Reproduction In Human And Issues On Sex


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Reproduction In Human And Issues On Sex

  1. 1. Sexual Reproduction in Animals
  2. 2. Types of Reproduction <ul><li>Asexual reproduction </li></ul><ul><li>Sexual Reproduction </li></ul>
  3. 3. Asexual Reproduction <ul><li>Single parent </li></ul><ul><li>New organism identical to parent </li></ul><ul><li>Occur in unicellular organims such as amoeba </li></ul>
  4. 4. Sexual reproduction <ul><li>Two parents </li></ul><ul><li>Male and female </li></ul><ul><li>Multicellular organism </li></ul><ul><li>Involved sex cells </li></ul><ul><li>Male sex cells – Testes/testis: sperm </li></ul><ul><li>Female sex cells – Ovary: Ova/ovum’ </li></ul><ul><li>Male and female sex cells join together to form a new organism different from the two parents </li></ul>
  5. 5. State some differences between sperm and ovum
  6. 6. The difference between sperm and ovum <ul><li>Sperm </li></ul><ul><ul><li>Released in millions </li></ul></ul><ul><ul><li>Able to move </li></ul></ul><ul><ul><li>Very small </li></ul></ul><ul><ul><li>Very little cytoplasm </li></ul></ul><ul><ul><li>Nucleus contain either X or Y chromosome </li></ul></ul><ul><li>Ovum </li></ul><ul><ul><li>Released one at a time </li></ul></ul><ul><ul><li>Unable to move on their own </li></ul></ul><ul><ul><li>Comparatively large </li></ul></ul><ul><ul><li>A lot of cytoplasm </li></ul></ul><ul><ul><li>Nucleus always contains an X chromosome </li></ul></ul>
  7. 7. Today’s Objectives <ul><li>At the end of this lesson you will be able to </li></ul><ul><ul><li>Identify on diagram of the male and female reproductive system </li></ul></ul><ul><ul><li>State the functions of: </li></ul></ul><ul><ul><ul><li>Testes </li></ul></ul></ul><ul><ul><ul><li>Scrotum </li></ul></ul></ul><ul><ul><ul><li>Sperm duct </li></ul></ul></ul><ul><ul><ul><li>Urethra </li></ul></ul></ul><ul><ul><ul><li>Penis </li></ul></ul></ul><ul><ul><ul><li>Sex glands </li></ul></ul></ul><ul><ul><ul><li>Ovaries </li></ul></ul></ul><ul><ul><ul><li>Oviducts </li></ul></ul></ul><ul><ul><ul><li>Uterus </li></ul></ul></ul><ul><ul><ul><li>Cervix </li></ul></ul></ul><ul><ul><ul><li>Vagina </li></ul></ul></ul>
  8. 8. A pair of testes and their tubes <ul><li>Two testes are oval and about 5 cm long </li></ul><ul><li>Contained in protective bag called scrotum </li></ul><ul><li>Produce sperms and male sex hormone, testosterone </li></ul><ul><li>Located outside abdominal cavity (lower temperature) </li></ul><ul><li>Lower temperature important for production of sperms </li></ul>
  9. 9. A pair of testes and their tubes <ul><li>Each testis contain great number of tiny coiled tubes </li></ul><ul><li>Tiny coiled tubes join together to form a few larger tubes called collecting tubes </li></ul><ul><li>From collecting tubes, sperm enter into a single coiled tube called storage duct (epididymis) </li></ul><ul><li>Epididymis stores sperms until they are released </li></ul>
  10. 10. A pair of testes and their tubes <ul><li>Each epididymis leads to sperm duct </li></ul><ul><li>Two sperm duct join up with the urethra just below the urinary bladder </li></ul><ul><li>Urethra passes through a muscular organ called penis </li></ul><ul><li>Urethra allows both urine and sperms to leave the body at different times </li></ul>
  11. 11. Gland <ul><li>Sex gland produce fluids in which the sperms swim </li></ul><ul><li>The mixture of sperms and fluid is called semen </li></ul>
  12. 12. The Penis <ul><li>Muscular organ carried both urine and semen from body to the outside </li></ul><ul><li>During sexual intercourse, the penis becomes stiff and erect due to blood flows </li></ul><ul><li>This causes the opening of bladder to be closed so that no urine can mix with semen in the urethra </li></ul><ul><li>Erect penis enter the vagina and release semen into it. </li></ul>
