- [Instructor] The human sexual response is actually similar but yet at the same time different in males and females. Both males and females will have the same idea of excitement, a plateau, the orgasm, and resolution. But the difference is in the male sexual response, the orgasm is a point marked by ejaculation of semen. Once the ejaculation of semen has concluded, the male goes into refractory period. A period where he will not really have any sexual response at that point. While on the female side of things for sexual response, the female orgasm is more marked by a rhythmic muscular contraction. These rhythmic muscular contractions are actually meant to take the ejaculated semen and help pull it towards the uterine cavity. By pulling it towards the uterine cavity is the females body's way of trying to bring the sperm up into the uterus, so that it can travel up into the uterine tubes for fertilization. Remember the whole idea of the human sexual response is for procreation, egg and sperm fertilizing for an embryo. With fertilization is looking at having had several hundred million sperm per ejaculates, they're all trying to find that potentially one ovulated egg. Now with all those sperm, that huge number, only one sperm will actually penetrate the egg. Now the picture you see here you can see dozens if not hundreds of sperm all around this egg. But yet only one will be allowed inside. The way it works is, once one's sperm penetrates the outer layer of the egg the egg goes through a chemical reaction, which actually seals the entire outside surface, making it impossible for any other sperm to enter. Now is there the rare chance that you get two sperm in at the exact same time? Yes. That's a very unusual, very rare circumstance. So we're talking about fertilization, also mentioned about birth control methods. Now birth control methods range from very simple to not have intercourse, to very complicated with surgical sterilization. There's a whole series of methods in between. In the case of a surgical sterilization, the male side of things, is a vasectomy. The vasectomy will actually go in and cut the ductus deferens or the vas deferens. But it's important not just to cut but also to seal the two ends. What this causes to occur is the sperm that's produced in the testes now cannot leave the testes or epididymis. Therefore if they can't leave there's no way for the sperm to enter into the semen or the ejaculate. In the case of a female, it's tubal ligation, or getting tubes tied. What happens now is the uterine tubes are being cut and both sides are tied off. This prevents an oocyte, or an egg, from leaving the ovary and actually reaching the uterus, just is blocked or stopped. Now in both these situations vasectomy and tubal ligation, sure is a 99.8 or something like that percent successful. There's always those unusual circumstances where the sealing of the ductus deferens or the tying of the uterine tubes comes undone. And somehow the two ends end up getting back together a la for one continuous tube. Now the chances of that are very very small, but that's why it's not 100% perfect. Now the one that is 100% though, a hysterectomy in females. In the case of a hysterectomy the oviducts are physically sealed off and the uterus can be removed. So this point there is no way for a pregnancy to occur. One more common methods though is birth control pills. Most the birth control pills are dealing with a kind of combination of synthetic progesterone or synthetic estrogen. The idea is to keep those levels higher, preventing FSH and LH. If you prevent FSH and LH, there's no ovulation. And if there's no ovulation obviously there's no egg to fertilize. You also have some hormones being injected, so these injections, instead of being a pill a day, injections are once a month, or once every three months, or you can now push it once every six months. The patch. It's a simple patch to be worn throughout a cycle period. So the Ortho Evra patch is one example. It might be worn for 30 days, now looking into patches that are going for 90 days this point. Again it's a slow release of hormones entering through the skin. There's a vaginal ring. Now this vaginal ring, is basically again releasing hormones but now within the body. So all these are dealing with hormones, but all in different methods. Some other birth control methods are things like IUDs, or the intrauterine devices. Now these intrauterine devices are typically actually small plastic inserts, they might have a little bit of metal in them sometimes. But the idea is this IUD is actually creating a small mount of inflammation inside the uterus. By creating this small amount of inflammation it actually prevents the fertilization, because the uterus itself is not preparing fertilization. Some of the IUDs also have small amounts of hormones and this very small trickle of hormone can help prevent fertilization. There are diaphragms, or called cervical caps. Now the diaphragm or cervical cap is actually meant to prevent the sperm from entering through the cervix. So it's literally a cap that goes over the cervix, preventing any entry. Spermicides. The spermicides are