1619_mj-decidua, chorion, placenta, umbilical cord
DESCRIPTION
placentaTRANSCRIPT
Decidua, chorion, placenta, umbilical cord.
Doc. MUDr. Marie Jirkovská, CSc.
Institute of Histology and Embryology
1
Deciduaendometrium in pregnancy- decidua basalis - pars materna placentae
(endometrium)
schema
secretory phase
decidual cells
Chorion
B.M.Carlson: Human Embryology and Developmental Biology, 1999
Decidua basalis
Chorionic villi primary (P) secondary (S) tertiary (T)
P
PS
syncytiotrophoblast
cytotrophoblast
capillary
Hofbauer‘s cells
ChorionS - syncytiotrophoblast, C - cytotrophoblast, M - mesenchyme,
H - Hofbauer cells
H
M
C
S
Chorionic villi *proliferation and migration of cytotrophoblast, C – cytotrophoblast shell, V – chorionic villus, D - decidua
*
*
V
V
CC
D
Relationship of decidua and chorion
Human placenta at termDiscoid (diameter 15 – 20 cm, thickness 2 – 3 cm) – according shapeHemochorial villous – according structure Placenta consists of: fetal part (villous chorion) and maternal part (decidua basalis)
cotyledons
Human placenta at term – a scheme
Fetal part: chorionic plate and cotyledons consisting of one or more main stem villi and their branches.Maternal part: decidual plate is covered by syncytiotrophoblast, contains decidual cells and remnants of the cytotrophoblastic shell.
Placenta at low magnification
Stem and intermediate villi
Fibrinoid – eosinophilic mass on the surface of villi, decidua basalis and chorionic plate (material composed of fibrin from maternal blood and degenerated cells).
Placenta
Terminal villi Placental septum
syncytiotrophoblast
vasculosyncytial membrane
cytotrophoblast decidual cell
capillary
3-D reconstruction of the villous capillary bed
1
Umbilical cordlength cca 50 cm
A – a. umbilicalis, V – v. umbilicalis, E – ectoderm of the amnion, W – Wharton‘s jelly
VA
W
E
E
W
A
V