1. Human Sexual Reproductive System

2. By the end of the lesson, we should be able to answer: What is the importance of the human sexual reproductive system? How do parts of the different human reproductive systems work together to create new life? How can the introduction of contraceptives affect the ability to reproduce?

3. Human Sexual Reproductive System Why is reproduction important? What is sexual reproduction? What are the parts that make up the male and female reproductive systems? What do the male and the female reproductive cells look like?

4. Human Sexual Reproduction System One thing that you would have noticed is that children look quite similar to their parents. They might not look 100% exactly like either of their parent, but they definitely have gotten some features from both of their parents! So, why do they look like their parents?

5. Human Sexual Reproductive System Humans, like all other organisms, must produce new organisms like themselves for their kind to survive. The process by which humans produce new organisms like themselves is called reproduction.

6. Human Sexual Reproductive System: Why is reproduction important? Reproduction ensures the transfer of genetic information from one generation to another. (Heredity) It ensures the continuity of a species. Humans reproduce through sexual reproduction, which involves a male and a female adult. For sexual reproduction to occur, both the male and female reproductive system must be present.

7. kidney urinary bladder urethra penis Sperm duct The sperm duct is a muscular tube that carries sperms from the testis to the urethra. Sperm duct The sperm duct is a muscular tube that carries sperms from the testis to the urethra. Male sex glands The male sex glands secrete a fluid containing nutrients and enzymes. The nutrients and enzymes provide the sperms with the energy to move. The mixture of sperm with this fluid is known as semen. Male sex glands The male sex glands secrete a fluid containing nutrients and enzymes. The nutrients and enzymes provide the sperms with the energy to move. The mixture of sperm with this fluid is known as semen. Penis The penis is the male reproductive organ which becomes erect when sexually excited. Sperms are ejaculated through the penis during sexual intercourse. Penis The penis is the male reproductive organ which becomes erect when sexually excited. Sperms are ejaculated through the penis during sexual intercourse. Male reproductive system

8. kidney urinary bladder urethra penis Urethra The urethra is a tube which leads to the outside of the body through the penis. During sexual intercourse, sperms pass from the testes, into the sperm ducts and then into the urethra. The sperms pass to the outside of the body through the urethra. Urethra The urethra is a tube which leads to the outside of the body through the penis. During sexual intercourse, sperms pass from the testes, into the sperm ducts and then into the urethra. The sperms pass to the outside of the body through the urethra. Testis (plural: testes) The testis produces sperms and male sex hormones. Testis (plural: testes) The testis produces sperms and male sex hormones. Scrotum Each testis is found in the scrotum. Scrotum Each testis is found in the scrotum.

9. The human sperm is the male reproductive cell. The sperm has a long tail. The movement of the tail helps the sperm to swim towards the egg. The sperm has a head containing a nucleus. This nucleus contains genes that would be passed on to the new individual during fertilisation. Sperms are produced continuously after puberty. Sperm duct Penis Urethra Testis (plural: testes) Scrotum Sperm

10. kidney uterine lining urinary bladder Fallopian tube (or oviduct) The oviduct is a muscular tube connecting the ovary to the uterus. The wall of the oviduct contracts to push the egg along the oviduct towards the uterus. Fallopian tube (or oviduct) The oviduct is a muscular tube connecting the ovary to the uterus. The wall of the oviduct contracts to push the egg along the oviduct towards the uterus. Ovary The ovary produces eggs and female sex hormones. The ovaries take turns to produce an egg every month. Ovary The ovary produces eggs and female sex hormones. The ovaries take turns to produce an egg every month. Uterus (or womb) The uterus is a pear-shaped organ with thick muscular walls. The inner surface of the uterus is covered with a layer called the uterine lining. Uterus (or womb) The uterus is a pear-shaped organ with thick muscular walls. The inner surface of the uterus is covered with a layer called the uterine lining. Female reproductive system

11. kidney uterine lining urinary bladder Cervix The cervix is a ring of muscle at the lower end of the uterus. Cervix The cervix is a ring of muscle at the lower end of the uterus. Vagina (or birth canal) The vagina is a muscular tube. It joins the cervix to the outside of the body. Vagina (or birth canal) The vagina is a muscular tube. It joins the cervix to the outside of the body.

