Class 12 NEET - Biology | One Shot | Human Reproduction | Xylem NEET Tamil

Brief Summary

Alright guys, this video is all about human reproduction, a super important chapter for your 12th exams. We're going to cover the male and female reproductive systems, how fertilization happens, pregnancy, childbirth (parturition), and lactation. Key takeaways include understanding the functions of different reproductive organs, the process of gametogenesis (sperm and egg formation), the menstrual cycle, and the importance of breastfeeding.

  • Male and female reproductive systems and their functions.
  • Gametogenesis (sperm and egg formation).
  • Menstrual cycle and hormonal control.
  • Fertilization, pregnancy, and embryonic development.
  • Parturition (childbirth) and lactation.

Introduction to Human Reproduction

So, we're diving into human reproduction, covering everything from the male and female reproductive systems to fertilization, pregnancy, childbirth, and lactation. The main topics include the male and female reproductive systems, fertilization and implantation, pregnancy and embryonic development, parturition (birth), and lactation.

Male Reproductive System

Let's start with the male reproductive system. It consists of the testes, epididymis, vas deferens, seminal vesicles, prostate gland, bulbourethral glands, and the penis. The testes are key for sperm production. The scrotum maintains the testes at a temperature 2 to 2.5 degrees lower than body temperature, which is important for sperm development. The penis becomes erect during sexual reproduction to inject sperm into the female body.

Testes and Sperm Production

The testes have compartments called testicular lobules, each containing seminiferous tubules where sperm are produced. Inside these tubules, you'll find spermatogonia (sperm mother cells) and Sertoli cells, which provide nutrition to the developing sperm. Leydig cells, located between the seminiferous tubules, produce testosterone, the male hormone. Sperm plus the secretions of glands equals semen.

Sperm Structure and Function

The penis is made of special tissue that helps in erection, which facilitates insemination. The secretion of the bulbourethral gland helps in lubrication of the penis.

Female Reproductive System

Moving on to the female reproductive system, it includes the ovaries, fallopian tubes, uterus, cervix, vagina, and external genitalia. The fallopian tubes have parts called the ampulla and isthmus, where fertilization happens. The uterus has three layers: the endometrium (inner layer that changes during the menstrual cycle), the myometrium (muscle layer for contractions), and the perimetrium (outer layer).

Ovaries and Mammary Glands

The opening of the vagina is often covered by a membrane called the hymen. The mammary glands contain mammary lobes with alveoli that secrete milk. Milk is released through lactiferous ducts.

Gametogenesis: Sperm Formation

Now, let's talk about gametogenesis, the formation of gametes (sperm and egg). In males, spermatogenesis starts at puberty. Spermatogonia undergo mitosis and then meiosis to form sperm. Primary spermatocytes undergo meiosis I to form secondary spermatocytes, which then undergo meiosis II to form spermatids. Spermatids transform into spermatozoa (sperm) through spermiogenesis.

Gametogenesis: Egg Formation

In females, oogenesis (egg formation) starts during embryonic development. Oogonia undergo mitosis and differentiate into primary oocytes, which get arrested at prophase I of meiosis I. At puberty, these primary oocytes resume meiosis. A primary follicle becomes a secondary follicle, then a tertiary follicle, and finally a Graafian follicle.

Oogenesis and Follicular Development

A female is born with 60,000 to 80,000 primary follicles. The tertiary follicle has a fluid-filled cavity called the antrum. The primary oocyte completes meiosis I to form a secondary oocyte and a first polar body. The Graafian follicle ruptures to release the secondary oocyte (ovulation).

Ovulation and Corpus Luteum

During ovulation, a secondary oocyte is released. The second meiotic division completes only when the sperm fertilizes the secondary oocyte. After releasing the egg, the Graafian follicle becomes the corpus luteum, which produces progesterone. If fertilization happens, the corpus luteum stays and produces progesterone for nine months. If not, it degenerates.