  13. 13. The Sperm <ul><li>Numerous sperms produced throughout the life of a mammal </li></ul><ul><li>Head with a diameter of 2.5 µm, contain large nucleus, little cytoplasm and acrosome (contain enzymes) </li></ul><ul><li>Middle piece contain mitochondria </li></ul><ul><li>Tail or flagellum for swimming </li></ul><ul><li>Nucleus can contain either X or Y chromosome </li></ul>
  14. 15. Female Reproductive System <ul><li>A pair of ovaries and a set of Fallopian tubes </li></ul><ul><li>The womb or uterus </li></ul><ul><li>The vagina </li></ul>
  15. 16. Pair of Ovaries and Fallopian tubes <ul><li>Two oval ovaries about 3 cm long </li></ul><ul><li>Attached to the back of body below the kidneys </li></ul><ul><li>Produce ova and female sex hormone </li></ul><ul><li>After leaving an ovary, the ovum passes into a tube called Fallopian tube or oviduct </li></ul><ul><li>Muscles found in the tube and on the inner sides of the walls are many tiny hairs </li></ul><ul><li>Fertilization takes place in Fallopian tubes </li></ul><ul><li>Lead into uterus or womb </li></ul>
  16. 17. The Uterus or Womb <ul><li>Like a pear which is upside down </li></ul><ul><li>Central cavity with thick walls </li></ul><ul><li>Made up special muscles that can stretch to many times their usual size </li></ul><ul><li>Uterus where a zygote grows and develops into feotus </li></ul><ul><li>Lower end of uterus is a ring of muscles called the cervix . </li></ul>
  17. 18. The Vagina <ul><li>Uterus leads into the vagina which is a tube with thinner walls </li></ul><ul><li>Vaginal opens to the outside through an opening called vulva. </li></ul>
  18. 19. The Ova <ul><li>Spherical with diameter of 120 µm </li></ul><ul><li>Large nucleus </li></ul><ul><li>Large cytoplasm </li></ul><ul><li>Surrounded with plasma membrane which is surrounded by an outer membrane </li></ul><ul><li>Nucleus can only contain X chromosome </li></ul>
  19. 20. Urinary bladder urethra vulva
  20. 21. Video clip Reproductive system
  21. 22. Sex Cells & Normal Body Cells <ul><li>What is the difference? </li></ul><ul><li>Normal human cell: 46 chromosomes/23 pairs chromosomes </li></ul><ul><li>Sex cells: Sperm/Ova – 23 chromosomes only </li></ul>
  22. 23. What is chromosome? <ul><li>Contain genetic information </li></ul><ul><li>Control how a person looks like </li></ul><ul><li>The information is inherited when sex cells fuse during fertilization and develop into offspring </li></ul>
  23. 24. Fertilization <ul><li>Semen contain millions of sperms </li></ul><ul><li>Sperms swim in the fluid semen up through the vagina, uterus and Fallopian tubes </li></ul><ul><li>If there is ovum in of the Fallopian tubes, one of the sperm may enter the ovum and fertilize it </li></ul><ul><li>Once sperm enters an extra covering will grow around the ovum to prevent other sperms from entering. </li></ul><ul><li>Remaining sperms will eventually die </li></ul>
  24. 32. Implantation <ul><li>Fertilized ovum moves towards uterus with the help of tiny hairs on the wall of Fallopian tube </li></ul><ul><li>As it moves, zygote divide many times </li></ul><ul><li>Tiny ball of cells called embryo </li></ul><ul><li>Enters the uterus embryo grows finger-like structures to attach itself to the lining of the uterus </li></ul><ul><li>IMPLANTATION of the embryo </li></ul>
  25. 33. Functions of Placenta <ul><li>Allows dissolved food substances & oxygen to diffuse from the mother’s blood into the embryo </li></ul><ul><li>Allow waste products to diffuse from embryo to mother’s bloodstream </li></ul><ul><li>Allows antibodies to diffuse from the mother’s blood into the embryo </li></ul><ul><li>Produces progesterone which maintains uterine lining healthy </li></ul>
  26. 34. Umbilical Cord <ul><li>Embryo attached to the placenta by a tube known as umbilical cord </li></ul><ul><li>Contains two umbilical arteries carry deoxygenated blood from foetus to placenta </li></ul><ul><li>One umbilical vein transport oxygenated blood and food substances from placenta to foetus </li></ul><ul><li>Foetus continues to grow until it is ready to be born </li></ul><ul><li>About nine months of development in uterus </li></ul><ul><li>Gestation is from conception to birth </li></ul>
