Video: Female reproductive system

I'm betting we're all familiar with the common question, “Where do babies come from?” – posed by the ever curious child and dreaded by parents scrambling to provide an answer. Parenting duties aside, discussing this topic can also be daunting during a university course, but we all have genitalia and given that over 50 percent of the population have female genitalia, it's a pretty important subject to learn about. So fear not. We're here to deliver everything you need to know about the female reproductive system.

All right, so what exactly will we learn today? We are going to discuss the female reproductive organs and how they are categorized. As we go through, we will take a look at the functions of each organ as well as overall functions of the female reproductive system.

The female reproductive system consists of internal reproductive organs and external reproductive organs. Starting with the internal organs, this group consists of the ovaries, the uterine tubes, the uterus, and the vagina. Next, the external organs are composed of the vestibule of vagina, labia minora, clitoris, labia majora, and mons pubis.

Overall, the female reproductive system has several functions. These include the formation and development of gametes which are otherwise known as ova, egg cells, or simply eggs; the production of female sex hormones, estrogen and progesterone; sexual pleasure; and making reproduction possible. Fertilization and implantation of the egg and maturation of the embryo and fetus happen within the female reproductive tract. It's truly our first home.

Learning the organization of the female reproductive system and the precise function of each organ can feel laborious at first, but not to worry, we will help facilitate your understanding. So let's get started with the internal reproductive organs.

The ovaries are the gonads of the female reproductive system which means that they are reproductive glands that produce reproductive cells or gametes. These multifunctional organs are located bilaterally in the pelvic cavity. Taking a look at this image where we can see the pelvic organs in situ from an anterior perspective, we recognize how the ovaries reside posterior and inferior to the uterine tubes. In this image, we can also see the rectum posterior to the uterus, the vagina, and the pelvic bones.

Now that we've oriented ourselves, we can transition to a posterior view and understand this common illustration of female reproductive anatomy.

The ovaries are highlighted in green. As we mentioned before, each ovary produces and releases egg cells. Also acting as endocrine glands, the ovaries produce female sex hormones vital for fertility, menstrual cycle regulation, and sexual maturation of the female. Specifically, the ovaries secrete estrogen and progesterone.

Phew! Those ovaries sound really important, right? So is there something holding them in place?

Well, zooming in, we can breathe easy knowing that each ovary is suspended in the peritoneal cavity by the suspensory ligament of the ovary and the proper ovarian ligament.

Moving on to the uterine tubes, otherwise known as the fallopian tubes or oviducts, we can see their close relation to the anterosuperior aspect of the ovaries. These muscular tubes are pivotal reproductive structures as they are responsible for transporting egg cells from the ovaries to the uterus. They are also the site of fertilization of these cells.

The uterine tubes each consist of four parts that we will discuss now. First, there is the infundibulum which is the distal end of the uterine tube; that is, the end closest to the ovary. It opens into the peritoneal cavity. The infundibulum contains finger-like mucosal projections called fimbriae that extend over the superior aspect of the ovaries. When an egg cell is released from the ovary, the fimbriae waft it into the uterine tube.

Continuing in the path of an egg cell, we come to the ampulla. This is the widest and longest part of the tube and is the most common site of fertilization. Medial to the ampulla is the isthmus, which is the narrowest and most muscular part of the uterine tube. The isthmus is continuous medially with the intramural or uterine part of the uterine tubes and the intramural part communicates directly with the uterine cavity.

Now let's talk about the uterus, otherwise known as the womb. This hollow organ resides deep in the pelvic cavity and is the site for implantation of the fertilized egg and development of the embryo and fetus. The uterine wall is composed of multiple layers – the innermost endometrium which sheds during menstruation and is the usual site for implantation of the fertilized egg, and the myometrium, which is composed of smooth muscle that contracts during childbirth and menses, and the outermost layer, the perimetrium.

The entire uterus is also divided into four parts that we will review now. This uppermost rounded part is called the fundus. The body is the main part of the uterus consisting of a triangular-shaped lumen called the uterine cavity. Both uterine tubes communicate with this lumen. Just inferiorly is the isthmus which is a constricted narrow part of the uterus. Lastly, inferior to the isthmus, we have the most inferior part of the uterus – the cervix. The cervix connects the uterus and the vagina and is composed of two parts – the supravaginal part, the part above the level of the vagina, and the vaginal part, which projects into the vagina.

