The placenta is the primary site of ___ and ___ exchange between the fetal and maternal circulations.
decidua parietalis, decidua vera
What is the decidualized endometrium along the remainder of the inner surface of the uterus called?
chorionic villi, sinusoidal spaces
Chorionic tissue forms ___ ___ which interact with the maternal decidua to form a network of ___ ___.
What allows close approximation of fetal and maternal circulations for passage of nutrients and oxygen?
8, chorion laeve, smooth chorion
After __ weeks, the villi along the surface of the gestational sac opposite the implantation site become compressed as the sac grows. Degeneration of these villi forms the ___ ___, also known as the ___ ___.
The chorion at the base of the implantation site rapidly proliferates, forming the ___ ___.
As the pregnancy progresses, the chorionic villi branch and gradually develop into a complex system of __-__ subunits or lobules.
The fetal surface of the placenta is termed the ___ ___ and is continuous with the surrounding chorion.
the structure that attaches a developing fetus to the uterus and that enables the exchange of nutrients, wastes, and gases between the mother and the fetus
The maternal surface of the placenta, which is continuous with the decidua basalis, is termed the ___ ___.
left ventricle, ductus arteriosus
Fetal-umbilical circultaion originates with deoxygenated blood pumped by the ___ ___ of the fetal heart, through the ___ ___, and into the descending aorta.
hypogastric arteries, umbilical cord
Fetal blood continues through the ___ ___ to the umbilical arteries and into the ___ ___.
Within the placenta, the ___ ___ freely divide into multiple capillary branches that course through the villi.
spiral arteries, uterine arteries
Oxygenated maternal blood is delivered to the placenta through the ___ ___ which are branches of the ___ ___.
Maternal blood enters the ___ ___, where it flows around and over the chorionic villi.
The process of placental circulation permits exchange of oxygen and nutrients with fetal blood in the ___ ___.
The early ___ ___ appears as an area of appearent thickening in the decidualized endometrium.
The placental location is usually in the ___ to ___ portion of the uterus, reflecting the site of implantation.
bladder, fibroids, contractions
Apparent location of the placenta can change markedly with distension of the ___, ___ and ___.
The ___ ___ can be recognized on sagittal scans as an echogenic line surrounded by a hypoechoic zone of variable thickness.
Calcium deposition in the placenta normally occurs as the placental grade increases which is usually in the ___ trimester.
Calcium may be deposited along the ___ ___ of the placenta and along the septa separating the placental lobes.
___ ___ results from a lack of formation of a normal decidual plate. The chorionic villi extend into the myometrium and the placenta cannot separate normally following delivery. Hemrrhage can result.
___ ___ results from premature separation of the placenta prior to delivery with formation of a retroplacental blood clot. The blood supply to the fetus is compromised.
A numerical grade is assigned to the placenta based on the appearance of ___ within the placenta.
A grade ___ is given to a placenta with calcification of the basilar plate with comma-like echogenicities extending into the placenta from indentations of the chorionic plate.
A grade ___ is given to a placenta with extensive basal echogenicities and the curvilinear echogenicities extending from the chorionic plate reach the basal plate.
The measurement of the placenta should be taken in the ___ of the placenta and should be perpendicular to it. It should measure less than ___.
maternal diabetes, Rh sensitization, feto-maternal hemorrhage, chronic intrauterine infection, TTTS, chromosomal abnormalities, fetal hydrops
What are some causes of placentomegaly?
IUGR, intrauterine infection, chromosomal abnormalities
What can cause an abnormally small placenta?
A thin layer of placenta covering nearly the entire surface of the uterine cavity
Development of placental tissue separate from the main body of the placenta; accessory placenta
anomaly in which the chorionic plate of the placenta is smaller than the basal plate
when the interface between the placenta and the fetal membranes remain flat
What involves the infolding of fetal membranes and placenta on the fetal surface.
painless vaginal bleeding during the 2nd or 3rd trimester
What is often the symptom for placenta previa?
when the placenta is in the lower uterine segment but is not touching or on the edge of the internal os
abnormal adherence of the placenta to the uterine wall; there is complete or partial absence of the decidua basalis; the chorionic villi adhere directly into the myometrium
placenta accreta is more common in ___ females, especially those with a Hx of previous ___.
the normal placenta separates from the underlying myometrium prematurely. usually associated with severe pain and vaginal bleeding.
pathology that separates the basal plate of the placenta from the uterine wall
seen at the periphery of the placenta, commonly elevating the edge of the placenta
the presence of a hematoma may result in placenta ___ by separation of the chorionic villi from the maternal blood vessels.
If a hematoma involves __-__% of the maternal surface, there will likely be siginificant hypoxia to the fetus.
The cause of bleeding for a hematoma is not usually known but is usually associated with ___.
the ___ ___ serves as aconduit for oxygen and nutrients between the mother and fetus.
The ___ ___ may be counted at the cord insertion into the fetus towards the bladder.
marginal insertion, battledore placenta
Eccentric umbilical cord insertion is common and not clinically significant. this is known as ___ ___ or a ___ ___.
focal umbilical cord masses are uncommon and are usually localized deposits of ___ ___.
a cystic mass of the umbilical cord may represent a ___ ___. it will normally resolve before birth and has been associated with an omphalocele.