Menstrual Cycle

The menstrual cycle is a series of events that repeats every 28 days. It includes the menstrual phase (bleeding), the follicular phase (follicle development), ovulation (egg release on the 14th day), and the luteal phase (corpus luteum formation). FSH (follicle-stimulating hormone) helps in the conversion of primary follicles into Graafian follicles. Estrogen thickens the uterine lining.

Hormonal Control and Menopause

LH (luteinizing hormone) induces ovulation. If fertilization happens, the corpus luteum produces progesterone for nine months. Menopause, when the menstrual cycle stops, happens around 50 years of age.

Fertilization and Implantation

Fertilization is when the sperm fuses with the egg (secondary oocyte) to form a zygote. Only one sperm can fertilize an egg. The zygote undergoes cleavage (cell division) to form a blastocyst. The blastocyst implants into the uterine wall.

Sex Determination and Embryonic Development

Sex is determined by the sperm: an X chromosome results in a female, a Y chromosome in a male. The blastocyst has an outer layer (trophoblast) and an inner cell mass. The trophoblast attaches to the uterus wall, and the inner cell mass becomes the developing embryo.

Placenta and Hormones During Pregnancy

The placenta produces hormones like HCG (human chorionic gonadotropin), HPL (human placental lactogen), estrogen, and progesterone. These hormones maintain pregnancy and support fetal growth.

Embryonic Layers and Fetal Development

The inner cell mass differentiates into three layers: ectoderm, mesoderm, and endoderm, which give rise to all the tissues and organs. By the end of the first month, the heart is formed. By the second month, limbs and organs are formed. By the third month, all organ systems are developed.

Parturition and Lactation

Parturition (childbirth) is induced by oxytocin, which causes uterine contractions. Lactation is the production of milk by the mammary glands. Colostrum, the first milk, is rich in antibodies and provides immunity to the newborn. Breastfeeding is recommended for healthy infant growth.

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0:00 foreign

1:11 perfect so guys human reproduction class 12th what a mega important on a chapter yes perfect so first topics

2:29 he said yeah human sexual reproduction.com there is a male organism the female organism s for example human cell is sperm and female cell is over in the cell yeah

3:16 important when they reproductions foreign said yeah

4:44 fertilization and implantation peninsula fertilization pregnancy and embryonic development female pregnant lactation partition of birth of the baby and lactation foreign

6:44 yes male reproductive systems foreign

8:09 difficulties

8:58 penis and scrotum knowing about Allah it is test is here important in a test is

9:56 foreign

10:57 [Applause] foreign [Applause]

12:07 foreign

13:20 [Music] foreign as well as sperm foreign

14:33 foreign so on the liquid spermuses foreign

15:39 it will become erect at the time of sexual reproduction s to inject male sperm into the female body in one day

16:29 you know yes releases the sperm as well as the secretion of the glands into the urethra okay foreign enlarged at the Apex foreign

17:52 was difference difference foreign

18:46 Clan yes let's go forward foreign

19:34 keeps the temperature of the test is two to five degrees lower test is 2 to 2.5 degree Centigrade yes

20:28 foreign

21:15 goodbye testy kular lobules 250 compartments in each testes see there are 250 compartment 250 compartments each test is 250. sorry foreign coiled tube marinerary in the Murray

22:02 coiled sir yeah in the coil tubular testicularly in the tubular spare parts

22:53 there are seminiferous tubule inside the testicle abuse so it will be one two three in each lobule only in the moon testicular semiferous tubules one two three semifinals tubules are the seminiferous tubules it leads to something called as test is it it is

23:52 foreign in there

24:46 foreign

25:56 sperm spermatogonia foreign

26:48 it provides nutrition to sperm even when the sperm go in the nutrition provides test is testicular lobules and the compartments okay is the

27:40 foreign you know ladies in between the seminiferous tubules testicular lobular seminiferous