  27. 35. What is the difference between the following terms? <ul><li>Zygote </li></ul><ul><li>Embryo </li></ul><ul><li>Foetus </li></ul>
  28. 36. Zygote <ul><li>Form when sperm and ovum fuse together </li></ul>
  29. 37. Embryo <ul><li>It is a general term to called the fertilized egg </li></ul><ul><li>From 2 cells onwards </li></ul>
  30. 38. Foetus <ul><li>Fully formed embryo </li></ul>
  31. 39. Video clip Fertilization and Birth In the womb
  32. 40. Today’s Objective <ul><li>At the end of this lesson you will be able to : </li></ul><ul><ul><li>Describe the menstrual cycle with reference to the alteration of menstruation and ovulation, </li></ul></ul><ul><ul><li>Describe the natural variations in its length, and the fertile and infertile phases of the cycle </li></ul></ul><ul><ul><li>State the effects, such as diet and emotional state, which affect the menstrual cycle </li></ul></ul>
  33. 41. Video clip Puberty
  34. 42. What is puberty? <ul><li>Stage of active growth in humans </li></ul><ul><li>Changes from child to adult </li></ul><ul><li>Reproductive system function properly </li></ul><ul><li>Age 11 for girls and 14 for boys </li></ul><ul><li>These changes is called secondary sex characteristics caused by sex hormones </li></ul><ul><li>In female will be oestrogen and progesterone </li></ul><ul><li>In male will be testosterone </li></ul>
  35. 43. Secondary Sexual Characteristics <ul><li>Boys </li></ul><ul><ul><li>Beard, hair in pubic area and armpit </li></ul></ul><ul><ul><li>Penis and testicles increase in size </li></ul></ul><ul><ul><li>Production of sperm starts </li></ul></ul><ul><ul><li>Larynx enlarges and voice deepens </li></ul></ul><ul><li>Girls </li></ul><ul><ul><li>Hair in pubic area and armpit </li></ul></ul><ul><ul><li>Breasts and uterus enlarge, hips broaden </li></ul></ul><ul><ul><li>Menstruation and ovulation start </li></ul></ul>
  36. 44. Video clip Menstrual Cycle
  37. 45. Menstrual Cycle <ul><li>For girl, the first sign of puberty is menstruation </li></ul><ul><li>Last about 5 days (depends on individual) </li></ul><ul><li>Average menstrual cycle for an adult woman is 28 days </li></ul><ul><li>May be affected by: </li></ul><ul><ul><li>Emotional disturbance </li></ul></ul><ul><ul><li>Stress </li></ul></ul><ul><ul><li>Mental fatigue </li></ul></ul><ul><ul><li>Illness </li></ul></ul><ul><ul><li>Unbalanced diet/malnutrition </li></ul></ul>
  38. 46. Menstrual Cycle <ul><li>Young follicles: primary follicles </li></ul><ul><li>Primary follicles will mature to form Graafian follicle which contain haploid egg </li></ul><ul><li>After ovulation follicle develops into corpus luteum to secrete progesterone </li></ul>
  39. 47. Stages of Menstrual Cycle <ul><li>Before ovulation </li></ul><ul><li>Ovulation </li></ul><ul><li>Menstruation </li></ul><ul><li>After Menstruation (before the next ovulation) </li></ul>
  40. 48. Before ovulation <ul><li>About 14 days before ovulation, ovaries release female sex hormones: follicle stimulating hormone (FSH) into bloodstream </li></ul><ul><li>FSH: </li></ul><ul><ul><li>Stimulates development of follicle </li></ul></ul><ul><ul><li>Stimulates follicles to secrete oestrogen </li></ul></ul><ul><li>Oestrogen: </li></ul><ul><ul><li>Causes lining of uterus wall to thicken </li></ul></ul>
  41. 49. Ovulation <ul><li>Luteinising hormone (LH) causes ovulation and formation of corpus luteum </li></ul><ul><li>One of ovaries released a ripe ovum </li></ul><ul><li>Ovum enters Fallopian tube </li></ul><ul><li>Tiny hair move the ovum </li></ul><ul><li>Fertilization will occur in the tube. </li></ul>
  42. 50. Ovulation <ul><li>If fertilization occur, the egg and sperm becomes zygote and enters uterus </li></ul><ul><li>Corpus luteum secretes progesterone and oestrogen </li></ul><ul><li>Progesterone will keeps the lining thick for implantation of the zygote </li></ul><ul><li>Zygote will attach to the uterus lining </li></ul><ul><li>Zygote grows and develop into a baby in uterus </li></ul>
