Reproduction

1. Human Reproduction

2. Sexual Reproduction in Human testis ovary sperms eggs (ova) fertilization zygote Blastocyst embryo fetus baby

4. External Male Reproductive Organs • Penis • Testes • Scrotum

5. The Penis • Tube-shaped organ that extends from trunk of the body just above the testes • Part of the body where semen is released (ejaculation) • Semen- thick fluid containing sperm and other secretions from the male reproductive system

6. Male Reproductive System Scrotum – sac of skin that holds testes. Hangs below body to keep testes cool. Sperm cannot be produced if body is too warm. Testes move into scrotum just before birth. Testis/testes –Made up of small, coiled tubes seminiferous tubules. 300-600 per testis. Immature sperm made here. • Secrete testosterone

7. Testis and epididymis epididymis vas deferens (sperm duct) sperm tubules

8. Internal Male Reproductive Organs • Epididymis • Vas Deferens • Seminal Vesicles • Prostate Gland • Cowpers Gland • Urethra

9. Epididymis • For temporarily storage of sperms • Where sperm Mature • During intercourse, muscles of epididymis contract to release sperms

10. Internal Organs Vas deferens– tubes that extend from each epididymis to the urethra Cowper’s gland, Prostate Gland, & Seminal vesicles–secretions from these glands combine with sperm-containing fluid to form semen

11. Male Reproductive System seminal vesicle secrete seminal fluid prostate gland Cowper’s gland

12. Functions of Seminal Fluid • To provide a medium for the sperms to swim • To activate and nourish the sperms • To neutralize the acidity in the female reproductive tract Seminal Fluid Semen Sperms +

13. Male Reproductive System 8. Urinary bladder – stores urine 9. Rectum- holds waste 10. Urethra – passageway for excretion of urine and sperm to leave body. Vas deferens empties into urethra

14. Male Concerns • Hernia- Part of body pushes through the muscle wall • Sterility- Sperm weak, may not be able to fertilize egg • Prostate Cancer- Uncontrolled growth of cells (radiation therapy/removal of prostate) • Testicular Cancer- Frequent in males 15-35 (self-check)

15. Preventing Problems • Prevent STI’s • Prevent trauma (athletic cups) • Prevent hernias (don’t lift things that are too heavy)

17. Male Reproductive System Urinary Bladder Seminal Vesicles Prostate Gland Urethra Penis Rectum Epididymis Cowper’s gland Testes Vas Deferens Scrotum

19. Functions of Ovary • Produce female gametes (ova/eggs) • For production of female sex hormones • Estrogen and Progesterone

20. Ovary • A female’s ovaries contain 400,000 immature eggs at birth. (all the eggs they will ever have) • Once a month during puberty, a mature egg is released into the fallopian tubes. This process is called ovulation.

21. Fallopian Tubes • Carries the ovum (egg) forward by • the beating action of the cilia on its inner surface • the contraction of muscles of fallopian tube

22. Female Reproductive System Fallopian tube – Each ovary is near but not connected to oviduct. Tube with funnel-like opening. Cilia line it to create a current that draws the egg into the tube. Egg is fertilized in the fallopian tube 3. Uterus – thick, muscular, pear-shaped organ. Once egg is fertilized it finishes its development in uterus attached to uterine wall

23. Female Reproductive System Urinary bladder – storage of urine Urethra – passage of urine to outside of body Vagina (birth canal) – leads to outside of body from the uterus Cervix – narrow neck of uterus Rectum – passage for wastes

24. Ovulation • The release of an ovum (egg) from an ovary • Every month, the fallopian tubes take turns releasing an egg. Right one month, left the next month

25. Female Reproductive System Fallopian tube ovary uterus cervix vagina

26. Menstrual Cycle • Menstruation occurs once a month, due to the uterus preparing itself for possible pregnancy. • If pregnancy doesn’t occur, the uterine lining breaks down into blood, tissue, and fluids and is released through the vagina.

28. Female Concerns • Infertility- Inability for female to become pregnant • Problems that can cause infertility • STD’S--PID Infection of the Fallopian Tubes • Blocked Fallopian Tubes- PID, Abdominal Surgery, Leading Cause Of Infertility • Endometriosis- Uterine tissue grows outside the uterus, often appearing on the ovaries, fallopian tubes and abdominal cavity

29. Other Female Reproductive Disorders • Vaginitis: Most common Vaginal infection in women of child bearing age. Caused by bacteria, accompanied by discharges, pain, itching… • Ovarian Cysts: Fluid filled sacs on the ovaries. Small and non-cancerous, usually they will disappear on their own. Larger cysts may require surgery

30. Preventing Problems • Prevent STD’s • Prevent vaginal irritation • Bathe regularly • Exercise regularly

31. Events Happened after Fertilization • Egg is fertilized in fallopian tubes • Fertilized ovum is carried to the uterus by • the beating cilia on the inner wall of oviduct • the contraction of muscles of fallopian tube • After reaching the uterus, the fertilized ovum fixed firmly onto the thick uterine wall----Implantation

32. Development of Human Foetus uterus fetus placenta umbilical cord amnion amniotic fluid Video on foetus development Click here

33. Functions of the Uterus • During embryo development • Protect the embryo • Provide a constant environment for the embryo to develop • Allow placenta to attach on • During birth of baby • Push the baby out by muscular contraction Click here

34. Functions of the Amniotic Fluid • To keep the foetus moist to prevent dessication • As a water cushion to • support the foetus • allow it to move freely • absorb shock • protect the foetus from mechanical injuries • To reduce temperature fluctuation • To lubricate the vagina during birth Click here

35. The Placenta oxygenated blood from mother’s artery deoxygenated blood to mother’s vein villus umbilical vein umbilical artery

36. Functions of the Placenta • As a place of exchange of materials between mother and the foetus • For secreting hormones

37. Adaptations of the Placenta • Finger-like villi • to increase the surface area for efficient diffusion • Maternal blood and fetal blood flows in opposite direction • to speed up diffusion of materials between them • Maternal blood capillaries and fetal blood capillaries are separated by thin membrane • to shorten the distance of diffusion of materials

38. Adaptations of the Placenta • Maternal blood is separated from foetal blood by capillary wall • to prevent high pressure of maternal blood to break the delicate foetal blood vessels • to prevent harmful substances to enter the foetus • to prevent clotting of maternal and foetal blood if their blood groups are incompatible Click here

39. The Birth Process • Onset of labor • Uterine muscles begin to make rhythmic contractions • Contractions gradually become stronger and closer

40. The Birth Process • Uterine contractions causes amnion to break and amniotic fluid to escape out of the vagina • Muscular contractions push the foetus head first through the vagina, and the umbilical cord is cut and tied • Further contractions push the placenta out of the body • “After birth” • Dilation of cervix allow the head of the foetus to pass through

41. Could you survive after birth without the care of your parents?

42. Parental Care • To increase the chance of survival of the young • Mother feeds milk to the baby • Milk provides the babies with a balanced diet • It also contains antibodies which defend the babies against infection

43. Birth Control • Human population increases exponentially • leads to storage of resources • problem of pollution becomes more serious • overcrowding

44. Using contraception methods What can we do?

45. Rhythm Method • Prevent copulation during 7 days before and after ovulation (fertile period)

46. Condom • Male and female condom • As a barrier to prevent sperms from entering the vagina

47. Diaphragm • Fitted over the cervix • To be used together with spermicides

48. Contraceptive Pills • Contains hormones which inhibit ovulation • Must be taken regularly • May have side effect

49. Surgical Methods Tubal ligation Cutting and tying of oviducts Vasectomy Cutting and tying of sperm ducts