12. Egg The human egg (or ovum) is the female reproductive cell. They are produced by the ovaries. The ova starts to mature one at a time, starting from puberty. These ova will exist in a woman’s body from birth. Ova (plural) Ovum (singular) Egg The human egg (or ovum) is the female reproductive cell. They are produced by the ovaries. The ova starts to mature one at a time, starting from puberty. These ova will exist in a woman’s body from birth. Ova (plural) Ovum (singular) The egg contains a nucleus. (It is a cell – what else does it contain?) Ovary Uterus (or womb) Cervix Vagina

13. Sexual Reproduction How does human sexual reproduction happen? What occurs when a human is sexually matured (Puberty)?

14. Sexual Reproduction Sexual reproduction involves fertilisation. Fertilisation is the fusion of the male reproductive cell (sperm) and the female reproductive cell (ovum). Prior to fertilisation, sexual intercourse must occur.

15. For a woman to get pregnant, she must first have sexual intercourse with a male adult. 1. During sexual intercourse, the erect penis is inserted into the vagina. 2. The penis ejaculates semen (containing sperms) into the upper end of the vagina. The sperms will then swim into the uterus. Sexual Intercourse

16. When a woman gets pregnant, a new individual is formed in her womb. Prior to this, fertilisation must occur. 1. Sperms deposited in the vagina during sexual intercourse travel up the uterus through the oviduct to the egg. uterus oviduct ovary egg vagina sperm Fertilisation

17. 2. If an egg is present in an oviduct, fertilisation may take place. 3. The fertilised egg divides repeatedly to form the embryo. 4. The embryo moves into the uterus and is implanted on the uterine lining. The woman is now pregnant. uterus ovary oviduct vagina embryo

18. Pregnancy lasts about nine months in humans. 1. During pregnancy, the embryo develops into a foetus or unborn baby. 2. At the end of the pregnancy, the muscles of the uterus contract to push out the fully formed baby. The cervix enlarges to allow the baby to pass through. This process is known as birth. Pregnancy

19. Heredity (What is the definition?) How many of us here actually resemble our parents? You would notice that your siblings resemble your parents too! A baby will grow up to look like his parents because the sperm and egg carry information that determines the baby’s look. The nuclei of the sperm and egg contain genes. Genes contain instructions that determine the basic characteristics of a person. Genes are passed on to the new individual when the nucleus of the sperm fuses with the nucleus of the egg during fertilisation to form a fertilised egg.

20. The sperm carries genes from the father. The egg carries genes from the mother. The fertilised egg develops into an embryo. During fertilisation, genes are passed from each parent to the child. The sperm and egg fuse to form a fertilised egg. The baby that develops will inherit some characteristics from each parent.

21. So, what have we learnt so far?

22. Puberty Between the adolescent ages of 10 to 14, the human body starts to stimulate the production of certain sex hormones. It also produces a higher amount of growth hormone that leads to growth spurts. Sex hormones cause changes to the body and bodily functions.

23. Pubert y This period of bodily changes is called puberty. Puberty is the period when an adolescent becomes capable of reproducing. The adolescent also experiences rapid growth and development during this period. The person becomes physically mature. Girls experience puberty earlier than boys.

24. Facial hair starts to grow. Voice-box enlarges and voice deepens. Hair starts to grow in the armpits. The penis and testes increase in size. Production of sperms begins and ejaculation occurs. What are the changes to male and female bodies during puberty? Breasts and uterus enlarge and hips broaden. Hair starts to grow in the pubic region. A monthly cycle involving menstruation and ovulation begins. This cycle is known as the menstrual cycle.

25. Puberty We become sexually mature during puberty and our body secretes hormones that attract us to the opposite sex. We will also be able to reproduce by sexual reproduction. During puberty, sex and growth hormones cause changes to other body systems such as the skeletal and muscular systems. Boys will have heavier bones and an increase in muscle growth at the end of puberty. Girls will experience an increase in the amount of fat tissues at the breasts, hips and pubic region at the end of puberty.

26. Menstruation When a female reaches puberty, she will start to menstruate. Menstruation marks the beginning of the menstrual cycle in a woman. Menstruation is the discharge of the uterus tissues when an egg remains unfertilised.

