Practice Quiz - Development of the Placenta and Extraembryonic Membranes
The umbilical cord may loop around the fetus or become knotted, which may cause fetal distress. true false
When the amount of amniotic fluid exceeds two liters, the condition is called: oligohydramnios polyhydramnios or hydramnios amniotitis bag of waters hydrogravida
The wall of the chorionic sac is composed of: cytotrophoblast and syncytiotrophoblast two layers of trophoblast lined by extraembryonic somatic mesoderm trophoblast and exocoelomic membrane extraembryonic splanchnic mesoderm & both layers of trophoblast none of the above
The most distinctive characteristic of a primary chorionic villus is its: outer syncytiotrophoblastic layer cytotrophoblastic shell extraembryonic somatic mesodermal core bushy appearance cytotrophoblastic core
Chorionic villi are designated as secondary chorionic villi when they: contact the decidua basalis are covered by syncytiotrophoblast develop a mesenchymal core give rise to branch villi none of the above
When chorionic villi become vascularized they are called ____ villi. branch stem tertiary anchoring mature
The most important region of the decidua for the nourishment of the conceptus is the decidua _______. frondosum capsularis parietalis basalis laeve
The intervillous space contains all of the following substances EXCEPT: oxygen carbon dioxide maternal blood cells fetal blood electrolytes
Which of the following materials usually do not cross the placental membrane or barrier? free fatty acids steroid hormones bacteria vitamins viruses
The tissue of the four-week embryo that lies in contact with the decidua basalis is: cytotrophoblast shell syncytiotrophoblast villi chorion laeve extraembryonic somatic mesoderm all of the above
At or near term, the intervillous space has a total volume of: 150 ml 400 ml 500 ml 1000 ml 1500-2000 ml
The primary source of fetal energy is: the fetal intestines the placenta amniotic fluid maternal fat
The portion of the decidua which does not survive until the end of pregnancy is the: capsularis basalis laeve parietalis frondosum
Attachment of the umbilical cord to the fetal membranes instead of to the placenta is called: battledore placenta Wharton's placenta velamentous insertion cotyledon placenta eccentric insertion
Amniotic fluid IS NOT concerned with: regulation of fetal temperature exchange of fetal wastes protection of the conceptus early nutrition of the embryo
Which of the following is NOT true concerning decidua basalis: lies between the villous chorion and the myometrium forms the "roof" of the placenta supplies blood to the intervillous spaces is partially composed of fetal tissues
Mechanisms involved in placental transfer of material include: facilitated diffusion pinocytosis active transport simple diffusion all of the above are correct
Which of the following is NOT true concerning the umbilical cord? it usually attaches near the center of the placenta it may not be attached to the placenta it normally contains two arteries and one vein it may form a knot that can cause fetal distress it contains cardiac jelly
The chorionic sac surrounds the embryo, amniotic sac and yolk sac. true false
Which of the following is NOT a component of the mature placental barrier? the endothelial lining of fetal capillaries the cytotrophoblast the syncytiotrophoblast the basement membrane of fetal capillaries all of the above are part of the mature placental barrier
Which is NOT true concerning the human placenta: is divided into a number of cup-like compartments by incomplete septae of maternal tissue has an intervillous space filled with maternal blood and lined by syncytiotrophoblast has chorionic villi as functional units is anchored to maternal tissue by columns of syncytiotrophoblast
In placenta praevia, the placenta may detach and cause severe bleeding and fetal anoxia during delivery. true false
The human placenta: has a maternal component formed by the decidua capsularis shows no changes with age retains the cytotrophoblast layer of the placental barrier throughout gestation has chorionic villi as the structural and functional unit
The placental intervillous space: is divided into compartments by the placental septa is a continuous space throughout the
placenta is lined by syncytiotrophoblast contains circulating maternal blood all of the above are correct
Under normal conditions, the placenta acts as a barrier against: transfer of drugs and their metabolites transfer of all infectious agents transfer of nutrients mixing of maternal and fetal blood transfer of hormones
Human chorionic gonadotropin (HCG) is produced by the: syncytiotrophoblast anterior pituitary gland theca folliculi corpus luteum of pregnancy embryoblast
Which of the following materials usually cross the placental membrane? free fatty acids steroid hormones drugs and chemicals with a molecular weight of less than 500 vitamins all of the above
Which structure is responsible for transport of nutrients to the fetus? cytotrophoblastic shell trophoblast decidua basalis cotyledon spiral artery intervillous space tertiary villus umbilical artery umbilical vein syncytial knots vitelline duct chorion frondosum amnion
Which structure is found in the umbilical cord, but is not part of the fetal circulatory system? cytotrophoblastic shell trophoblast decidua basalis cotyledon spiral artery intervillous space tertiary villus umbilical artery umbilical vein syncytial knots vitelline duct chorion frondosum amnion
Which of the following structures should normally be found as a pair? cytotrophoblastic shell trophoblast decidua basalis cotyledon spiral artery intervillous space tertiary villus umbilical artery umbilical vein syncytial knot vitelline duct chorion frondosum amnion
What is the maternal and fetal portions of the placenta respectively? villous chorion / decidua basalis decidua basalis / villous chorion anchoring villi / cytotrophoblastic shell
Which poisonous gas can cross the placental membrane? carbon monoxide oxygen carbon dioxide methyldopa
There are three circulatory shunts in fetal circulation. Which one allows blood from the placenta to bypass the liver? ductus arteriosus foramen ovale ductus venosus foramen seccundum arteriovenous fistula
Erythroblastosis fetalis occurs due to what? AB incompatibility Rh+ baby born to Rh- mother In utero Rubella infection In utero HIV infection
What abnormality causes oligohydramnios? POTTER sequence esophageal atresia anular pancreas microcephaly renal agenesis