0:00 Adamanda Hasirugan, Biology and Medicine videos. Please make sure to subscribe, 0:04 join the former 0:05 group for the latest videos. Please visit Facebook, Adamanda Hasirugan. Please 0:08 like, and here you can 0:09 also ask questions, answer questions, and post some interesting things, 0:12 including fireworks, please. 0:13 And you can also change the quality settings to the highest one for better 0:15 graphics. 0:16 In this video, we're going to talk about the reproductive system, the human 0:20 productive system, 0:22 which is not essential, really, for homeostasis, but it's essential for reprodu 0:28 cibility to make 0:29 babies and for generations to come. 0:32 Now, the male consists of the six chromosomes, X and Y. So X and Y are the male 0:42 six chromosomes. 0:42 All male have this. The female have an X, X, X chromosome. All females have 0:47 this. 0:47 Now, what happens when making a baby is that two gametes combine, one from the 0:56 male and one from 0:56 the female. The male gamet is known as a sperm, and the sperm can either carry 1:01 the X or the Y 1:03 six chromosome. The female gamet is known as the ovum, and it always has the X. 1:08 And so when these two fuse together, this process is known as fertilization, 1:15 which will then essentially cause the female to become pregnant. 1:21 Now let's look at the organs, the sex organs of both the male and female, 1:26 beginning with the male. 1:27 Let's zoom into this section here. So here is the male sex organ. The primary 1:33 sex organ gland 1:36 is known as the testes. The testes is very important for the male reproductive 1:41 system because of two 1:42 things. First, it makes these gametes known as sperm for male, and it also 1:48 secretes certain hormones, 1:50 mainly testosterone, which causes the male characteristics to emerge. These 1:55 other male reproductive 1:57 structures found in this diagram, essentially their role is to help the sperm, 2:01 either for nourishment 2:03 or for the ejaculation process. So the sperm will then go through the epidermis 2:08 first, 2:08 from the testes, where it matures, fully matures, and during ejaculation, it 2:13 will pass through the 2:14 ductus deferens, pass through the urinary bladder, out through the ejaculatory 2:19 duct here, 2:20 where it will mix with semen from the seminal vesicles, and then all this sperm 2:26 and semen will 2:27 pass through the prostate gland, and the bulborethole gland, and then out 2:32 through the penis. 2:34 Of course, the process of sperm passing through all these structures here are a 2:40 bit more complex, 2:42 and we'll look into later on. But essentially, all these other structures help 2:46 in nourishing the sperm, 2:48 giving it all the things it needs in order to go into the vagina safely, you 2:55 can say. 2:56 And so now let's look at the female reproductive system. Now the primary female 3:03 reproductive organ 3:04 is the ovary, and the ovary, similar like testes, has two main roles. Firstly, 3:11 it produces the gamete, 3:13 known as the ovary, egg, and this occurs every month. And the ovaries also 3:19 secretes hormones, 3:20 two main ones, estrogen and progesterone, and these are hormones help in 3:25 enhancing or actually 3:27 providing the female characteristics such as breasts, which are accessory 3:31 organs, 3:31 also causes females to have curved hips, and testosterone for males, as I 3:37 mentioned earlier, 3:38 causes male characteristics such as male having broad shoulders and being very 3:43 hairy. 3:43 Now going back to the female reproductive system, before I continue, it is 3:47 important to note, 3:48 if you can see the difference between the male reproductive organs and the 3:51 female reproductive 3:52 organs, you can see slight similarity in that there are two ovaries and there's 3:57 two testes, 3:57 for example, and one uterus and one penis. And this is because both male and 4:03 female start 4:04 the same, before roughly six weeks. And it is after six weeks that six 4:09 determination occurs, 4:10 depending on if the sperm and the ovum combine to form an XX or an XY. 4:16 If it's an XX, this will produce a female. If it's an XY, it'll produce a male 4:24 baby. 4:24 Now going back to the female reproductive organs here, it is important to note 4:29 that the 4:30 other female reproductive organs, besides the ovaries, their function is 4:34 essentially to assist 4:35 the gamete, the female gamete, the ovum, to travel through and implant in the 4:42 uterus. 4:43 So these other organs, associated organs, of the female reproductive system are 4:49 the fimbriae, 4:50 the fallopian tubules, the uterus, the myometrium, the endometrium where 4:56 implantation occurs, 4:58 the cervix and, lastly, the vagina. Now, how does fertilization occur, 5:06 the combination of the sperm and the ovum? Now let's look at a sexual 5:11 intercourse between 5:12 male and female for this. And this, we are looking at a side view, a cross- 5:17 sectional view. 5:18 And so here we have a fully erected penis. A fully erected penis is filled with 5:24 blood. 5:25 And here are the other male reproductive organs. And these are the testes. 5:31 Remember that the urinary 5:33 bladder here is not actually part of the male reproductive system, it's part of 5:37 the urinary system. 5:38 Anyways, the other male reproductive organs structures are the epidermis, the 5:44 vas deferens, 5:45 the seminal vesicles, the ones that secrete semen, and then the prostate gland. 