28:32 also called as interstitial cellular foreign

30:01 effective foreign

31:29 it is production of sperm sperm production or sperm formation can help under this provide nutrition to the sperm otherwise the nutrient provides interstitial cell also called as latex synthesize testicular hormone that is testosterone or Androgen but Androgen particular they are collectively male hormones foreign

33:20 they are taking care of it okay so like that you can say in the I am giving you this View you are looking from here

34:10 it's like that in the diagram of the importance sperm

35:12 plus secretion of glands is equal to siemen glands or the secretion secretion of the gland together they form the semen okay perfect is a common passage for semen and urine so yeah penis is made up of special tissue which helps in erection to facilitate inseminations it will become erected so basically it's like this so it will

35:58 become erected at the time of sexual intercourse the female reproductive system

37:12 opening of perfect secretion of the gland is called as seminal Plasma in the moon or a section in the moon gland glances

38:22 so to provide it with nutrition secretion of bulb urethral gland helps in lubrication of penis in the gland foreign in the spermer release

40:13 so diagram Burger over here is fallopian tube per egg for my Indian egg for my Inca Pogo in the fallopian tubes

41:09 ampulla and isthmus is fertilization

42:03 and yeah Fusion of male and female gametes structures

43:03 vagina cervix canal yeah the baby which is Born the uterus movies

43:59 every month the endometrium layer is formed and it is destroyed Destroyer yes muscle of the uterus in the myometrium the contractions it will create contraction which will push the baby outermost layer perimetrium is endometrium myometrium perimetrium endometrium

45:16 endometrium myometrium perimetrium cervix and vagina together form the birth canal external genitalia muscle exhibit strong muscular contraction during childbirth strong muscular contraction endometrium inner glandular layer undergoes cyclical changes during menstrual cycle layer soon

46:32 in the region it's a membrane covering the vagina hair follicles a cushion of fatty tissue covered by

47:19 skin and hair pubic hair labia majora are fleshy fold of tissue which extends down the mons pubis surround the vaginal opening is paired full tissue under labia majora Libya fold tissues circuit

48:07 it will have Sensations Syria it's a tiny finger-like structure which lies at the upper Junction of two labia minor above the urethral opening in the labia minor clubs versus said yeah the opening of vagina is often covered by a membrane called as hymen is considered as sign of virginity which is

48:53 wrong virginity or sexual experience the thus female has not had sexual experience gets broken down because so presence or absence of a hymen is not a sign of virginity is often broken down during first intercourse first time the penis is so uh

49:39 so if hymen is the female has had sexual experience for example horse riding bicycle so presence or absence of hymen does not suggest virginity or anything okay foreign

50:34 each divides into 15 to 20 mm glandular tissue Circle and fatty tissue group number glandular tissue plus it is divided 15 to 20 mammary lobes each consisting of group of alveoliable foreign

53:16 at the clock flow memories okay yes foreign

56:38 yeah foreign

57:54 and ovary in female test is yes because there's one male there's one female guitars yes it should also have two n number of chromosomes so far by the process of meiosis so n number of chromosomes from father n

58:42 number of chromosomes from mother random saying the two n number of chromosomes foreign

1:00:43 spermatocyte primaries they get differentiated primary spermatocyte primaries meiosis one start ago meiosis one meiosis

1:01:36 spermatocyte Syria second now is so yeah this is meiosis one is happens in two stages four cells are formed on a chromosome number one the second is

1:02:22 it will undergo meiosis spermatted said yeah so foreign hmm spermio Genesis

1:03:12 meta zoa England is the second is foreign

1:04:12 the chromosome number will be n ope what is the chromosome number in secondary spermatocyte and chromosome number in primary is spermatocyte two and others yes putting it up yes process of transformation of spermatted into sperm or into spermatozoa is called as yes permeal Genesis very very important spermatogonia mitosis and differentiation mitosis

1:05:06 foreign react

1:05:53 ants release of the sperm from the seminiferous tubule sperm younger seminiferous tubules permeations

