Home > Flashcards > Women's & Gender Studies > implantation & endro of pregna

Details Title: implantation & endro of pregna Description: 4.24.07 Total Flash Cards: 50 Created: 04/29/2007 08:52:33	To study from this set of flash cards, or to create your own your own study flash cards, register HERE. If you are already a registered user, CLICK HERE.
Cards Term What is the point of discussing implantation and endocryn of preg? Definition to understand the establishment of a receptive state of a human embryo, which absolutely depends upon the exposure of the tissue to appropriate levels of steroid horomones Term what's the point of the endometrial biopuy? Definition to assess endometrial maturation Term what happens 1 week post ovulatory? Definition morphological changes--such as mitoses, basal vacuolation, and secretion Term what happens during the second week post ovulatory? Definition stromal changes--edema, predecidual reaction, and leukocyte infiltration Term when is the endometrium considered out of phase? Definition when menses occurs more than 2 days before or after the time indicated by endometrial histology Term where do most implantations occur? Definition in the posterior endometrium Term why might implantation fail? Definition due to deficient plasma concentrations of steroid horomones or bc of decreased responsiveness of the endometrium to appropriate levels of horomones, there might be a delay in the establishment of a receptive state, thus implantation might fail even though a potentially normal embryo is still present in the endometrial cavity Term at what state do embryos enter the uterine cavity? Definition in the morula stage (2-3 days following fertilization) Term what must happen for normal implantation and development to occur? Definition synchronous development of the embryo and endometrium Term what is uterine receptivity? Definition the temporal window of endometrial maturation during which the trophectoderm of the blastocyst can attach to the endometrial epithelial cells and subsequently invade the endometrial stroma. Term what is the transition from the non-receptive to receptive endometrial state determined by? Definition the regulated expression of membrane bound, soluble, or secretory factors Term nidation Definition implantation Term what must happen to the ZP for the embryo to extrude from it? Definition it must be completely or partially degraded Term what happens during nidation and placentation? Definition trophoblasts adhere and migrate within the endometrial stroma and finally invade the maternal vessels and thus establish the hemochorial placenta. this process involves cell-cell and cell-substratum interactions involving both degredation of the matrix to allow migration of the cells and matrix remodeling. Term what 2 layers make up the endometrium? Definition the basalis and functionalis layers Term do you shed the basalis layer during menstruation? Definition no Term what does the basalis layer contain? Definition the epithelial, stromal, and vascular progenitor cells responsible for proliferation and neovascularization of the endometrium during the PROLIFERATIVE phase, under the regulation of ESTROGEN (mainly estradiol). Term what is in the functionalis layer? Definition it's the top 2/3 of full thickness endometrium--shed during menses Term what is the role of the prolif phase? Definition it's the ochestrator of cellular proliferative activity Term what horomones are involved in prolif? Definition estrogen ONLY Term what horomone in secretory phase? Definition progesterone Term what happens during the secretory phase? Definition no change in thickness, a differentiation of epithelial and stromal cells. Term what happens if no pregers? Definition regression of the corpus luteum, and the fuctionalis layer breakdown results in menses Term wha are the minimal endocrine "needs" for normal cycling of the endometrim? Definition prolif--estrogen, secre--progesterone. menses--withdrawl of progest Term what is endometrial receptivity? Definition the period of endometrial maturation, which permits the attachment of the embryo and the establishment of pregnancy Term How do we know the human embryo is very "adhesive" and "invasive"? Definition ectopic pregnancy (embryo attaching in fallopian tubes, on yhr prtiyonrsl duthsvr, even on/in the ovary) Term what is required for the endometrium for implantation? Definition a DEFINED period that the embryo can adhere and successfully implant Term what horomone is critical for the development of the receptive endometrium? Definition progesterone Term what maintains early pregnancy? Definition progest and