1. Fertilization and Early Development Campbell, N. 1999 Biology. United States: Benjamin Cummings Publishing Company.

2. Fertilization Fertilization or Syngamy Union of haploid gametes (egg/ova and sperm) to form a zygote takes place in the fallopian tube The egg is fertilized in the oviduct, the resulting zygote travels down into the uterus.

3. Pregnancy and Development Gestation is divided into three trimesters. First trimester Second trimester Third trimester

4. Hormonal Control of Pregnancy During the first trimester the embryo secretes a hormone indicating its presence, HCG (sometimes excreted in the urine-pregnancy tests) HCG acts like the pituitary LH maintaining progesterone and estrogen secretion through the first trimester: Increased mucus secretion in the cervix Growth of placenta Cesation of ovulation and menstrual cycle (- feedback)

5. First Trimester Cleavage: begins 24 hrs. after fertilization. Blastocyst: About after fertilization a mass of cells or blastocyst is formed. Implantation: 7 days after ovulation the blastocyst implants in the endometrium. The endometrium responds by growing over the blastocyst. Tissue grows from the embryo joining the endometrium and forming the placenta. Organogenesis (fetus); period of extensive development and radical change for both mother and baby). Example: heart beats by the fourth week; by the end of the eight week all the organs are present in rudimentary form

6. Second Trimester Rapid growth of fetus Movement Hormonal levels stabilize as HCG declines. Placenta secretes its own progesterone Corpus luteum deteriorates

7. Third Trimester Fetal activity decreases as fetus fills available space in the embryonic membranes Mother’s abdominal organs become compressed and displaced resulting in frequent urination and digestive blockage

8. Hormonal Control of Birth Progesterone is needed to facilitate implantation Birth or parturition occurs through a series of strong, rhythmic contraction of the uterus, commonly called labor. Prostaglandins from the uterus, oxytocin from the Posterior Pituitary and nervous reflexes all regulate labor contraction

9. Stages of Labor First stage of labor. The opening of the cervix thins out and dilates. Complete dilation of the cervix ends the first stage of labor Second stage is birth. The uterus is firmly attached to the floor of the abdomen. Continuous contractions force the fetus down and out the uterus and vagina Final stage. Expulsion of the placenta.

10. Fetal Development List and describe embryonic membranes Explain how the exchange of materials between mother and fetus takes place Oral Presentation (see due date) Genetic screening and assisted fertilization techniques (I.e IVF, GIFT) Research Paper (TBA) Describe four methods of family planning and contraception Discuss ethical issues associated with family planning and contraception