Term
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Definition
| primary site of nutient and gas exchange between mother and fetus. 2 components: fetal portion that develops from the chorionic sac. maternal portion that is derived from the endometrium. |
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Term
| Placenta and membrane functions |
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Definition
| protection, nutrition, respiratin, excretion, hormone production. |
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Term
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Definition
| functional layer of endometrium. 3 regions basalis, capsularis, parietalis. |
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Term
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Definition
| part of decidua deep to the conceptus that forms the maternal component of placenta. |
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Term
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Definition
| superficial part of decidua overlying the conceptus |
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Term
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Definition
| all remaining parts of decidua. |
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Term
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Definition
| formed as the endometrium fo uterus is invaded by developing embryo and as the trophoblast forms the villous chorion. |
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Term
| 3 stages of villous Chorion |
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Definition
| primary chorionic villi, secondary and tertiary. |
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Term
| Maternal Component of Placenta |
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Definition
| decidua basalis, from endometrium of uterus located between blastocyst and myometrium. basalis and parietalis are shed as part of afterbirth. capsularis separates from uterine cavity, becomes attenuated and degenerates at week 22 because of reduced blood supply. |
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Term
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Definition
| means falling off or sloughed off. |
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Term
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Definition
| tertiary chorionic villi from trophoblast and extraembryonic mesoderm, which become the villous chorion. |
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Term
| Villous Chorion development |
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Definition
| develops most prolifically at the decidua basalis. thsi is in contrast to development of smooth chorion which is associated with decidua capsularis. |
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Term
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Definition
| many chorionic villi provied a large surface area where matreials may be exchanged across the very thing placental membrane interposed between the fetal and maternal circulations. |
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Term
| Umbilical Artery path through placenta |
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Definition
| at site of placenta these arteries divide into number of chorionic arteries that branch freely in the chorionic plate before entering the chorionic villi. extensive arterio-capillary-venous systems brings fetal blood extremely close to maternal blood. |
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Term
| Maternal Placenta Circulation |
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Definition
| enters intervillous space through 80 -100 endometrial arteris in deciua basalis. vessels discharge into intervillous space through gaps in cytotrophoblastic shell. pulsatile and jetlike. blood is considerably higher pressure thatn that in the intervillous space. As pressure dissipates, blood flows slowly around branch villi, allowing an exchange of metabolic and gaseous products. blood returens through endometrial veins to maternal circulation. |
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Term
| 4 layers of Placentla Membrane |
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Definition
| syncytiotrophoblast, cytotrophoblast, connective tissue of villus, endothelium of fetal capillaries. |
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Term
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Definition
| synthesizes glycogen, cholesterol, fatty acids=>nutrients and energ for embryo/fetus. |
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Term
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Definition
| synthesizes glycogen, cholesterol, fatty acids=>nutrients and energ for embryo/fetus. |
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Term
| Placental Transfer mechanisms |
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Definition
| simple diffusion, facilitated diffusion, active transport, pinocytosis |
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Term
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Definition
| usually characteristic of substancs moving from areas of higher to lower concentration until equilibrium is established. |
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Term
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Definition
| there is transport through electrical charges. |
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Term
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Definition
| agains a concentration gradient requires energy |
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Term
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Definition
| form of endocytosis in which the material beign engulfed is a small sampel of extracellular fluid. |
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Term
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Definition
| O2 and carbon monoxide cross placental membrane by simple diffusion. interuption of oxygen transport for several minutes endagers survival of the embryo. |
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Term
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Definition
| fetus produces small amounts of antibodies because of immature immune system. Gamma antibodies from mother readily transported by pinocytosis. confer immunity to diptheria, smallpox, none to chickenpox (varicella). |
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Term
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Definition
| maternal protein crosses palacental membrane and carries iron to embryo or fetus. |
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Term
| Infectious Agents capable of crossing placenta |
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Definition
| cytomegalovirus, rubella, viruses associated wit varicella, measles, polimyelitis may pass through the placental membrane, and cause fetal infection. |
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Term
| Placental Hormone Production |
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Definition
