Placenta Flashcards
(44 cards)
What cells of the blastocyst attach to the endometrial lining?
Trophblasts bind to the endometrial lining and invade the tissue to implant the blastocyst
What are the layers of the placenta?
- *Amnion**
- *Chorion**
- *Decidua** - bascially the endometrium of the uterus. Provides a barrier between chorion and myometrium.
Deoxygenated is carried in the ___________ while oxygenated blood is carried in the ___________.
Deoxygenated is carried in the umbilical artery while oxygenated blood is carried in the umbilical vein.
What structures make up the chorionic villus?
• compare the appearance of the chorionic villus at 10 weeks to the villus near term.
Villus Structure:
Outer Layer - Synciotrophoblasts
Inner Layer - Cytotrophoblasts
Within the Villus:
- *Fetal Blood Vessels**
- *Hofbauer** bodies (macrophages)
• In the course of pregnancy the Synciotrophoblasts on the outside of the villi become increasingly nodular and the overall thickness of the villus is reduced .
________ and _________ are two genes found in _________ and ____________ that regulate placental development.
HLX and DLX3 are two genes found in Trophoblasts and Blood Vessels that regulate placental development.
What is the intervillus space?
• How does this show up histologically?
Intervillus space • **Maternal Blood is Dumped here** so that nutrients can diffuse across the chorionic villi (remember synciotrophoblasts don't have MHC class I)
Histologically the intervillus space shows up as white empty space surrounding the Cellular (fetal) blood filled Villus
Blood from _________ enters the Intervillus space to exchange nutrients.
Endometrial Spiral Arteries
What happens to the allantois at weeks 5-7 of development?
The Allantois becomes the Urachus
Allantois - connects umbilicus directly to urogenital sinus
Urachus - connects umbilicus to the bladder
What should you see in a cross-section of the umbilical cord?
Allantois (possibly)
Placental Vein
Whartons Jelly
2 Placental Arteries
****NL has 3 BVs total***
Symmetric Growth Restrictions
• What is it?
• What causes it?
What is it?
- All organ systems are equally affected
Causes:
- *- Chromosomal Disorders
- Congenital Abnormalities
- Congenital TORCH infections
- Conditions that decrease fetal blood flow**(pre-eclampsia, chronic HTN)
What is the most common cause of a 1st trimester spontaneous abortion?
Chromosomal Abnormalities
What are 3 common factors that lead to 2nd trimester fetal loss?
- *1. Maternal Endocrine Factors
2. Fetal Physical Defects
3. Infection**
What infection might you contract from eating deli meat that can be extremely harmful to the fetus?
Listeria can penetrate the Placental Barrier much like it can cross the BBB
What paremeters define a spontaneous abortion?
Fetal Loss Before 20 weeks
Listeria can cause both necrotizing intervillositis and chorioamnioitis.
• Which of these is a maternal and which is a fetal inflammatory response.
These are probably both maternal inflammatory responses
What are two inflammatory processes that may occur in the umbilical cord?
• are these maternal or fetal responses?
FETAL immune system is responsible for Vasculitis (Phlebitis and Arteritis) and Funisitis in the umbilical cord
What two types of funisitis are seen in the umbilical cord?
• What do these look like?
Necrotizing Funisitis - long standing inflammation and cellular debris
Peripheral Funisitis - found at the periphery of the umbilical cord (in wharto
What is the most common cause of acute chorioamnionitis with peripheral funisitis?
• What is the implication of this infection?
CANDIDA ALBICANS
• Often this occurs leading to Pre-Term Deliveries
What Gross and Microscopical findings would you expect to see on an umbilical cord affected by acute chorioamnionitis and peripheral funisitis?
Gross:
• Well Circumscribed yellow plaques on the umbilical cord
Micro:
• Microabscesses with yeast in wharton’s jelly
CMV
• What inflammatory Process does it cause?
• What do you expect to see histologically?
• Gross?
CMV causes Chronic Villitis
Histo:
Lymphocytic/PLASMOCYTIC villi with inclusion bodies
Hofbauer body (macrophage) Hyperplasia
Gross:
Placenta may be large and edematous or small and fibrotic
Parvovirus B19
• Name of Disease Caused
• Pathophysiology
• Histology
Disease Caused
• Erythemia Infectiosum
Pathophysiology
• Destroys early RBCs (normoblasts) causing anemia and hydrops fetalis
• MYOCARDITIS in the fetus is also a potential outcome
Histology:
• Eosinophilic Nuclear inclusion in Erythroid Precursors in villi
• Viral inclusions in erythroblast precursors
Twin-Twin Transfusion Syndrome
• Pathophysiology
In Monochorionic twins vascular anastomoses exist between the circulations of the 2 fetuses some of these form AV shunts that favor shunting to one twin over the other
This leads to one big erythematous recipient twin and one small anemic donor twin at birth (if they both make it to term)
What structure is lacking in placenta accreta?
• what complications are associated with this pathology?
Abscence of a Decidua is what allows for the placental tissue to attach to the myometrium
Placenta accreta may lead to massive hemorrhage in delivery
Note: In Abruptio Placenta there is often a RETROPLACENTAL blood clot that forms