- [Narrator] Now switching over to the female side of things. The ovaries are the primary organs. Now the ovaries release oocytes. Those are the eggs, the immature eggs. And the ovaries will also help secrete the hormones estrogen and progesterone. From the ovaries, we have these tubes called uterine tubes, you might know more about term of fallopian tube. This is what will help to carry these oocytes, or immature eggs from the ovaries down towards the uterus. But another reason why they are important is if fertilization's going to occur so if the egg will be fertilized, it'll typically occur in the upper third of the uterine tube so that first upper third there is where the sperm would typically run into the egg or oocyte. From the uterine tubes, or the fallopian tubes, we can head down to the uterus. The uterus is going to be a hollow organ. The walls are primarily filled with smooth muscle. And the purpose of the uterus is really to help house, develop, and be a place for the egg to grow. This only occurs if the egg was fertilized back up in the uterine tubes. Now inside the uterus, we're going to have three layers. The most internal layer is called endometrium. The endometrium, or the inside, is where that fertilized egg can implant. It's going to be a place where the egg can be protected, where it can grow, where it can be nurtured. But if there is not implantation, that means there was no fertilization then part of this endometrium was removed during the menstrual flow. The middle layer is the myometrium. Now this middle layer is all muscle, tons and tons of smooth muscle. It can expand during pregnancy, but this is what really constricts during labor. This is what helps to force that developing fetus, or that infant, out at birth. Now the third layer is the external layer, just pretty much some connective tissue so we're gonna skip over that one. Now we have the cervix. The cervix isn't really a layer, it's more of a region, or an area. The cervix is going to be the opening at the end of the uterus. It's the opening that allows the sperm to enter into the uterus and eventually up to the uterine tubes. But it's also the same opening that the fetus will exit out of during birth. So we have the cervix, the end or opening end of the uterus. Once we pass the cervix and leave the uterus, the next structure is going to be vagina. Now the vagina is the birth canal. It's where that developing fetus will pass through on the way out of the female body. But the vagina is also the organ for sexual intercourse. It's the entryway of how the sperm enter into the female system. And the very outside surface is the eternal genitalia. You have the labia majora and labia minora. These are the folds of skin that will actually cover and close up the vaginal canal. The clitoris is the small, sensitive organ located just anterior, just in front of the opening to the vagina. The purpose of the clitoris is for stimulation during sexual intercourse. So here we have a lateral view. We're looking from the outside edges towards the center of a cut through cross section. What you can see is you have the vertebral column, you have the pubic bone, both parts of the skeletal system. Urinary bladder, urethra parts of the urinary there. Rectum and anus, parts of the digestive. We'll start with the ovary going into the fimbriae, also fingerlings. The ovary is where all those undeveloped oocytes, or eggs are being housed. It's where typically a monthly cycle, one, two, or three, of the oocytes will be matured. Once ovulation occurs, you're gonna see how the fimbreae, those little finger-like structures that are going around the ovary, those fimbriae are gonna help steer or guide that mature egg into the uterine tube. So the fimbriae help to guide it to the uterine tube. It then travels on down to the uterus, the uterus here is shown as several layers. Again, we have that endometrium, which gives that nice location for the egg, or oocyte to implant, but only if fertilized, and tons and tons of smooth muscle. The cervix is the opening that leads out of the uterus. And then we have the vaginal canal, leading out of the female's body. External structures, you can see the clitoris, labium minora and labium majora. Now labium minora and majora are the two folds of skin. You're only seeing one on each side here, because the other side of the body is removed from this view. There would be a labia majora and labia minora on both sides. The clitoris you'll see is right towards the front, or the anterior section there. It's in front of the urethral opening, as well as in front of the vaginal opening. Here we have an anterior view of a female reproductive system. You know it's the fimbriae, those little finger-like projections that are going around the ovary. But what's interesting is those fimbriae, or those little finger-like projections, they actually don't touch the ovary. What they're doing is creating an environment around it that helps act like a vacuum, helps to pull the ovulated eggs up into the uterine tube. So we have the ovary, we have the uterine tube. Which that leads down into the uterus. And we've already mentioned the two layers, the endometrium and myometrium. Remember the endometrium is meant to basically nourish, to protect a fertilized egg. While the myometrium, the muscle, that is meant to aid in contraction during labor, helping with the childbirth process. Cervical canal, that is the opening that leads into the vaginal canal, or you think of it as the exit out of the uterus. The cervix itself is gonna be right at the very end of the cervical canal. Typically the cervix is gonna be filled on the inside, where that cervical canal is, with mucous, it helps protect the female body, prevent any bacteria or anything from coming up into the female body. And then we have the vaginal canal, leading from the cervix to the external parts of the body. Now here is an external view of a female reproductive. What you notice is we have the vaginal opening, and a little above that in this picture, which means more towards the front or anterior, is the urethral opening. Even more anterior, or in front of that, is the clitoris. Covering on both sides is the labium minora, you can see both flaps of skin there, can actually cover and seal up the vaginal opening, helping protect it. And then we have the labium majora, which are even larger folds of skin. It can help to close up and seal up the vaginal opening, providing protection from foreign particles, from bacteria, from viruses. If we move up into the mammary glands now. Technically mammary glands are actually sweat glands. So the tissue inside of a female's mammary glands is the same exact tissue as any common old sweat glands. The difference is, though, the mammary glands have been slightly modified, and this modification in allowing production of milk instead of the production of sweat. So they're basically specialized for lactation, production of milk. But there are two main hormones that are going to control lactation. You have prolactin, which is helping with milk production, and you have oxytocin, that's what's helping to stimulate the contractions that actually inject the milk, forcing the milk out of the mammary tissue. So prolactin and oxytocin. And both are gonna be stimulated, or helped out, by the suckling action of an infant. So here we have both an anterior, or front view, and a lateral, or side view, of the mammary tissue. You can see how the skin has been cut away to reveal the muscle, the fat, and all the mammary tissue below it. Go a lot deeper, you can notice that behind the mammary tissue is where the ribs and your lungs are found. So we have all these, in this particular view, brown spheres, now brown was just the color the artist picked, it's not the real color, but the spheres are Those are gonna be the milk-producing lobules. They produce all these little spheres inside the breast, inside the mammary tissue. The milk is then carried through ducts, which are leading out to the nipple. So you have production inside these lobules, these round structures, which then secrete the milk into the ducts, which transport to the nipple for the infant to feed on.