresponding with

your follicular phase remember we got

some uterine changes going on and the

first phase of the uterine cycle is the

menstrual phase and this is cycle days

one through six this is when the woman

will have bleeding and

she is shedding a layer of the

endometrium and this layer is called the

stratum function Alice of the

endometrium and what's happened is that

lot last cycle pregnancy did not occur

so the protest region and estrogen

levels dropped that caused the body to

cycle all this back over so hypothalamus

releases gonadotropin-releasing hormone

then causes the anterior pituitary gland

to release FSH LH which is going to

start stimulating those follicles and

the menstrual phase is happening during

the follicular phase all this is working

hand-in-hand so after about 1 to 6 days

we will go into the proliferative phase

and this is cycle days 7 through 14 so

here in the menstrual phase she shed the

layer now the goal is to rebuild the

stratum function Alice in case the egg

is fertilized and it needs a place to

implant so it can grow which is in the

endometrium so it will start rebuilding

how does it rebuild it rebuilds with due

to estrogen being secreted and where as

estrogen being secreted from that

growing follicle that's fixing to

release the egg because it knows hey a

mature egg is coming we've got to get

ready we've got to rebuild this layer in

case it implants so it's working hand in

hand and also that estrogen will cause

you know the layer to rebuild but it

also will affect the cervical mucus will

cause the cervical mucus to thin become

more sperm friendly which a sperm does

present at the thin mucus will allow it

to migrate easier easier to the

fallopian tubes for potential

implantation

okay so we've had our LH surge we're now

on day 14 and this is the ovulation

phase of the ovarian space so we have

ovulation the egg is released after LH

surge now the ovum it's now called an

ovum it's released into the

- neil cavity then it's swept into the

fallopian tube with the help of the

fimbriae the fimbriae have cilia on them

and these will cilia act like little

fingers and move in a wave type motion

and whenever that ovum is released from

that ovary into the peritoneal cavity

the fimbriae cilia get that ovum and

sweep it in to the fallopian tube so it

can get fertilized and the egg will only

live for 24 hours and then it

disintegrates now a woman if she's

charting her basal body temperatures she

may notice a dip in basal body

temperature and then around ovulation

and increase 0.4 to 1 degrees Fahrenheit

now if sperm is present to fertilize the

most common site of fertilization I

would remember this is the em and put em

Pugh lobe of the fallopian tube the

ampulla is most commonly where the sperm

and the egg will meet up and

fertilization will occur now so let's

move to day 15 through 28 rest of our

cycle we're in the second half of our

cycle we just did the first half we had

our midway point of ovulation now we're

in the last part of it okay it's called

the luteal phase and this is cycle days

15 through 28 it also corresponds with

the uterine phase phase changes which is

the secrete Ettore which is 15 through

28 as well and again you're going to see

they're working hand-in-hand because the

whole goal of this whole face is to

prepare the endometrium for potential

implantation of this hopefully

fertilized ovum but if it doesn't there

isn't any fertilization of that ovum

what will happen is that our cycle will

restart again and we'll come all the way

back over here and I'll just repeat

itself ok so what's happening here is

that our corpus luteum has formed

remember it's formed from that follicle

that released the egg and this is going

to

act as a temporary endocrine structure

that is going to help support pregnancy

it is very very interesting how it works

so I'm the endocrine what is going to

release is a lot of progesterone which

is going to play a role in this credit

or e phase of the endometrium which um

it will cause the endometrium to be

receptive for implantation of that

fertilized ovum and it stimulates

estrogen production which are your two

main hormones that keep pregnancy viable

and going good so your corpus luteum

will stay in place for 14 days and if

there was no pregnancy at all and it

will disintegrate and turn into the

corpus albicans now what will happen is

because your corpus luteum is secreting

progestogen and estrogen that's its goal

and you have no FSH and LH because that

negative feedback loop it's suppressed

that because we don't want that if we

have that or menstrual cycles going to

start over and if we have a fertilized

ovum we don't want that because we need

progesterone and estrogen so if it dies

you're going to have a major drop in

progesterone and estrogen and the cycle

is going to start all over LH and FSH is

going to come back now let's say that

fertilization did occur well the corpus

luteum will stay in place because it has

a very important job of keeping that

progesterone and estrogen in the system

so that fertilized egg can implant into

the endometrium so what will happen what

causes it to stay in place is that the

embryo will start to release HCG which

is human chorionic gonna troponin

which is what pregnancy tests pick up

and this prevents the corpus luteum from

dying so it will stay in place and the

corpus luteum will stay in place until

the placenta takes over and your

placenta produces massive amounts of

progesterone and estrogen to keep the

pregnancy and it will take over the

placenta will take over at about 8

time and then your corpus luteum has

done its job and it will die so that is

the menstrual cycle now be sure to go to

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