estrogen from the corpus luteum (In the ovary, the corpus luteum secretes estrogens and progesterone, which are steroid hormones responsible for the thickening of the endometrium and its development and maintenance, respectively.) If fertilized, however, the placenta secretes the hormone human chorionic gonadotropin (hCG) or a similar hormone in other species. This hormone signals the corpus luteum to continue progesterone secretion, thereby maintaining the thick lining (endometrium) of the uterus, and providing an area rich in blood vessels in which the zygote(s) can develop. From this point on, the corpus luteum is called the corpus luteum graviditatis. The introduction of the hormone prostaglandin at this point causes the degeneration of the corpus luteum and the abortion of the fetus. However, in placental animals such as humans the placenta eventually takes over progesterone production and the corpus luteum degrades into a corpus albicans without embryo/fetus loss. Term what is the window of implantation in the human? Definition days 20-24 Term at what stage of embryo development does implantation occur? Definition blastocyst (day 7) Term WHAT IS HATCHING driven by? Definition the embryo, not the mother Term talk about the role of the embryo (blastocyst) Definition In the post-implantation phase, the blastocyst secretes a hormone named human chorionic gonadotropin which in turn, stimulates the corpus luteum in the woman's ovary to continue producing progesterone. This acts to maintain the lining of the uterus so that the embryo will continue to be nourished. The glands in the lining of the uterus will swell in response to the blastocyst, and capillaries will be stimulated to grow in that region. This allows the blastocyst to receive vital nutrients from the woman. Term what is embryo hatchign? Definition ZP is dissolved by enxymes elaborated by the developing embryo Term what happens after hatching? Definition the embryo becomes fully embeddged in the endometrium by day 7 following the initiation of implantation (day 12-14 post ovulation) Term what are 4 phases of implantation? Definition apposition, adhesion, intrusion, and invasion Term apposition Definition hatched blastocyst is positioned in apposition to the endometrial epithelial cells Term adhesion Definition trophoblast cells adjacent to the ICM adhere to the apical surface of the endometrial epitehlial cells Term intrusion Definition trophoblast cells insinuate themselves in btw the endometrial epithelial cells Term invasion Definition trophoblast cells, and whole embryo, invade THROUGH THE BASEMENT MEMBRANE and the endometrial stroma and reasch and invade the maternal vessels. Term what molecules and enzymes are involved in implantation? Definition cell adhesion molecules (CAM), and ECM probably plays a role in invasion and remodeling. ENZYMESL MMP-9 (92kd collagenase), urokinase type plasminogen activator Term what does secreting ECM do? Definition during implantation and placentation, there in invasion of the maternal stroma and blood vessels and remodeling Term why is comparing cancer and implantation not apt? Definition trophoblast invasion is a REGULATED process with SPECIFIC factors involved in triggering and the arrest of the process. cancer is UNREGULATED Term what are the 2 steps of invasion and placentation? Definition colonization of blood velses (tropho cells invade maternal spiral arteries of the endometrium and replace the endothelial cells); and hemochorial placentation (direct contact of maternal blood (heme) and trophoblast cells (chorion)). Term how are the umbilical vessels formed? Definition In the end, at the core of each villus, there are fetal cappilaries adjacent to the trophoblast layer and coalesce to form the umbilical vessels. Term what are cytotrophoblasts? Definition mitotically active progenitor trophoblast cells, which give rise to terminally differentiated SYNCYTOTROPHOBLAST cells lining the outer surface of chorionic villi and come into direct contact with maternal blood. Term wher eare Trophoblasts derived from? Definition the trophectoderm of the blastocyst Term what are the 2 trophoblast functions? Definition 1. endocrine fuction (hCG and P4 (and E) secreted mainly by the syncytiotrophoblast and 2. exchange of nutrients and gases btw mother and fetus Term what happens to the cytotrophoblast layer later in the pregnancy? Definition it becomes attenuated (Attenuation is the reduction in amplitude and intensity of a signal. ) Term is the trophoblast invasion critical? Definition yes--it's been implicated in the development of both maternal and fetal complications later in pregnancy.