Details Title: 2 week of development Description: 2nd week of Human Development Total Flash Cards: 20 Created: 01/21/2009 15:38:55		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Science Flashcards
Cards in this set: Term Cytotrophoblast Definition mononucleated layer of cells that is mitotically active forms new trophoblast cells that migrate into increasing mass of syncytiotrophoblast where they fuse and lose their cell membranes Term Syncytiotrophoblast Definition a rapidly expanding, multinucleated mass in which no cell has boundaries. produces hCG which maintains corpus luteum Term Hcg functions Definition produced by syncytiotrophoblast and enters maternal blood in lacunae. maintains activity of corpus luteum in ovary. Basis of pregnancy test Term Exocoelomic Membrane Definition becomes the primary yolk sac Term Yolk Sac Definition extraembryonic mesoderm increases and isolated spaces appear within it which fuse to form a large cavity called extraembryonic coelom. Term Lacunae Definition appear in syncytiotrophoblast.filled with mixture of maternal blood from endometrial capillaries and secretions from eroded uterine glands. Term Corpus Luteum Definition secretes estrogen and progesterone to maintain the pregnancy Term Uteroplacental Circulation Definition when maternal blood flows into lacunae, oxygen and nutritive substances become available to the embryo. Term Decidual Reaction Definition endometrial connective tissue undergo transformation by accumulating glycogne and lipid in the cytoplasm...allows immunological privilege to conceptus Term Human Chorionic Gonadotropin Definition 57,000 MW with alpha beta subunits produced by syncytiotrophoblast. enters maternal blood circulation. prevents degeneration of corpus luteum. Term Oncofetal Antigens Definition cell surface antigens that normally appear only on embryonic cells but also express themselves in human malignant cells. Term Carcinoembryonic Antigen Definition glycoprotein involved in cell adhesion. Normally producedduring fetal development, butproduction stops before birth. used to determine recurrences of carcinomas after surgery Term Alpha-fetoprotein Definition produced by liver and yolk sac. high levels may indicate and abnormal development. may be produced by some tumors as well. Term RU-486 Definition induces abortion if taken during first 3 months of pregnancy. blocks the action of progesterone. usually taken with prostaglandin. Term Placenta Previa Definition causes vaginal bleeding (antepartum haemorrhage) placenta implants over the cervix Term Risk of Placenta Previa Definition Previous placenta previa, caesarean delivery, or abortion. -Women who are younger than 20 are at higher risk and women older than 30 are at increasing risk as they get older. -Women with a large placentae from twins. -Women who smoke or use cocaine may be at higher risk. Term Inhibition of Implantation Definition estrogens can prevent implantation of blastocyst but not fertilization. *Diethylstilbestrol Term IUD intrauterine device Definition inside uterus through vagina and cervix interferes with implantation causing inflammatory reaction. some have progesterone. Term Placenta as allograft Definition protection of conceptus involves down-regulation of MHC class I antigen expression on trophoblast. immunosuppresive environment of uterus. Term Decidual cell protection of conceptus Definition produce locally active immunosuppressor molecules like prostaglandins E2 which prevent activationof the cells and NK cells within decidua.