27. Stages in the menstrual cycle - A typical menstrual cycle lasts 28 days Menstruation thin uterine lining is repaired Ovulation Fertile period uterine lining becomes thick uterine lining remains thick menstrual discharge Fertile period A mature egg is released into the fallopian tube. Sexual intercourse around the ovulation period is likely to result in pregnancy. Ovulation will most probably occur one of the days within this period. Fertile period A mature egg is released into the fallopian tube. Sexual intercourse around the ovulation period is likely to result in pregnancy. Ovulation will most probably occur one of the days within this period. Repair and growth of the uterine lining The uterine lining grows thicker. The lining becomes very rich in blood capillaries. Repair and growth of the uterine lining The uterine lining grows thicker. The lining becomes very rich in blood capillaries. Further thickening of the uterine lining The uterine lining remains thick to supply the embryo with nutrients and oxygen for growth. Further thickening of the uterine lining The uterine lining remains thick to supply the embryo with nutrients and oxygen for growth. Menstruation If a sperm does not fuse with an egg during the fertile period, the uterine lining breaks down again and menstruation begins. Menstruation If a sperm does not fuse with an egg during the fertile period, the uterine lining breaks down again and menstruation begins. Menstruation The first day of the menstrual cycle starts with the menstrual flow. Menstrual flow is the shedding of the unfertilised egg, uterine lining and blood. Menstruation The first day of the menstrual cycle starts with the menstrual flow. Menstrual flow is the shedding of the unfertilised egg, uterine lining and blood.

28. Pre-marital Sex and Abortion Pre-marital sex is the act of having sexual intercourse before a couple is married. Pre-marital sex often creates serious problems. Such problems include: Sexually transmitted infections Disrupts functionality of reproductive organs May cause difficulty for couple trying to start a family Unwanted pregnancy Not emotionally/financially prepared Social stigma May lead to abortion

29. Abortion Abortion is the termination of a pregnancy. Consequences resulting from abortion: Emotional problems such as depression Health complications Disruption of functions of sexual reproductive system Even more difficult to get pregnant/ Unable to get pregnant

30. What are some reasons for having abortions? Permanent harm to the mother if pregnancy continues. Child may be born with a physical/mental disability. Unwanted pregnancy resulted from rape. Life of mother or/and fetus is/are in danger. The mother is physically/mentally incapable of caring for the child. Family is not financially ready to support the child.

31. Then again, we shouldn’t reach the stage where we even consider abortion.

32. Birth Control Methods How do temporary and permanent methods of birth control affect the reproductive systems to prevent contraception? What are some of the sexually transmitted infections? How can we prevent the spread of sexually transmitted infections?

33. When a country is overpopulated, it may have problems producing enough food and homes for its people. One of the reasons of overpopulation is the lack of birth control. Overpopulated countries have tried to control birth rates by educating their people on birth control and making it more accessible to their people.

34. Birth Control Methods Birth control methods are used to prevent pregnancies. Work by preventing ovulation, fertilisation or implantation of embryo. Method used may be natural, chemical, mechanical or surgical. Can be temporary or permanent.

35. Temporary birth control methods Temporary birth control methods allow a couple to have children when the couple stop using the methods. They include: Not having sexual intercourse at all (abstinence) Withdrawal of the penis just before ejaculation The rhythm method Use of chemicals such as spermicides, contraceptive pills Use of mechanical devices such as condoms, diaphragms and intra-uterine devices

36. Temporary birth control methods Rhythm method Couples do not have sexual intercourse during the fertile period of the woman’s menstrual cycle. Sexual intercourse during fertile/unsafe period may lead to pregnancy Presence of mature egg in fallopian tube/oviduct

37. Temporary birth control methods Spermicide Spermicide is a chemical that kills/blocks sperms from entering uterus No fertilisation Inserted into the vagina in the form of gels, aerosol foams and foaming tablets uterusspermicide

38. Temporary birth control methods Diaphragm Dome-shaped rubber cap with elastic rim Inserted into vagina and placed over the cervix Impermeable hence prevents sperms from entering uterus No fertilisation uterus vagina diaphragm

39. Temporary birth control methods Condom Thin rubber tube Covers the erect penis before sexual intercourse Impermeable to sperms, sperms cannot enter uterus No fertilisation condom penis

40. Impermeable to bacteria and virus Protects the user from sexually transmitted infections (STIs) Temporary birth control methods Condom

41. Temporary birth control methods Intra-uterine device (IUD) IUD is a piece of plastic or metal inserted into the vagina by the doctor Disrupts function of uterus Prevents embryo from being implanted in the uterus Provides effective for a long period of time Fertilisation still takes place uterus IUD

