Understanding Embryonic Development and Pregnancy

1. Embryonic development and Pregnancy

2. Embryonic development and Pregnancy • Another term for pregnancy is the gestation period • It lasts for about 280 days which is slightly more than 9 months

4. Embryonic development and Pregnancy • Embryo increases in shape and size as it grows • By 12 weeks the embryo has grown quite a lot, and will look clearly like a human baby • It is now called the foetus

6. Development of the extra-embryonic membranes

7. Development of the extra-embryonic membranes • Soon after the blastocyst itself to the uterus wall, 2 membranes develop around it • Extra-embryonic membranes

9. Development of the extra-embryonic membranes • These membranes are: • The chronian on the outside, forms chronic villi • An amnion, on the inside, with amniotic cavity filled with amniotic fluid

12. Development of the extra-embryonic membranes • Chronic villi with uterine tissue make up the placenta • A hollow rope-like tube called umbilical cord, attaches the embryo to the placenta

13. Development of the extra-embryonic membranes • The placenta has the following functions: • Attachment of embryo to mother • Diffusion of desolved food from mother to foetus

14. Development of the extra-embryonic membranes • Diffusion of oxygen from mother to foetus • and carbon dioxide from foetus to mother

15. Development of the extra-embryonic membranes • After 12 weeks of pregnancy it secretes its own progesterone which maintains pregnany

16. Development of the extra-embryonic membranes • The amniotic fluid has the following functions: • Shock absorber • Prevents dehydration

18. Development of the extra-embryonic membranes • Keeps foetus within a small temperature range • Allows free foetal movement for growth and development

19. Development of the extra-embryonic membranes • The umbilical cord contains the umbilical artery and vein • The artery carries deoxygenated blood with nitrogenous wastes from the embryo to the placenta • The vein carries oxygenated blood and food

20. Birth • Occurs about 280 days after fertilisation, this happens in 3 stages • Stage 1: • Uterus contracts • Head pushed against cervix • Membranes break • Cervix dilates

21. Birth • Stage 2: • Baby forced out through birth canal • Umbilical cord cut • Baby handed to mother • Stage3: • Placenta becomes loose • Placenta pushed out as the ”after-birth

22. Contraception

23. Contraception

24. Contraception

25. Contraception

26. syphilis • Caused by spiral bacterium, treponema pallidum • Transmission: • Sex with infected partner, mother to child • Symptoms: • Nodules on sex organs • Rash over the body • Sore throat and aching muscles

27. syphilis • Can attack tissue or organ including skin • Lead to blindness and death • Treatment: • Antibiotics in early stages

28. gonorrhoea • Causes: • Coccus bacterium, gonococus • Transmission: • Sex with infected person • Symptoms: • Frequent and painful urination, discharge • Sterility in men and woman

29. gonorrhoea • Treatment: • Antibiotics, penicillin • More difficult to cure in late stages

30. Prevention of stds • Most stds are life-threatening • For many of them, there is no cure • Medication, nutritious diet and healthy lifestyle can slow down progress of the disease • Use A B C method • Abstain from sexual activites • Be faithful to your partner • Condomise