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

3. Male Reproductive System testis epididymis vas deferens (sperm duct)

4. Testes and Epididymis Sperm cells are haploid and are produced in the seminiferous tubules within the testes. From the testes they are deposited into the epididymis and then vas deferens to begin swimming and prepare to be deposited into the female.

5. Male Accessory Glands seminal vesicle prostate gland Cowper ’ s gland secrete seminal fluid

6. Functions of Seminal Fluid To provide a medium for the sperms to swim To activate and nourish, fructose, the sperms To neutralize the acidity in the female reproductive tract

7. Male Reproductive System urethra penis

8. Penis Erected during copulation for insertion into vagina –Dilation of arterioles causes the erectile tissue of penis become turgid –Smooth muscles of vas deferens and epididymis contract –Semen is squeezed from the penis to the top of vagina Ejaculation

9. Female Reproductive System Video of fertilization vagina cervix uterus oviduct ovary

10. Functions of Ovary For production of female gametes (ova/eggs) For production of female sex hormones, oestrogen and progesterone, which controls the female reproductive cycle and secondary sex characteristics

11. Oviduct/Fallopian Tube Carries the ovum forward by –the beating action of the cilia on its inner surface –the contraction of muscles of oviduct, or fallopian tube.

12. Ovulation The release of an ovum from an ovary (1) follicle will release estrogen (2) estrogen high level will trigger hypothalamus to stimulate pituitary to release more LH (luteinizing hormone) and FSH (follicle stimulating hormone) (3) high LH stimulates release an ovum Video of ovulation

13. Menstrual Cycle Once in about 28 days The uterine lining, endometrium, becomes thickened 14 days after ovulation to prepare for the fertilized ovum to implant in it

14. Menstrual Cycle Day 1 – 5 –Begins when hypothalamus stimulate pituitary to release LH and FSH –Uterine lining decreases in thickness to a minimum

15. Menstrual Cycle Day 6 - 14 –LH stimulate follicle to release ovum –Lining becomes thicker with increased blood supply –Day 14 : ovulation

16. Menstrual Cycle Day 14 - 28 –Lining remains thick to ready for implantation of fertilized ovum –Corpus luteum release estrogen and progesterone

17. Menstrual Cycle Day 28 –No implantation of fertilization ovum –Uterine lining breaks down; menstruation starts

19. Egg maturation in ovary Corpus luteum –produces progesterone to maintain uterine lining

20. Events Happened after Fertilization The zygote undergoes cleavage and after the 4 th day it becomes a solid ball of cells called morula The morula continues to divide and forms a hollow ball of cells called blastocyst After reaching the uterus, the blastocyst fix firmly onto the thick uterine wall  Implantation

21. Development of Human Fetus uterus fetus placenta umbilical cord amnion amniotic fluid Video on fetus development

22. 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

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

24. The Placenta oxygenated blood from mother ’ s artery villis umbilical vein umbilical artery deoxygenated blood to mother ’ s vein

25. Functions of the Placenta As a place of exchange of materials between mother and the fetus For secreting hormones Let’s summarize…..

26. 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

27. Adaptations of the Placenta Maternal blood is separated from fetal blood by capillary wall –to prevent high pressure of maternal blood to break the delicate fetal blood vessels –to prevent harmful substances to enter the fetus –to prevent clotting of maternal and fetal blood if their blood groups are incompatible

28. The Birth Process Onset of labour –Uterine muscles begin to make rhythmic contractions –Contractions gradually become stronger and closer

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

31. 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

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

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

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

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

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

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