1:06:45 so excuse me sorry matters that is Syria

1:07:31 in the diagram important examples it is embedded into the yes it is embedded into the if you can

1:08:17 see certainly certainly the spermattedness is foreign foreign

1:09:12 and tail buddy either in the head region either but the middle piece is

1:10:21 foreign

1:12:36 foreign yeah hormone producers GnRH ypes or luteinizing hormone and FSH that is follicle stimulating hormone

1:13:21 hypothalamus or hormone produced when the information is tubules to release Androgen and the Androgen stimulates spermatogenesis foreign

1:14:08 releasing hormone pituitary in the hormone foreign which help in

1:14:54 spermatogenesis they help in maturation or helping no nursing or providing nutrition to the sperms in a way it is helping in spermatogenesis foreign

1:16:24 [Music] and a female leading a parting and a formation of egg embryonic stage layer starter difference when they are 12 to 15 years of age formation is initiated during embryonic development embryonic development up away the Star title are present in the each ovary at that time no more ugonia added after birth

1:17:28 foreign meiosis one enter Penny primary form panel embryonic stages it will start meiosis one and form primary oocyte and in the meiosis one

1:18:13 when the complete it gets stuck in prophase one is in meiosis there is there are four stages meiosis one meiosis one Anna phase one meta phase one Tila phase one is two so um it gets arrested so meiosis one is

1:19:03 which is stuck at prophase one of meiosis is called as foreign it gets surrounded by granulosa cells around

1:19:49 the cell primaries primary units primary follicles a female is born a female is born with you know 60 000 to 80 000 primary follicle

1:20:38 barring apart so primary follicularly Millions it will become primary use side and it will get surrounded by a layer of granosis and from primary follicles foreign

1:22:08 cell and form primary follicle and when female is born with a 60 000 to 80 000 primary follicles foreign follicle will mature into secondary follicle primary follicles it will get surrounded by more layer of granulosa cell secondary follicle

1:22:56 when the primary follicle gets surrounded by more any rendoon layer of granosis secondary follicles foreign

1:23:54 there is a fluid filled cavity and terminal and terminal fluid filled cavity in another tertiary follicle or fluid-filled cavity is foreign gets completed meios has been completed

1:24:39 but a primary uses cell primary follicles foreign said yeah

1:25:25 primary follicles it will be n area seconds

1:26:14 in the meiosis one is one day it will act as an egg foreign follicle

1:27:02 secondary follicle when the tertiary follicle tertiary follicle when the graphene follicle are Syria primary follicles ight plus first polar body

1:27:49 enough foreign okay yes a female has primary follicle and after puberty every month one primary follicle will undergo this journey

1:28:35 in the graphene follicles follicle gets converted into graphene follicle then egg is released ovulation happens in this thing is it will get converted into graphene follicles okay follicle is

1:29:23 foreign gets converted into graphene follicle

1:30:09 about tertiary follicles foreign the cavity is very big over here okay and it also has a Zona pellucida layer

1:31:06 is foreign oxide so after a point

1:31:53 after a point the graphene follicle ruptures and releases the secondary oocyte it is sir secondary use site when the first amniosis second meiosis younger purchaser second meiosis foreign

1:32:52 comes when the sperm comes and fertilizes the secondary oocyte or the eggless second meiotic division on the complete interesting ah irapa so egg is released as what egg is released as secondary oocyte in the secondary miotic division the sperm and the fertilizer in the secondary colors because

1:33:42 foreign at the time of fertilization during ovulation what is present inside the egg a secondary oocyte is present inside the egg what is the chromosome number n the chromosome number is okay so meiosis [Music] the ugonia undergoes meiosis still

1:34:27 prophase one so yeah primaries primary follicle foreign

1:35:23 the first meiotic division gets completed and primary oocyte one this secondary oocyte and first polar body are the chromosome primaries embryonic stage foreign