The passageway of the cervix is called the cervical canal which has two openings or orifices – the internal os opening into the isthmus of the uterus and the external os which opens into the vagina. In this lateral view of the pelvic cavity, you can see that the uterus is posterior and superior to the urinary bladder while anterior to the rectum. The anatomical position of the uterus is mostly commonly anteflexed and anteverted. Anteflexed means the body of the uterus is bent forward when compared to the long axis of the cervix while anteverted means the long axis of the cervix is inclined anteriorly when compared to the long axis of the vagina.

Briefly, of clinical relevance, the body and fundus of the uterus are covered by visceral peritoneum – a membrane that lines the abdominal and pelvic organs that is reflected onto the bladder and rectum. Reflected means the peritoneum doubles back on itself. This forms the vesicouterine pouch anterior to the uterus and the rectouterine pouch posteriorly.

Now let's review the outermost internal organ – the vagina or birth canal. The term birth canal tends to be reserved for labor. In this image, you can see the vagina is a fibromuscular tube inferior to the cervix of the uterus. It is surrounded by pelvic connective tissue. Transitioning to the posterior view of the vagina, we can appreciate the need for the connective tissue to be elastic. This lets the vagina expand to make childbirth possible.

Functionally, the vagina has several roles. It contributes to sexual pleasure from vaginal intercourse. It aids fertilization of egg cells by facilitating deposition and transmission of semen to the uterus. It allows for the expulsion of products of menstruation. It is a place of passage for products of conception when a pregnancy is not viable and for fetus during labor. Notably, regarding semen collection, the vaginal fornices seen here are important recesses or pocket-like areas that are conducive to retaining ejaculated semen.

Alright, let's wrap up the internal female reproductive organs where the discussion of what happens in the ovaries and their role in the menstrual cycle. No need to worry or feel intimidated here because we'll keep things simple.

So within each ovary, there are thousands of groups of cells called ovarian follicles, each containing an immature egg cell called an oocyte. Follicles undergo maturation during the menstrual cycle and highlighted in green in this image is the mature follicle, which is called the tertiary follicle. It releases its oocyte at the time of ovulation.

After ovulation, the fimbriae of the uterine tube engulfed the oocyte pulling it into the tube. It is then propelled through the tube via peristatic muscular contractions. The uterine tube is the site where fertilization takes place. In a normal pregnancy, if the oocyte is fertilized by male sperm, it will undergo the initial stages of development and travel to the uterus in three to four days before implanting in the uterine wall a couple of days later.

After releasing the oocyte, the tertiary follicle transforms into a corpus luteum. In the event of fertilization, the corpus luteum will be maintained in the ovary and secrete estrogen and progesterone to promote implantation of the embryo in the uterine wall. However, if fertilization does not occur, the ovarian follicle briefly forms the corpus luteum before shrinking and transforming into the corpus albicans, which is a small amount of fibrous scar tissue.

And that's it for the internal reproductive organs. Now let's turn our attention to the external reproductive organs.

Keep in mind that the female external reproductive organs come in multiple shapes, colors, and forms and the diagrams shown are merely representative of one variety of normal. You can refer to the website, Labia Library, as a non-exhaustive demonstration of variants as well.

First structure we need to talk about is the vulva. It's important to understand that the vulva is a term used for the entire external female genitalia and it is represented in this image. The vulva is located anteriorly in the perineum. As mentioned earlier, we'll be reviewing the main components of the vulva starting with the vestibule of vagina. We'll then discuss the labia minora, the clitoris, the labia majora, and the mons pubis.

The vestibule of vagina, also known as the vulval vestibule or simply vestibule, is an area that sits at the entry of the vaginal canal. That's exactly what is represented in this coronal perspective of the female pelvis where we can see the vestibule and the vaginal canal. Switching to this inferior perspective of the female perineum, we can see that the vestibule is located between the labia minora laterally and posterolaterally and is bound anteriorly by the posterior margin of the clitoral prepuce. Posteriorly in the vestibule, there is a depression called the vestibular fossa.

The vestibule contains the vaginal orifice or opening, the openings of the greater and lesser vestibular glands, and the external orifice of the urethra, which is the place where urine exits the urethra. It is not represented in this image, but the hymen is also part of the vulva in some people. It attaches at and covers usually partially the vaginal orifice. A crescentic hymen, shown here, is the most common shape. However, as with the rest of the external genitalia, these come in multiple variations including absent.

Let's focus on the greater vestibular glands for a moment. These glands are also known as Bartholin's glands and here we can see the openings of the ducts of these glands. These two pea-sized glands are situated at the opening of the vagina and are homologous to the bulbourethral glands in males. These glands secrete mucus that lubricates the vagina.

