Placenta And Fetal Membranes Flashcards
Which Cell Layer becomes the Placenta?
Trophoblast
Name the function of the Cytotrophoblast and Syncytiotrophoblast.
Cytotrophoblast: STEM CELL layer, gives rise to the Syncytiotrophoblast
Syncytiotrophoblast: Proteolytic Enzymes and hCG, Responsible for Implantation
When do you have the formation of the Amnion?
Week 2
What is the Decidua Reaction? When does it occur?
Week 2
Changes in the Endometrium: Cells of the endometrium are going to rupture, providing NUTRIENTS to the developing embryo)
Which embryonic structures will form the Umbilical Cord and the FETAL portion of the placenta?
CONNECTING STALK: Extraembryonic SOMATIC mesoderm (Umbilical Cord)
CHORION: Extraembryonic SOMATIC mesoderm (Placenta)
What are the three cells that are giving rise to the Chorion?
- Cytotrophoblast
- Syncytiotrophoblast
- Extraembryonic Somatic Mesoderm (Need to Form blood vessels)
When does Implantation occur?
2nd Week
Differentiate between the TWO types of HYDRATIDIFORM MOLES. What happens when you have this type of Mole?
Complete: Fertilization of an EMPTY OOCYTE
Partial: Fertilization of a NORMAL OOCYTE by TWO SPERM
Abnormal TROPHOBLASTIC Proliferation, excessive amounts of hCG produced
Which type of tumor can develop from a Hydatidiform mole?
Choriocarcinomas
List the Clinical features of Hydatidiform Moles.
- Looks like your pregnant (from hCG secretion)
- No Fetal Heart Beat
- Pelvic Pressure or Pain
- Enlarged Uterus
- Hyperemesis Gravidarum (Morning Sickness)
List the structures that contribute to the Fetal Part of the Placenta.
- Chorionic Sac
2. Amnion
List the structures that contribute to the Maternal Part of the Placenta.
- Decidua Basalis
- Decidua Capsularis
Part of the Endometrium
When is the amnion formed? What is the composition and function of the amniotic fluid?
- Week 2
- Composition: Steroid hormones, ions and small molecules, Glycophospholipids
- Functions: Cushions against Injury, maintains Temperature, ease of Movement, and Diagnostic Information
List the sources of Amniotic Fluid.
- Amnion (Early on)
- Maternal Blood
- Fetal Urine (starts around week 11)
What is Oligohydramnios and what is a cause?
- LOW Volume of Amniotic Fluid
- RENAL AGENESIS: you are not going to get Fetal Urine (One of the primary source of amniotic fluid)
What is Polyhydramnios and what are some causes?
- HIGH volume of Amniotic Fluid
- Causes: Ancencephaly (no brain, can’t swallow), Esophageal Atresia (block swallowing), Maternal Diabetes, Twins, and Hypoplastic Lungs
Explain Amniotic Band Syndrome.
Bands are formed and they can wrap around different parts of the embryo. (What happened to Gabi)
Explain the structures the are associated with the Primary Chorionic Villi. When do they form?
- Cytotrophoblast (Grows towards the endometrium)
- Syncytiotrophoblast
- Trophoblastic Lacuna (Spaces that have blood from mom)
DAYS 13-14
Explain the structures that are associated with the Secondary Chorionic Villi. When do they form?
- Extraembryonic Mesoderm
- Cytotrophoblast
- Cytotrophoblastic SHELL is the interface between Maternal and Fetal Placenta
- Syncytiotrphoblast
- Intervillous Space (Lacuna): Filled with MOM’s blood
DAYS 15-18
Explain the structures that are associated with the Tertiary Chorionic Villi. When do they form?
- Villous Capillaries
- Extarembryonic Mesoderm (Differentiates into FETAL VESSELS where you get GAS exchange!)
- Cytotrophoblast
- Syncytiotrophoblast
- Intervillous Space (Lacuna)
- Main STEM Villus (Branches off of chorionic plate)
- Anchoring Villus (Anchors villous to Cytotrophoblastic Shell)
- Branching Villus
Differentiate between Decidua Basalis, Decidua Capsularis and Parietalis.
Decidua Basalis: Part of the Decidua DEEP to where the embryo implants
Decidua Capsularis: Superficial part of the Decidua overlying where the embryo implanted
Decidua Parietalis: Remaining parts of the Decidua (Endometrium)
Explain the Gestational changes that are going to happen within the different layers of the Decidua (Endometrium).
- Amnion and Chorion will fuse (Forms the AMNIOCHORIONIC MEMBRANE)
- Villi next to the Decidua Capularis are going to be compressed, die and turn into Smooth Chorion (Chorion Laeve)
- Fusion of Decidua Capsularis and Parietalis
- Smooth Chorion then fuses with the Decidua Parietalis
- Fetus is going to take up most of the space of the Uterus now!
Which villus is right next to the Cytotrophoblastic Shell?
Anchoring Villi
Name the structures that are associated with the Maternal and Fetal Sides of the Placenta?
Maternal Side
- COTYLEDON
- Made of 1-2 Main Stem Villi Branches and Placental Septum
FETAL Side
- Umbilical Cord
- Amnion
Differentiate between Placenta Accreta, Placenta Increta, and Placenta Percreta.
Placenta Accreta: Abnormal adherence of Chorionic Villi to MYOMETRIUM
Placenta Increta: Chorionic Villi will PENETRATE INTO the myometrium
Placenta Percreta: Chorionic Villi will Penetrate into the Myometrium to UTERINE SEROSA or ADJACENT ORGANS
Explain Placenta Previa.
- Vaginal Bleeding beyond 20 weeks gestation
- Do NOT do a digital vaginal exam if you see bleeding because you can cause rupture of the placenta
- COMPLETE Placenta Previa is when you have the placenta covering the entire Internal Uterine Os
What are some structures that are NOT able to cross the placenta?
- Hormones (Insulin or Pituitary Hormones)
- Antibodies (IgD, IgM, and IgE)
- Heparin
- Bacteria in general
Explain how Rh Hemolytic Disease develops.
Rh-Positive FATHER
Rh-Negative MOTHER
Baby #1 is going to be fine (Mom made anti-bodies against Rh-Positive Ags)
Mom’s IgGs against Rh-Positive Ags can cross the placenta barrier and attack the babies blood cells!
Mild to Severe
Explain the function, derivative and location of the Allantois.
- Posterior to midline
- Endoderm
- PROVIDES a TEMPLATE for the Umbilical Arteries and Vein
- Becomes URACHUS
List the structures that are part of the Umbilical Cord.
- Amnion (COVERS umbilical cord)
- Extraembryonic Mesdoderm (Wharton’s Jelly; good source of stem cells)
- Umbilical Arteries (2, Oxygen Poor)
- Umbilical Vein (1, Oxygen-RICH)
- Vitello-intestinal Duct (Important for when the Gut Herniates out of the body)
What are some Clinical Problems that are seen with the Umbilical Cord?
True Umbilical Cord Knot
Absence of Umbilical Artery
- May be associated with chromosomal and fetal abnormalities
Differentiate between Monozygotic (Before Trophoblast, Week 1, Week 2) and Dizygotic Twins.
Before Trophoblast: 2 Placentas, 2 Chorions, 2 Amnions
Week 1: 1 Placenta, 1 Chorions, 2 Amnions
Week 2. 1 Placenta, 1 Chorions, 1 Amnion
Dizygotic: 2 Placenta, 2 Chorions, 2 Amnions, Can be male AND female
MONOzygotic: Will be the SAME sex