1:36:42 of the egg release of OVA or the Egg so what is the cell inside the egg secondary oocyte cell is present inside the egg or the over second meiotic division in whose secondary oocyte yep when the sperm fertilizes secondary oocyte at that time the second meiotic division gets completed second beautification the second polar body when the degenerator foreign

1:38:03 after releasing the head the graphene follicle gets converted into the corpus luteum yeah it produces hormone progesterone purita in the graphene follicle rupture graphene Williams luteum produces progesterone and the progesterone important part yeah

1:38:49 important yeah so graft and follicles yeah yes in the egg release I.E and the Egg one the spermala fertilized in the corpus luteum will stay it will stay and keep producing progesterone and the Fertilization in the corpus

1:39:36 luteum on the degenerate Arrow into Corpus albigans and then get degenerated and progesterone Productions foreign

1:41:13 fertilization happens the corpus luteum will stay for nine months and we'll keep on producing progesterone so that the baby can be nourished in the fertilization within 10 days it will get degenerated position Productions on the endometrium when the ordinance said yeah in the cross section perfect yes very good very good perfect so yeah so Genesis is the part of the

1:42:00 process of formation of egg so yeah it starts in the embryonic stage embryonic stages it stops at prophase one so primary website is formed it is having how many chromosomes 11 the rent two and number of chromosomes is female is born with sixty thousand to eight thousand on the primary foreign

1:42:59 then the secondary follicle foreign follicle which has secondary oocyte will

1:43:46 get converted into graphene follicle in the graphene follicles the second meiotic division is pending and it will get completed only when the sperm is fertilizing the secondary oocyte sperm on the touch it will become egg nucleus and second polar body in the second polar body when they degenerate okay so yes again one more time let us revise

1:44:33 it undergoes mitosis and differentiation it forms primary oocyte primary oocyte first meiotic division completed prior to visit from secondary use side second you said fetal life fetal life embryonic stages and first polar body is from it get degenerated and this forms ovum and the second polar body when does this happen this happens secondary performance when the sperm is fertilizing it foreign

1:45:25 taking place in the female reproductive systems 28 days in a bleeding foreign

1:46:38 menstrual phase appearing Syria so mother Moon Family Practice systems layer okay 14th day is important yes are important

1:47:27 ovulation ovulations [Applause] graphy and follicle so the graphene follicles so 14th day is

1:48:13 foreign Supreme Corpus

1:49:21 Christ foreign menstrual phase zero to five days second

1:50:09 phases follicular phase third phase is um hormones

1:51:05 pituitary hormone ovary and hormone hormone in the render hormone pituitary hormone foreign help in conversion of primary follicle into graphene follicle in The transformational Help primary follicular

1:51:51 graphene follicular follicle stimulating hormones stimulate hormone stimulate hormone follicular process uh you trust lining a thick Pannu uterus lining when the thick thick paneer in the estrogen parting you know in the Easter produce

1:53:08 foreign on the 14th day ovulations

1:54:00 foreign [Music] foreign

1:55:12 foreign calendar foreign

1:56:15 I hope you're understanding little analogy so in case fertilization happens and the zygote is formed because it will not degenerate it will keep staying and produce progesterone for nine months foreign

2:00:02 mother's body foreign

2:01:08 is ready cycle it's a cycle of events starting from one menstruation till the next one Syria menstrual cycle in a cycle of events

2:01:59 beginning of menstruation first periods the primary follicle when the female guitar foreign

2:04:05 menstrual cycle sees this around 50 years of age that is termed as menopause menopause foreign the penis penis is

2:05:06 the penis is inserted into the vagina erected Prince into the vagina ingra sperm release foreign

2:06:14 fuses with the egg or over to form the zygote for my rooms foreign using it foreign

