Biology 110 FINAL

19 flashcards · Biology · by Demi Burns

1. The blood in the fetal and maternal circulations does not mix.

2. The first event of pregnancy is implantation.

3. The lining of the uterus is called the endometrium.

4. The endometrium creates endometrial glands that secrete to the implanted embryo to provide nourishment.

5. The placenta is how the mother and the baby exchange nutrients/gases/wastes in the uterus.

6. The placenta's fetal portion contains chorionic villi that provides a large surface area for gas and nutrient/waste exchange.

7. First trimester- organs develop

8. Second trimester- rapid growth phase

9. Third trimester- lungs mature to function on their own at birth and the fetus positions itself above the cervix

10. Estradiol from the placenta readies the uterus for a response to oxytocin.

11. The fetus's head pushing against the cervix activates stretch-sensitive sensory neurons that send stimulatory signals to the mother's hypothalamus.

12. The hypothalamus stimulates secretion of oxytocin from the posterior pituitary.

13. Oxytocin stimulates stronger uterine contractions.

14. Prostaglandins secreted by the uterus also enhance contractions. Sensory input to the hypothalamus is further enhanced as stronger contractions continue to activate stretch receptors.

15. Veins are oxygenated, and bring that blood to the baby

16. Arteries are dioxygenated, and carry blood away from the baby's heart.

17. The mother sends blood through maternal arteries.

18. The more receptors there are, the more sensitive something is.

19. High levels of estradiol increases the amount of oxytocin receptors= higher sensitivity to oxytocin