On our next topic, the labia minora, are two thin longitudinal folds devoid of hair which surrounds the vestibule and its contents. They are found between the labia majora and are enclosed by the pudendal cleft. The labia minora meet posteriorly in the frenulum of the labia minora. Anteriorly, each labia minus bifurcates into an upper and lower layer. The upper layer of each side unifies over the glands of the clitoris giving rise to a fold covering the clitoris known as the clitoral prepuce or clitoral hood. The lower layer of each side passes below the glands of the clitoris to form the frenulum of the clitoris.

Let's now move on to the clitoris. The clitoris is an erectile organ responsible for sexual sensations. It's rather intricate, analogous to the male penis without the urinary function and is often oversimplified in anatomic textbooks or atlases. The clitoris is situated where the labia minora meet anteriorly and is composed of the glans, the body, and the two crura. The glans is visible here while the body and crura reside underneath the surface.

The full extent of the clitoris is depicted in this image which we will use to explain this structure. Each of the two crura of the clitoris are attached along each inferior pubic ramus. The crura unite anteriorly to form the body of the clitoris. The body ascends towards the pubic symphysis and descends to become the glans. The body of the clitoris, which we can see here in cross-section, consists of two cylindrically shaped corpora cavernosa, which is a kind of erectile tissue that is also present in the crura of the clitoris.

The glans of the clitoris is composed of another type of erectile tissue which is also present in the bulbs of the vestibule, a pair of erectile structures situated on each side of the vaginal opening. In our cross-section image, we can also see the clitoral neurovasculature. The clitoris contains a rich supply of autonomic nerve endings, highly sensitive to tactile and/or sexual stimulation.

The glans is the most densely innervated part of the clitoris. The majority of innervation to this organ is delivered via the dorsal nerve of the clitoris. It's critical clinically to recognize and understand the neurovasculature to the clitoris to prevent unintended damage to these structures during surgical procedures.

If there's a minor, there must be a major, right? Yep, the labia majora are the most lateral part of the vulva and enclose the labia minora. Located posterior to the mons pubis and anterior to the perineal body, the labia majora are thick longitudinal folds of skin and adipose tissue. They remain hairless until puberty and form the lateral boundaries of the pudendal cleft. The two labia majora merge anteriorly in the anterior commission.

Finally, the last structure we want to talk about is the mons pubis. This rounded eminence located in front of the pubic symphysis consists of a large amount of subcutaneous adipose tissue and bears the most pubic hair after puberty.

Now that we've discussed the macroscopic anatomy of the female reproductive system, let's look at a common and emergent clinical correlate.

An ectopic pregnancy occurs when a fertilized egg implants and grows in a location outside of the body of the uterus. This commonly occurs in the uterine tube, referred to as a tubal pregnancy. An ectopic pregnancy can also manifest in the ovary, cervix, or peritoneal cavity, which is shown better on this lateral perspective of the pelvis. This type of pregnancy cannot proceed normally as the fertilized egg is unable to survive and the growing tissue may cause life-threatening bleeding to the mother if undiagnosed or left untreated.

All right, that wraps up our tutorial on the female reproductive system. Well done for following along. But before you go on your way, let's take some time to briefly summarize what we learned today.

We started our tutorial by discussing the internal reproductive organs. This first included the ovaries. We noted that the ovaries are the female gonads and produce egg cells along with female sex hormones. Then we talked about the uterine tubes, otherwise known as the fallopian tubes, which transport egg cells from the ovaries to the uterus.

The uterine tubes can be divided into four parts – the infundibulum is the distal end that gives rise to the fimbriae, the ampulla is the widest portion, the isthmus is the narrowest portion, and lastly, the intramural part is located within the myometrium.

We also looked at the uterus which is made up of the fundus, the body, the isthmus, and the cervix. Part of the cervix projects into the vagina. We reviewed the vagina which is a pleasure organ, receives the penis during sexual intercourse, and is the passageway for childbirth and menstruation.

With regards to the external reproductive organs, otherwise known as the vulva, we looked at the vestibule of the vagina, the labia minora which encloses the vestibule, the clitoris which is the sexual pleasure organ, the labia majora which are a pair of thick folds of skin, and finally, we looked at the mons pubis which is a rounded collection of subcutaneous adipose tissue in front of the pubic symphysis.

To conclude this tutorial, we reviewed ectopic pregnancy including how this atypical pregnancy occurs and the emergent clinical scenario that can ensue.

That's it. Excellent work everyone. I hope you enjoyed this video and happy studying!