| human chorionic gonadotropin, human placental lactogen, human chorionic thryotropin, human chorionic adrenocorticotropin, prolactin, relaxin, prostaglandins, progesterone |
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Term
| Maternal surface of placenta |
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Definition
| characterized by 15-20 compartments called cotyledons, which are seperated by decidual septa. dark red in color. |
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Term
| Fetal surface of placenta |
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Definition
| characterized by well vascularized chorionic plate containing the chorionic vessels. smooth and shiny appearance because of amnion. |
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Term
| Umbilical cord structures |
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Definition
| patent opening called primitive umbilical ring on ventral surface of embryo. 3 structures: yolk sac, connecting stalk, allantois. contains umbilical arteries (RL), Umbilical Vein(L), mucus connective tissue (wharton's jelly) |
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Term
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Definition
| not functional in human sand degenerates to form the median umbilical ligament in the adult. 1. as amnion expands it pushes the vitelline duct, connecting stalk, and allantois together to form primitive umbilical cord. week 6 gut tube at yolk sac will herniate into extraembryonic coelom; herniation will be reduced by week 11. gut tube eventually returns to the abdominal cavity; yolk sac and allantois degenerate. |
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Term
| Amniotic Fluid components |
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Definition
| basically water (99%) that contains carbohydrates, lipids, proteins, desquamated fetal cells, and fetal urine. |
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Term
| Amniotic Fluid Production |
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Definition
| constantly produced: dialysis of maternal blood through placenta, dialysis of fetal blood thruogh vessels of placenta and umbilical cord, excretion of fetal urine into the amniotic sac. |
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Term
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Definition
| amniotic fluid is constantly resorbed during preganancy by several possible routes, one of which is the following sequence: fetal swallow, absorbed into fetal blood stream through GI tract, excess amniotic fluid removed via placenta into maternal blood stream. |
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Term
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Definition
| gradually increased from 50 ml at week 12 to 1000ml at term. exchange rate 400-500 ml/hr. new flow of 125-200ml/hr moving from amniotic fluid into maternal blood stream. term fetus excretes 500 ml urine daily mostly water. swallows 400ml a day. |
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Term
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Definition
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Term
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Definition
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Term
| Complete Hydatidiform mole |
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Definition
| a blighted blastocyst (dead embryo) but the trophoblast has hyperplastic proliferation and cystic swelling. cysts form and fill the uterine cavity. |
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Term
| Diagnosis of complete hydatidiform mole |
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Definition
| diagnostic aids include ultrasounds, rising hCG, and development of preeclamsia(hypertension and proteinuria). chromosomes are completely from the father. |
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Term
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Definition
| malignant tumore of the trophoblast. presenst clinically as uterine bleeding. may occur after normal pregnancy, hydatidiform mole, abortion. high hCG levels. metastasizes via the blood stream. |
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Term
| Premature rupture of amniochorionic membrane |
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Definition
| most common cause of premature labor and oligohydramnios. |
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Term
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Definition
| occurs when bands of amniotic membrane encircle and constrict various parts of the fetus, causing limb and craniofacial anomalies. |
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Term
| Presence of one umbilical artery within the cord |
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Definition
| an abnormal condition that generally indicates the presence of cardiovascular anomalies. |
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Term
| Abnormal placental shapes |
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Definition
| velamentous placenta, bipartitie or tripartite placenta, duplex or triplex placenta, membranous placenta. |
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Term
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Definition
| placenta is attached close to or covering the cervix. |
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Term
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Definition
| premature separation of placenta from implantation in the uterus. |
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Term
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Definition
| antibodies from Rh - mother enter blood stream of Rh + infant, damagin red blood cells. infant responds by producing immature rbc with nuclei. |
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Term
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Definition
| may result fro mfetal urinary tract anomalies that include bilateral renal agenesis, posterior urethral valves, and bilateral multicystic dysplastic kidneys. |
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Term
| Oligohydramnios signs and symptoms |
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Definition
| nonrenal etiologies include intrauterine growth retardation, post-term pregnancy, fetal demis, and rupture membranes. lungs are hypoplastic and neonates who survive delivery die of respiratory failure. |
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Term
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Definition
| may result from failure of fetus to swallow and absorb amniotic fluid in normal amounts. this may occur as a result of GI disorders, neurological problems, and a variety of others. |
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Term
| signs and symptoms of polyhydramnios |
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Definition
| mild hydramnios often has no symptoms, breathlessness, abdominal pain, swelling or bloating which may indicate more severe hydramnios |
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