5:50 And then we have 5:53 the penis, the remaining penis. And the penis during sexual intercourse will go 5:58 into the vagina, 5:59 where this is a side view of a female reproductive system. So here we have the 6:05 vagina, 6:05 which grips onto the penis. And then here is the cervix. And here is the uterus 6:10 . And then the other 6:12 associated organs of, or the other organs of the female reproductive system are 6:17 the main one, 6:18 the ovary. And then we have the fallopian tubules here. Now it is important to 6:23 know that sperm is 6:25 made by the testes, but the sperm is stored by the epidermis. And that the ov 6:33 ovary produces the 6:34 ovah, which actually begins traveling through the fallopian tubules. It hasn't 6:39 implanted yet. 6:40 Now during sexual intercourse, when the penis is about to ejaculate, the sperm, 6:45 which is stored 6:46 in the epidermis, will then move out. This person is known as ejaculation. And 6:52 each ejaculation 6:54 will release about 20 million to 100 million sperm. And so the sperm will 7:00 travel through 7:01 the vas deferens, mix up with the semen from the seminal vesicles, and then go 7:06 out of the 7:07 erected penis into the vagina. And all the sperm will then travel through the 7:14 female reproductive 7:14 system and trying to find the ovum. And only one sperm will fuse with the ovum, 7:23 which is the process 7:25 known as fertilization. And so as you can imagine, if there are millions and 7:30 millions of sperm, 7:31 there is competition. And there's only one winner. And so this one winner will 7:35 essentially create 7:37 the baby, you can say, together with the ovum. So the fusion of sperm and ovum 7:41 is known as 7:42 fertilization, which will then produce a zygote. And then through cell division 7:49 , 7:49 a more and more cell division will create an embryo, which will later form a 7:53 baby or fetus. 7:54 Now let's have a look at the fertilization process and how embryo is slowly 8:01 developed 8:02 in a bit more detail. So here we have the female reproductive organs again. Now 8:07 the ovary produces 8:09 an ovum and then releases it from the ovary, a process called ovulation. Note 8:13 that the ovum has 8:15 two fates. It can either just implant in the uterus and will not fertilize with 8:23 the sperm, 8:24 and which will then cause period for women or not also known as menstrual cycle 8:28 . And therefore 8:30 ovulation actually occurs every month. However, if fertilization would occur, 8:38 firstly, we have to see what happens during sexual intercourse. This sperm will 8:43 thoroughly penetrate the vagina, releasing semen after ejaculation. And a lot 8:50 of semen will be 8:51 released, about 20 million, up to 120 million sperm. And all these sperm will 8:58 try to compete 8:58 with each other to go to the ovum within the fluopian tubules. And only one 9:03 sperm will fuse 9:05 with the ovum here. And this process of sperm and ovum fusing together is known 9:09 as fertilization. 9:11 And actually, the ovum itself is actually well protected, and so competition is 9:16 much more 9:17 challenging. After a few hours, this zygote will turn into a morilla, a cluster 9:29 of cells, 9:29 a bowl of cluster of cells known as a morilla. And then again, after some time, 9:34 it will form 9:35 into a blastocyst, which consists of two main cells, the outer trophoblast, and 9:41 the inner cells 9:42 on the inside called the inner cell mass. And then the blastocyst, blastocyt, 9:50 will then travel 9:51 through the uterus and implant on the endometrium. The endometrium contains 9:59 good, very good blood 10:00 supply. And so this is good for embryonic development. And so the trophoblast 10:05 will defuses with the endometrium cells, bringing in the inner cell mass with 10:12 it. And it is this 10:13 inner cell mass that actually develops into an embryo, which will then become a 10:17 baby. And so after 10:18 weeks, this inner cell mass will develop slowly into a bigger and bigger embryo 10:23 . So for example, 10:24 at six weeks, we will have already a good size embryo. And it's actually during 10:30 the six weeks, 10:31 where gender change is important, because this is where six differentiation 10:36 occurs, 10:36 depending on if the embryo has an X and an X-6 chromosome or an X and a Y-6 10:42 chromosome. And then 10:44 again, essentially, the pregnant female's belly will become larger. As the 10:52 fetus within her grows 10:55 and develops. And so at nine months or a full trimester, the fetus is ready to 11:00 be released 11:01 out of the body. How does this happen? Well, as the fetus is going larger and 11:06 larger, 11:07 it will slowly push against the cervix and move. The fetus will start moving 11:12 and push against the 11:12 cervix. What this will cause is that it will send the cervix will then send 11:17 nerve impulses 11:19 into the brain. And this will then cause the brain to stimulate the pituitary 11:25 glands, 11:25 which are endocrine glands, to secrete a hormone known as oxytocin. And then 11:32 this oxytocin causes 11:34 uterine contraction, causes the uterus to contract thoroughly, pushing the 11:39 fetus out. And then 11:41 as the fetus is pushing into the cervix, again, this will again cause the 11:45 the pituitary gland to secrete more oxytocin. And the cycle just continues and 11:49 continues. 11:50 And this cycle is known as a positive feedback loop, because it is enhancing 11:57 the stimulation 11:57 of each other, you can say. And so at childbirth, through positive feedback, 12:02 the baby, the fetus, now a baby, is able to come out of the vagina. 12:10 Thank you for watching the human reproductive system overview. I hope you enjoy 12:15 that. 12:15 Please like, comment, share. Thank you.
