Female Reproductive System: Internal Anatomy
- 0:05 Female Reproductive Tract
- 1:06 Ovaries
- 2:23 Uterine Tubes
- 4:54 Uterus and Cervix
- 6:27 Vagina
- 7:19 Lesson Summary
Ever wonder where a female produces her eggs or how they get from the ovary to the uterus? Find out in this lesson about the internal reproductive anatomy of females.
Female Reproductive Tract
Ahhh, the secrets of women - what guy hasn't wondered about that? Well, we aren't quite ready to reveal the mystery of a woman's heart; those are something all her own. You could take a course on sex differences of the brain - that might help you learn how women think, but we can't promise anything. What we can do is give you a glimpse of what's inside her. You know what they say; 'beauty is what's on the inside,' right? And on the inside, all women have the same reproductive structures.
So, while not as interesting as the mysteries of the mind, the mysteries of the female reproductive tract include a couple key structures:
- The ovaries, which produce the next generation
- The uterine tubes, which transport the next generation
- The uterus, which grows the next generation
Hmmm, see a pattern developing here? Let's not forget the cervix and the vagina, the doorways to the rest of the reproductive tract.
First up are the ovaries. These are small, about the size of a walnut with a lumpy appearance, and are usually off-white or yellowish in color. They are located near the walls of your pelvic cavity (that's the cavity down where your hips are), and, similar to the testes, are protected by a layer of connective tissue called the tunica albuginea. If you've learned about the testes already, you may remember that this is the same name used to refer to the connective tissue layer that covers each testicle.
Now, these tiny little structures are quite important for the future of the human race. You see, the inside of the ovary houses lots and lots of egg nests. No, not like a bird's nest, more like a nest made of cells and tissue. Each month, one of these thousands of eggs is recruited from the nest to begin its journey to become an oocyte. The nests form and the journey takes place in a specific part of the ovary called the cortex.
The cortex is located along the sides of the ovary, and it's where oocyte production occurs. In addition to the cortex, the ovary also has an area called the medulla, which is located in the center of the cortex, and that's where the arteries and veins of the ovary are found.
Okay, so now that we know why females have ovaries and what they do, let's go back to our recruited oocyte for a bit. Once the oocyte leaves the nest and has traveled through the cortex, it is ready to graduate onto its next potential pathway in life: the possibility of meeting a sperm and growing into a baby. To do this, it has to have a way to get there, right?
That's the job of our next structure. When the oocyte is released from the ovary, it is caught by the uterine tubes. These are hollow, muscular tubes whose job is to transport the oocyte from the ovary to the uterus. If you look closely, you will see that their structure changes from one end to the other. That is because they are divided into three different parts.
- The infundibulum is the expanded, funnel-shaped portion closest to the ovary. See those fingerlike projections? They contain a bunch of little tiny cilia that beat quickly, catching the oocyte as it is released from the ovary and pushing it towards the middle of the uterine tube, the portion called the ampulla.
- The ampulla is located in between the infundibulum and the isthmus. The smooth muscle layers here help push the oocyte down the tube towards the uterus.
- The isthmus is the portion closest to the uterus and connects the uterine tube to the uterine wall.
The cilia and the smooth muscles work together to transport the oocyte through the tube and towards the uterus. This is a process known as peristalsis , the wavelike movement of smooth muscle contractions often used to move objects.
Now, if the egg is going to meet up with sperm from the male, it usually happens along this pathway at the boundary between the ampulla and the isthmus. So the oocyte depends on peristalsis for transportation - transportation to increase its chances of meeting up with the male's sperm so that fertilization can occur, and then transportation to the uterus, where it will develop into a baby.
However, while the purpose of oocyte release and transport is for reproduction, most of the time fertilization does not occur, and in these cases the oocyte will simply degenerate as it reaches the end of the uterine tube.
Uterus and Cervix
Next stop: the uterus. That's the big structure in the middle. This is where the magic of life takes place, where that tiny little fertilized oocyte develops into a baby!
You see, each of the uterine tubes connects to the uterus, one on each side. Once an oocyte is fertilized it travels to the uterus because the uterus is the site of oocyte implantation. Once implanted, the uterus protects and nourishes the fertilized oocyte, which is now called an embryo.
In preparation for this, the uterus usually builds of several layers of protective tissue that are shed monthly if no implantation takes place. This shedding is what we refer to as a women's 'period' but is more correctly called menses, the monthly flow of blood and tissue from the uterus.
That brings us to our next structure. If the developing baby or the uterine tissue has to leave the uterus, it has to have a way to exit, right? That's where the cervix comes in. The cervix is actually part of the uterus. It is the part that is inferior to (or below) the main body of the uterus and provides an opening from the uterus into the vaginal canal. It's kind of like the doorway to the female reproductive tract. If something like sperm wants to enter, it has to go through the cervix, and similarly, when babies are born they exit the uterus through the cervix.
So if our cervix is the doorway to the uterus, that would make the vagina and the vaginal canal kind of like the hallway. The vagina is a muscular tube with an opening to the outside of the body at one end and the cervix at the other end. Near the opening to the outside of the body is the vaginal canal, which is partially covered by a thin piece of tissue called the hymen. This tissue is usually broken the first time one has intercourse or uses a tampon.
There are three main functions of the vagina:
- It acts as a passageway for the elimination of blood and tissue during menses.
- It acts as an insertion point for the penis during intercourse and functions to hold sperm prior to their transportation into the uterus.
- It acts as the birth canal during labor.
And there you have it, the mysteries of the female - well, at least of her reproductive tract. All of these structures are unique to the female and therefore are not found in males. They include the ovaries for gamete production, the uterine tubes for oocyte transport, the uterus for the protection and nourishment of a developing embryo and, last but not least, the cervix and vagina, which are the exit and entrance to the rest of the female reproductive tract.
Each of these structures is important. They work together to control the production of the female sex hormones, which in turn controls oocyte production, menses, pregnancy and reproductive behavior, all important parts in reproduction and creating the miracle of life.
Chapters in Biology 105: Anatomy & Physiology
- 1. Review of Inorganic Chemistry for Anatomy & Physiology... (14 lessons)
- 2. Organic Molecules (7 lessons)
- 3. Biochemistry (10 lessons)
- 4. Basic Anatomy and Cell Biology (12 lessons)
- 5. Respiratory System (13 lessons)
- 6. Cardiovascular System (18 lessons)
- 7. Blood Vessels (6 lessons)
- 8. Digestive System (15 lessons)
- 9. Urinary System (11 lessons)
- 10. The Endocrine System (17 lessons)
- 11. The Brain (8 lessons)
- 12. The Nervous System at the Cellular Level (10 lessons)
- 13. The Five Senses (11 lessons)
- 14. Muscular System (13 lessons)
- 15. Gross Anatomy of Muscular System (12 lessons)
- 16. Connective Tissue (8 lessons)
- 17. Skeletal System (10 lessons)
- 18. Anatomy and Physiology of Male and Female Reproductive... (23 lessons)
- 19. Early Development to Childbirth (22 lessons)
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