Aims and Objectives

1. Aims and Objectives Describe the passage of sperm from the testis to the fallopian tube; Describe the process of fertilisation and explain its importance in restoring chromosome number and introducing variation; Describe the correct use of condoms; Compare and contrast methods of contraception from biological and ethical viewpoints: the birth control pill, condom, diaphragm, Norplant, DMPA (Depo-Provera), tubal ligation and vasectomy.

6. The Passage of Sperm •  If an egg is passing down the OVIDUCT, fertilization occurs • The egg secretes a chemical that ATTRACTS the sperm • Watch the animation and summarise in your own words the passage of sperm from the testes to the fallopian tubes. • Describe the functions of the seminal vesicles and prostate gland.

7. Fertilization Maximum survival of sperm: up to 5 days Maximum survival of oocyte: 24 h If coitus during fertile period  oocyte fertilization in Fallopian tube.  diploid zygote formed Fertilisation http://www.youtube.com/watch?v=UgT5rUQ9EmQ&feature=related

8. Contraception

9. Contraception birth control pill Condom diaphragm Norplant DMPA (Depo-Provera) tubal ligation vasectomy. Research the different methods of contraception, Include biological and ethical viewpoints of contraception use

11. Summary Sperm are stored in the epididymus and are released into the vas deferens during ejaculation Seminal vesicles and the prostate glands add fluid to the sperm to provide energy and help swimming. During fertilisation the acrosome digests the zona pellucida

12. Barrier Methods of Contraception Male Condom - The male condom is the only method of contraception boys can use. It's really just a rubber tube. It's closed at one end like the finger of a glove so that when a boy puts it over his penis it stops the sperm going inside a girl's body Female Condom - The female condom is a fairly new barrier method. It is not as widely available as the male condom and it is more expensive. It is however very useful when the man either will not, or cannot use a male condom.

13. To use a male condom:  • take the condom out of the packet, taking care not to tear it • place the condom over the tip of the penis • if there's a teat on the end of the condom, use your thumb and forefinger to squeeze the air out of it • gently roll the condom down to the base of the penis • if the condom won't roll down, you're probably holding it the wrong way round: if this happens, throw the condom away because it may have sperm on it, and try again with a new one • after sex, withdraw the penis while it's still erect: hold the condom on to the base of the penis while you do this  • remove the condom from the penis, being careful not to spill any semen • throw the condom away in a bin, not down the toilet

14. Barrier Methods Cont Diaphragms and caps fit inside the vagina and cover the cervix (entrance to the womb). They are barrier methods of contraception and stop sperm meeting an egg.

15. Hormonal Methods of Contraception Contraceptive Pill – It is a pill which the girl takes daily. It contains hormones which prevent pregnancy Contraceptive Patch - It's a thin, beige, sticky patch measuring 5cm x 5cm. It contains the same hormones as the combined pill: oestrogen and progestogen.

16. Hormonal Contraception cont. Contraceptive Implant - The contraceptive implant is a small, flexible tube that's inserted under the skin in the upper arm. It slowly releases a hormone called progestogen and works for three years. Contraceptive Injection - The contraceptive injection contains a hormone called progestogen and is a long-term method of contraception. It's injected into a muscle and the hormone is released very slowly into the body.

17. IUD ‘The IUD’ – which stands for ‘intra-uterine device.’ Most IUDs are now T-shaped. They’re made of plastic and copper, sometimes with a little silver inside. They prevent your partner’s sperms from getting through your womb and into your tubes They alter the secretions (mucus) in your cervix, so creating a further barrier for sperms They affect your womb lining – making it less likely to ‘accept’ an egg.

18. Twins What is the difference between identical twins and fraternal twins?

19. Twins What is the difference between identical twins and fraternal twins?

20. 2. Implantation: Six days after fertilization the blastocyst implants as it burrows into the endometrium. At this point some cells will become the developing embryo and some the placenta. As the trophoblast burrow into the endometrium it causes bleeding (about 10-12 days after fertilization).

22. Implantation The fertilized egg undergoes several division as it is sliding toward the uterus where it implants after about 6 days (unfertilized eggs are destroyed and phagocytized by macrophages) Some cells of the eggs develop into the embryo, other cells form the membrane and placenta. The placental cells start (within 10 days) secreting human chorionic gonadotropin (hCG) hCG has a role similar to LH: it sustains the activity of the corpus luteum (LH level decreases due to negative feedback from progesterone)

23. Pregnancy At 3 months of pregnancy, the placenta secretes large enough amount of estrogen and progesterone to replace the corpus luteum (which then disappears) Estrogen promotes: development of breast duct tissue, breast fatty deposit growth of uterine muscle Progesterone promotes: - mammary gland development - suppress uterine contraction - maintain secretory glands in uterus - lactogen secretion (hormone involved in mammary gland development)

24. Parturition Pregnancy should last 9 months Stretch of the uterus triggers increased contraction and oxytocin release Oxytocin reinforces uterine contraction  Baby’s birth

25. Lactation First few days after birth, secretion of colostrum, a watery liquid rich in proteins. Then, milk is secreted by the mammary glands under the influence of prolactin Milk release is promoted by oxytocin (milk-let-down reflex)

26. Clinical applications: Birth control

27. Placenta (stop after placenta) http://www.youtube.com/watch?v=X-AU6eksyKg&feature=related