Implantation and Fetal Membranes Flashcards
describe what the enzyme vesiculase does
- coagulates semen to form a plug at the externa os which prevents backflow of semen into the vagina
implantation of ____ begins on day ____ and ends on day _____
implantation of blastocyst begins on day 5/6 and ends on day 10
1 = endometrium
2 = hypoblast
- synctiotrophoblast
4 = cytotrophoblast
5 = epiblast
the usual site of implantation is….
the usual site of implantation is the posterior wall of body of uterus close to the fundus
name 2 enzymes the synctiotrophoblast secretes
- proteolytic enzymes to erode endometrium and blastocyst burrows into endometrial CT
- also secretes hCG which maintains the corpus luteum
describe pregnancy tests
- tests for hCG in maternal urine at end of 2nd week after conception
- test for presence of early pregnancy factor (EPF), an immunosuppressant protein which appears in maternal serum 24-48 hours after conception
equation for calculating expected date of delivery (EDD)
Date of last menstrual period + 9 months + 7 days (Naegele’s rule)
describe Hydatiform mole (H-mole)
- A molar pregnancy starts when an egg is fertilized, but instead of a normal, viable pregnancy resulting, the placenta develops into an abnormal mass of cysts.
- little to no embryonic tissue present
- trophoblast develops well
- hCG produced
- may give rise to choriocarcinoma
describe the primary yolk sac or exocoelomic cavity
- first site of blood formation
- gives rise to the primordial gut
- primordial germ cells arise in the endodermal lining of the yolk sac
describe the allantois
- arises as a diverticulum from the yolk sac and extends into the body stalk
- another early site of blood formation
- its blood vessels form the umbilical arteries and veins
- obliterates and forms the urachus (median umbilical ligament postnatally)
describe the function of aminiotic fluid
- shock absorber
- maitains constant temp
- lung development
- symmetrical growth
- antibacterial activity
the aminion fuses with ____ ____ and obliterates the _____ _____ forming the single ______ membrane
the aminion fuses with chorion wall and obliterates the chorionic cavity forming the single amniochorionic membrane
describe oligohydramnios and potential causes
- low volume of amniotic fluid
- causes:
- preterm rupture of amniochorionic membrane
- urinary system anomalies
- renal agenesis
- placental insufficiencies
- decreased blood circulation
- complications
- lung hypoplasia
- facial or limb deformities because less space to grow
describe polyhydramnios and causes
- high amniotic fluid volume
- causes:
- idiopathic
- maternal
- multiple pregnancies
- maternal diabetes
- fetal
- esophageal atresia
- meroencephaly
- anencephaly
- complications
- preterm labor and delivery