1. Decidua, chorion, placenta, umbilical cord.
Doc. MUDr. Marie Jirkovská, CSc.
Institute of Histology and Embryology

2. Decidua endometrium in pregnancy- decidua basalis - pars materna placentae
schema
secretory phase
decidual cells

3. Chorion Decidua basalis
B.M.Carlson: Human Embryology and Developmental Biology, 1999
Decidua basalis

4. Chorionic villi primary (P) secondary (S) tertiary (T)
syncytiotrophoblast
cytotrophoblast S P
capillary P
Hofbauer‘s cells

5. Chorion S - syncytiotrophoblast, C - cytotrophoblast, M - mesenchyme, H - Hofbauer cells

6. Chorionic villi *proliferation and migration of cytotrophoblast, C – cytotrophoblast shell, V – chorionic villus, D - decidua V V * C C * D

7. Relationship of decidua and chorion

8. Human placenta at term maternal part (decidua basalis) cotyledons
Discoid (diameter 15 – 20 cm, thickness 2 – 3 cm) – according shape
Hemochorial villous – according structure
Placenta consists of: fetal part (villous chorion) and
maternal part (decidua basalis)
cotyledons

9. 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.

10. Placenta at low magnification

11. 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).

12. vasculosyncytial membrane
Placenta
Terminal villi Placental septum
vasculosyncytial membrane
syncytiotrophoblast
cytotrophoblast decidual cell
capillary

13. 3-D reconstruction of the villous capillary bed

14. Umbilical cord length cca 50 cm
A – a. umbilicalis, V – v. umbilicalis, E – ectoderm of the amnion, W – Wharton‘s jelly E W V A W V A E