Module 9 : Normal Fetal Anatomy - Placenta and Cord Flashcards
1
Q
at what week do we see two distinct components o the placenta
A
12 weeks
2
Q
two distinct components of the placenta
A
chorion frondosum
decidua basalis
3
Q
chorion frondosum
A
fetal portion
4
Q
decidua basalis
A
maternal portion
5
Q
how are the two layers held together
A
- anchoring or stem villi at the cytotrophoblastic shell
6
Q
intervilluous spaces
A
- syncytiotrophoblast cells create large spaces in the decidua basalis
7
Q
placental septa
A
- remaining projections of the decidua basalts
- septa divide the placenta into compartments
8
Q
cotyledon
A
- each compartment the septa divide into in the placenta
- consist of several stem villi
- about twenty in a placenta
9
Q
placenta membrane
A
- separates the fetal blood in the capillaries of the CHORIONIC VILLI from the maternal blood in the INTERVILLOUS SPACES
- maternal blood enters the intervillous spaces via the spiral arterioles
10
Q
maternal circualtion
A
- spiral arterioles shoot blood around the chorionic villi
11
Q
fetal circulation
A
- from umbilical arteries to chorionic villi back to umbilical veins to baby
12
Q
functions of the placenta
A
- respiration (exchange oxygen)
- nutrition
- excretion (carbon dioxide)
- protection (toxic elements)
- storage
- hormonal production
13
Q
sonographic appearance
A
- early = homogenous
- venous lakes along the basal plate and in the septa
- may see calcifications later in pregnancy due to maternal serum calcium levels
14
Q
grading of placenta
A
- grade 0 - 3
15
Q
grade 0 placenta
A
- homogenous
- chorionic plate is straight