ATI OB – Peds Study Guide 1

ATI OB – Peds Study Guide 1 1. The menstrual cycle (Hypothalamic-Pituitary cycle)- from PowerPoint a. Results from a functional hypothalamic-pituitary-ovarian axis and a precise sequencingof hormones that lead to ovulation. b. End of the menstrual cycle- estrogen and progesterone decrease c. Hypothalamus is stimulated and secrete GnRH which stimulate anterior pituitary gland tosecrete FSH which stimulates development of ovarian Graafian follicles which produce estrogen d. Estrogen level decreases e. GnRH stimulate the anterior pituitary gland to release LH (day 12) expels the ovum (24to 36 hours) No fertilization regression of the corpus luteum f. Progesterone and estrogen decrease menstruation 2. Fertilization and implantation of the fertilized ova- from PowerPoint a. Fertilization i. Fertilization occurs in the ampulla (outer third) of the fallopian tube ii. Zona pellucida- zone reaction; no other sperm can penetrate the fertilized egg iii. Mitosis/cellular replication-zygote travels down the fallopian tube and embedsinto the uterus (3-4 days) iv. Rapid cellular division; implantation occurs 7-10 days post conception v. Mitosis/cleavage- 4 cleavage; 16 cleavage vi. Morula- solid ball of 16 cells (72 hrs implantation in the fallopian tube) vii. Blastocyst- inner cell mass from the embryo and amnion 1. Implant in the upper uterine wall- rich blood supply; strong musclefibers; thick lining viii. Trophoblast- outer cell mass from the chorion and placenta b. Implantation i. Contact between growing structure, uterine endometrium, occurs 8-10 days afterfertilization ii. Blastocyst embeds in the endometrium (6-10 days post conception) iii. Can have implantation bleeding iv. Development of the chorionic villi v. Endometrium is known as the decidua 1. Decidua basalis, decidua capsularis, and decidua vera