2:07:38 you know first menstrual cycle is happening on 14 14th so 12 7 again 28 days plus 14 that is 24th egg release ago so if they involve in sexual intercourse around four you know uh 24 of the month date of the month chance of getting pregnant so and Innovations you should avoid sexual intercourse around the 14th day Syria 14th day 14 there are exactly 14

2:08:24 around 14th day you know complicated 17 days foreign

2:10:33 so how how to ensure only one sperm fertilizes an egg because once the sperm fertilizes the egg there are changes taking place in the membrane of the egg which allow which stops entry of further sperms yes guys yes only one's perm is fertilizing the egg and as soon as the sperm touches the second meiotic division one the complete Target nucleus egg nucleus plus second polar body form argument and the second pole are body in a particular waste iron and this egg nucleus combines with the sperm nucleus to form the zygote so I guess

2:11:18 foreign so yeah

2:12:30 I don't know why chromosome containing sperm when they fertilizer you will get a male breeda X chromosome fertilizers but why chromosome containing um father the sperm of the father because the mothers have same rights

2:13:39 compared to boys initial

2:14:25 cell division in zygote foreign

2:15:36 the cells of the initial foreign

2:16:52 it will get divided into trophoblast even the render part of divided in the cavity and inner cell Mass attach

2:17:54 to uterus wall if the trophy plastic light on the uterus wallet Inner Cell Mars this it becomes into the developing embryo even the embryo converts in there foreign

2:18:39 attaches to the wall of the uterus Inner Cell mass that converts into the developing embryo implantation implantation the embedding of the trophoblast and the trophoblast when the number uterus followers foreign

2:22:32 hpl human placental lactogen estrogen progesterone in the hormones which hormones are produced by the placenta human chorionic gonadotrophone foreign

2:23:19 human placental lactogen Syria estrogen is also produced by the present or Pleasant relaxation HCG hpl and relaxing are produced only during pregnancy important in the HCG hpl performance cortisol prolactin thyroxine levels increase which are fetal necessary for fetal growth metabolic changes in mother and the maintenance of pregnancy in the

2:24:04 hormones cortisol Syria prolactin thyroxine in the hormones because maintenance in the slide the director foreign

2:24:53 okay perfect immediately after implantation the Inner Cell Mass differentiates into three layer these three layer give rise to all the tissue

2:25:46 blasters foreign and Outsiders ectoderm ape

2:26:41 innermost layer is foreign so era

2:27:33 is starting to beginning to form the embryo so yeah so this is Syria perfect Siri Inner Cell Mass contains certain cells called as stem cells which have potency to give rise to all the tissues and

2:28:20 organs but in the Inner Cell Mass yes because it has potency to give rise to all the tissues and organs

2:29:08 by the end of the first month heart is formed fertilizations second month that is eight weeks Limbs and organs are formed four weeks third month all organ systems are developed third monthly organ system Developers interesting then second trimester that is four to six months fetal movements begin

2:29:55 appearance of hair by the end of six months or 24 weeks fine hair arrives all over the body ice and separate eyelashes separated first of all by the end of nine months fully developed fetus is formed nine months important first monthly second month or against foreign okay very good

2:31:05 yes induces maternal foreign

2:32:04 induces further release of oxytocin causes stronger uterine contraction and delivery of the birth happens delivery of the baby happens steady last topic partnering in Upper lactation lactation antibodies

2:33:07 the mammary gland of the female undergoes differentiation during pregnancy and starts producing milk towards the end of pregnancy by the process called as lactation so they end on the lactation initial few days of lactation is called as colostrum important the first milk blessed in the first to develop resistance to a newborn baby breastfeeding during initial periods of infant growth is recommended by doctors for bringing up healthy baby another breastfeeding month important

2:33:53 so yeah yes come on claps well now we're gonna create a track great job a great job Concepts make notes from this so yeah in the in the video and then the path notes in the

2:34:40 nodes if you want the PPT of this session in a comment boxes so thank you thank you for attending the session um

2:35:43 leave hard putting knowledge

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