  43. 51. Menstruation <ul><li>If no sperm, no fertilization </li></ul><ul><li>Ovum disintegrates and thick uterus lining breaks down </li></ul><ul><li>Broken lining and blood flow out through the vagina </li></ul><ul><li>Menstruation occur, last for 3-5 days. </li></ul><ul><li>Usually menstruation take places place 14 days after ovulation </li></ul>
  44. 52. After Menstruation (before the next ovulation) <ul><li>End of menstruation, ovaries release female sex hormone to thicken the uterus wall again </li></ul><ul><li>Oestrogen causes repair and growth of the uterus lining </li></ul><ul><li>About 12-14 days after menstruation: ovulation take place </li></ul><ul><li>If fertilization occur: pregnant </li></ul><ul><li>If not: menstruation takes place again </li></ul>
  45. 53. Fertile and infertile phases of menstrual cycle <ul><li>Ovum released during ovulation can live for 24-36 hours </li></ul><ul><li>Sperms released into female reproductive system can live for 2-3 days </li></ul><ul><li>If ovulation takes place on day 14, sperms released on day 12 can still fertilized the ovum </li></ul><ul><li>Fertile phase: Day 11-17 </li></ul><ul><li>Infertile phase: the rest of the days </li></ul>
  46. 55. Mating or Copulation <ul><li>Men aroused, blood pumped into penis and filled up the spongy tissues of the penis </li></ul><ul><li>Enter the vagina </li></ul><ul><li>Release semen containing sperm into the vagina </li></ul><ul><li>Only one sperm will fertilize the egg </li></ul>
  47. 56. Family Planning <ul><li>Natural method </li></ul><ul><ul><li>Rhythm method </li></ul></ul><ul><li>Mechanical methods </li></ul><ul><ul><li>Condom </li></ul></ul><ul><ul><li>Diaphragm </li></ul></ul><ul><ul><li>Intra-uterine device (IUD) </li></ul></ul><ul><li>Chemical methods </li></ul><ul><ul><li>Spermicides </li></ul></ul><ul><ul><li>Contraceptive pills </li></ul></ul><ul><li>Surgical methods </li></ul><ul><ul><li>Vasectomy </li></ul></ul><ul><ul><li>Tubal ligation </li></ul></ul>
  48. 59. Sexually Transmitted Disease <ul><li>Syphilis </li></ul><ul><li>AIDS </li></ul>
  49. 60. Syphilis (Caused by Bacteria) <ul><li>Signs and Symptoms </li></ul><ul><ul><li>Pain </li></ul></ul><ul><ul><li>Nausea </li></ul></ul><ul><ul><li>3 stages </li></ul></ul>
  50. 61. Stage 1 Syphilis (Caused by Bacteria) <ul><li>Painless sore </li></ul><ul><li>Occurs in penis/vagina </li></ul><ul><li>Disappear in few weeks without treatment </li></ul>
  51. 62. Stage 2 Syphilis (Caused by Bacteria) <ul><li>Non-itchy skin rashes </li></ul><ul><li>Sores on mouth, throat and genitals </li></ul><ul><li>Disappear after sometime </li></ul>
  52. 63. Stage 3 Syphilis (Caused by Bacteria) <ul><li>Internal organs affected </li></ul><ul><li>Heart failure </li></ul><ul><li>Blindness </li></ul><ul><li>Paralysed </li></ul><ul><li>Death </li></ul>
  53. 64. Prevention and Control <ul><li>Using antibiotics </li></ul><ul><li>No intercourse </li></ul><ul><li>Tracing the contacts </li></ul><ul><li>Wear condom </li></ul><ul><li>Keep to one sex partner </li></ul>
  54. 65. AIDS (Caused by Virus) <ul><li>Virus called HIV </li></ul><ul><li>Destroys the immune system </li></ul>
  55. 66. Signs and Symptoms <ul><li>Chronic fever </li></ul><ul><li>Severe diarrhoea </li></ul><ul><li>Pneumonia </li></ul><ul><li>Cancer of blood vessels </li></ul><ul><li>Brain infection </li></ul>
  56. 67. Mode of Transmission <ul><li>Sexual intercourse with infected person </li></ul><ul><li>Sharing of needles with infected person </li></ul><ul><li>Blood transfusion from infected person </li></ul><ul><li>During pregnancy from infected mother to fetus </li></ul>
  57. 68. Prevention and Control <ul><li>Keep to one sex partner </li></ul><ul><li>Wear condom </li></ul><ul><li>Avoid drug abuse </li></ul><ul><li>Avoid sharing instruments such as razors, toothbrushes </li></ul><ul><li>Acupuncture, piercing or tattooing go to reliable operators </li></ul>