literally a chemical that is meant to kill sperm. So obviously kill a sperm, there's no way of having them reach the uterine tubes. Condoms. The condom is both male and female. Male condom is meant to trap the sperm, or trap the ejaculates before it even really leaves the male system to fire. So to trap it right at the end of the male penis. While the female condom is gonna be inserted into the female vaginal canal it's also meant to catch or trap any sperm, preventing it from leaving the vaginal canal. There's a few other natural alternatives. There's different methods of withdrawal, or rhythm method. Now are any of these 100% foolproof? No. Everyone has practiced, everyone takes certain amount of knowledge of how it works. The problem with a lot of the natural methods is even with the natural methods, sometimes the ovulation cycle might be a little bit off a day or two early. It's very hard to know that. In the case withdrawal, the idea is to remove the penetration of the penis before the actual ejaculate occurs. Well there's also a little bit of a pre-ejaculate, that mucus from the bulbourethral gland. Sometimes that can contain some sperm. And that can starts quite a bit before the actual orgasm. There are these morning after pills. Well if this is if nothing was used the nothing before, or the day before, whenever it happened, and all of a sudden realizing that this might be a problem because ovulation is happen at the same time. The morning after pill is meant to prevent or stop any potential fertilization. There's the idea of abortion. Now there's early stage and late stage abortions. Now this becomes very controversial from state to state and person to person. But in the case of abortion, that is when the pregnancy has started so the fertilization has occurred but then there's a mesh that goes in and removes, or terminates the pregnancy. In the future, well who knows what's happening. They're looking at vaccines that cause birth control, looking at male birth control pills, ways of preventing the actual production of sperm. Now are either of these ones viable for now? No, but there's things that are being looked at. Some possibilities that might be happening. But on the other side, sometimes there's problems conceiving. Where a couple may want to actually conceive a child, but they can't, the idea of infertility. Now there's many different causes of infertility. On the male side of things, it could be the number of sperm are just too low. The quality of the sperm are not there. Maybe they're not as motile as they should be, they can't move as easy. Maybe they're partially defective, the actual tail is not moving properly. Then there's the idea of pelvic inflammatory disease. It can cause scarring, it can cause a blockage of the oviducts or the uterine tubes there, could have unusual levels of FSH or LH. If they're not increased at the right times it would not trigger ovulation to occur. Irregular menstrual cycles. So instead of each month having a 28 day cycle, or 29 day cycle, sometimes it's longer, sometimes it's shorter, making it very hard to conceive and know what's going on and what's occurring. Endometriosis, decreased reproductive capacity, miscarriage, I mean the list goes on and on and on. Unfortunately there is no one answer, one easy way to figure out why a couple is infertile. If a couple is infertile, through their medical practice they'll go through the doctor and go through tests, go through different ideas of what could be causing it. Sometimes it can be resolved. Unfortunately, sometimes it can't be. Now some ways of enhancing fertility. There's the possibility of artificial insemination. In this case sperm are being inserted or implanted into the female system, allowing the sperm hopefully to find an oocyte or egg. There's in vitro fertilization, where the oocytes, or eggs, are taken from a female, fertilization's occuring outside the body in a test tube. Those fertilized eggs are then put back into the female so she can have them in the uterine lining and carry them through gestation. There's GIFT, or gamete intrafallopian transfer. Now in this case unfertilized eggs as well as sperm are both placed right into the uterine tube, or the fallopian tube. This allows the actual fertilization to still occur within the female body just aiding by making sure both parts, the egg and sperm, are in relatively the same location. And we have ZIFT, or zygote intrafallopian transfer. In this case, you have a fertilized egg that's being placed back up into the uterine tube, or the fallopian tube. So instead of taking that fertilized egg and putting it into the uterus and implanting it, it's going back up into the uterine tube allow it to naturally leave the uterine tube and hopefully implant in the uterine lining. There's also other fertility enhancing drugs. These drugs are meant to increase amounts of sperm, or increase the development of eggs. The idea is to create a better chance of having egg and a sperm come together. There's a probability of surrogate motherhood. Now the case of a surrogate, that's another female that is carrying the fertilized egg and helping to carry it through gestation.