42. Temporary birth control methods Contraceptive pills Contain certain female hormones which prevent ovulation Disrupt function of ovary Prevents mature egg from being released each month Possible side effects (eg dizziness or even more serious problems such as stroke)

43. Permanent birth control methods Requires surgery Irreversible Usually chosen by couples who are sure that they do not want anymore children Permanent methods include: Vasectomy Tubal ligation Permanently prevent fertilisation by disrupting functions of parts of reproductive system

44. Permanent birth control methods Vasectomy Tying and cutting part of the sperm ducts through surgery Disrupt function of sperm duct Sperms will not be ejaculated during sexual intercourse No fertilisation

45. Permanent birth control methods Tubal ligation Tying and cutting both oviducts during surgery Disrupt function of oviduct Prevents egg from meeting sperm No fertilisation

46. Temporary Birth Control Methods Permanent Birth Control Methods Prevents fertilisation Withdrawal of penis before ejaculation Rhythm method Spermicide Diaphragm Condom Prevents ovulation and implantation IUD Contraceptive pills Permanently prevents fertilisation Vasectomy Tubal Ligation Unreliable Methods Rhythm Method Withdrawal of penis before ejaculation

47. Sexually Transmitted Infections (STIs) Infection transmitted from one person to another through sexual intercourse. Contraceptives such as condoms can help protect against STIs. Having sexual intercourse with an infected person can cause you to contract STI. Common STIs include: Acquired Immune Deficiency Syndrome (AIDS) (Must know) Syphilis Gonorrhoea Just read for reference

48. Sexually Transmitted Infections (STIs) Infected people may not show obvious signs or symptoms. Unaware, they can spread the STI to their partners or unborn children. Multiple sex partners can increase the rate of infection. Annually, a few hundred teenagers in SG get infected with STI.

49. Sexually Transmitted Infections (STIs) During sexual intercourse, body fluids are exchanged in the reproductive systems. STI-causing bacteria or viruses are present in some of the body fluids of an infected person. Bacteria/Virus can enter the circulatory system of the sexual partner through their sexual reproductive system. STIs may also be spread through contaminated blood or childbirth.

50. Acquired Immune Deficiency Syndrome(AIDS) Caused by the Human Immunodeficiency Virus (HIV). HIV attacks the immune system: Person loses immunity Becomes vulnerable to common infections AIDS is the final stage of HIV – Immune system is severely damaged. Infected person suffers from severe weight loss, lung infections and brain infection.

51. Acquired Immune Deficiency Syndrome(AIDS) AIDS is a viral STI which is incurable and fatal.

52. Syphillis Infected people may suffer from blindness and inability to move some parts of their body. Left untreated, can lead to heart failure, insanity or death. One sign of syphilis is the presence of non-itchy skin rashes on the palm

53. Syphillis

54. Gonorrhoea Infected men and women may become unable to bear children if the disease spread to their reproductive system. Babies may be born blind if the bacteria enters the baby’s eyes during birth. Treatment for syphilis and gonorrhoea These bacterial STIs can be cured when treated with antibiotics.

55. Gonorrhoea Treatment for syphilis and gonorrhoea These bacterial STIs can be cured when treated with antibiotics.

56. Prevention and control Important to prevent STIs as some are incurable. Ways to control the spread and prevent infection: Avoid having multiple sex partners. Avoid sharing instruments that are likely to break the skin and become contaminated with blood (eg razors and needles), use disposable and sterile ones instead.

57. Prevention and control Ways to control the spread and prevent infection: Use condoms during sexual intercourse Not abusing drugs or sharing injection needles Ensure that donated blood is screened for HIV and safe for use

58. Map It Human Sexual Reproduction Premarital sex may be transmitted through sexual intercourse during occurs after Puberty is affected by Abortion Birth control methods occurs in Human reproductive system Sexually transmitted infections may lead to AIDS Syphilis Gonorrhoea such as Permanent Temporary consist of Vasectomy Tubal ligation (cont’d on the next slide)

59. Map It Abstinence Rhythm method Withdrawal of penis just before ejaculation Spermicides Diaphragms Condoms Intra-uterine devices Contraceptive pills Male in a Female develops into Embryo Menstrual cycle goes through Sperm duct Testes Scrotum Male sex gland Urethra Penis consists of parts produces Sperms produces Eggs fuse during carry Genes from parentsFertilisation that determine Hereditary characteristics forming Fertilised egg consists of parts Ovaries Fallopian tubes Uterus Cervix Vagina further develops into Foetus