Login

Phases of The Ovarian Cycle: Overview from Puberty to Menopause

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: The Female Reproductive Axis: Coordination of the Brain, Ovaries & Uterus

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:05 The Ovarian Cycle
  • 1:49 Timing: Puberty
  • 3:13 Timing: Menopause
  • 4:03 Lesson Summary
Add to Add to Add to

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Login or Sign up

Timeline
Autoplay
Autoplay
Create an account to start this course today
Try it free for 5 days!
Create An Account

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Heather Adewale

Heather has taught reproductive biology and has researched neuro, repro and endocrinology. She has a PhD in Zoology/Biology.

Just like the human body has to grow and mature before it is ready to reproduce the female's gamete, the egg also has to grow and mature. This lesson will introduce the process through which that occurs, the ovarian cycle.

The Ovarian Cycle

Male and female gametes are needed for most animals to reproduce
Most Animals Need Gametes to Reproduce

We all know that in order for humans and most other animals to reproduce, you need a male and a female - or, more specifically, you need their gametes, the female's egg (also called an oocyte) and the male's sperm. But just like everything else in life has to grow and mature before it can reproduce, so do our gametes. In this lesson, we will learn about how the female's gamete, the oocyte, gets ready for the possibility of fertilization and reproduction. To do so, the oocyte has to grow and mature in a process known as the ovarian cycle.

The ovarian cycle is split into two parts:

1. The follicular phase, also called the preovulatory phase, refers to the parts of the cycle that occur before ovulation, just as its name suggests. It is during this phase that oocyte follicles are recruited and prepped for ovulation.

2. The second half, the luteal phase, is also called the postovulatory phase and refers to the parts of the cycle that occur after ovulation. During this part of the phase, the now-empty follicle produces hormones that are important for reproduction.

And, just as the name suggests, the ovarian cycle is cyclical - a monthly cycle, to be exact. It repeats itself, on average, every 28 days as long as the female isn't pregnant. The cycle starts with the follicular phase, which lasts 14 days, ending with the ovulation of the mature oocyte, or egg. Once the oocyte has left the ovary, the ovary then enters the luteal phase, which extends from days 15-28.

Timing: Puberty

So now that we know the basics of what the ovarian cycle is, let's talk a little bit about when it occurs. If you think back to the purpose of the ovarian cycle, you may remember that it is to recruit and mature oocytes. Now we can expand on that definition by adding 'in preparation for reproduction.'

So, putting two and two together, you may have guessed that the ovarian cycle doesn't start until the female is ready for reproduction. And what life event better to signal one is ready for reproduction than that wonderfully awkward stage of life called puberty? Puberty involves an increase in hormone activity, especially hormones involved in reproduction such as estrogens, progesterone and the gonadotropins LH and FSH.

Puberty starts in the brain when it releases increased levels of GnRH
Puberty Starts in Brain

Now, even though these are hormones of reproduction, and our organ of reproduction is the ovary, puberty actually starts in the brain. The brain starts to release increased levels of a neurohormone (that's just a hormone that's found in the brain). This hormone is called GnRH. GnRH triggers the release of other hormones, LH and FSH, from a part of the brain called the pituitary. These hormones then travel down to your ovaries, where they're involved in the activation and regulation of the ovarian cycle.

To unlock this lesson you must be a Study.com Member.
Create your account

Register for a free trial

Are you a student or a teacher?
I am a teacher
What is your educational goal?
 Back

Unlock Your Education

See for yourself why 10 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it free for 5 days!
Create An Account
Support