Decidua
This article needs additional citations for verification. (June 2014) |
Decidua | |
---|---|
Identifiers | |
MeSH | D003656 |
TE | E6.0.1.4.0.0.7 |
FMA | 85538 |
Anatomical terminology |
The decidua is the modified mucosal lining of the uterus (that is, modified endometrium) that forms every month, in preparation for pregnancy. It is shed off each month when there is no fertilised egg to support.[1] The decidua is under the influence of progesterone. Endometrial cells become highly characteristic. The decidua forms the maternal part of the placenta and remains for the duration of the pregnancy. After birth the decidua is shed together with the placenta.[1]
Structure
The part of the decidua that interacts with the trophoblast is the decidua basalis (also called decidua placentalis), while the decidua capsularis grows over the embryo on the luminal side, enclosing it into the endometrium. The remainder of the decidua is termed the decidua parietalis or decidua vera, and it will fuse with the decidua capsularis by the fourth month of gestation.
Three morphologically distinct layers of the decidua basalis can then be described:
- Compact outer layer (stratum compactum)
- Intermediate layer (stratum spongiosum)
- Boundary layer adjacent to the myometrium (stratum basalis)
Within the decidua, occasional fibrinoid deposits form where the syncytiotrophoblast is damaged. The region of fibrinoid deposition where trophoblasts meet the compact portion of the decidua basalis is called Rohr's layer, while the fibrinoid deposits that occur between the compact and spongy layer of the decidua basalis is termed Nitabuch's layer (for
The decidua has a histologically-distinct appearance, displaying large polygonal decidual cells in the stroma. These are enlarged endometrial stromal cells, which resemble epithelium (and are referred to as "epithelioid").
Decidualization includes the process of differentiation of the spindle-shape stromal fibroblasts into the plump secretory decidual cells, which create a pericellular extracellular matrix rich in fibronectin and laminin (similar to epithelial cells).
Vascularity, as well as vascular permeability, is enhanced in the decidualizing endometrium.
Its
The large granular lymphocytes (CD56 bright) are called uterine natural killer cells| (uNK cells).
Development
After
In animals exhibiting
The decidua is shed with the placenta during birth.
Function
As the maternal interface to the embryo the decidua participates in the exchanges of nutrition, gas, and waste with the gestation. It also protects the pregnancy from the maternal immune system. Further, the decidua has to allow a very controlled invasion of the trophoblast.
In invasive placental disorders like
Hormone production
The decidua secretes
Among its products are hormones commonly associated with other organs such as
control.Other factors released include
Other
- In case of an ectopic pregnancy, the endometrium nevertheless becomes decidualized. A woman may shed the lining in the form of a decidual cast, which may be mistaken as a miscarriage, when, in fact, the ectopic pregnancy still persists.
- A stromal tissue to progesterone.
- Decidua in a lymph node may mimic metastatic carcinoma.[3]
Clinical significance
A long-lasting infection of the decidua, chronic deciduitis, is associated with pre-term labour.[4]
-
Acute choriodeciduitis, with neutrophils seen in the chorion and decidua.
History
The word comes from
Additional images
-
Scheme of placental circulation.
-
Gross pathology of fetal membranes versus decidua
References
- ^ a b "Definition of DECIDUA". www.merriam-webster.com. Retrieved 25 October 2022.
- ISBN 9780071413152.
- PMID 15859655.
- S2CID 25693917.
External links
- Histologic picture at med.utah.edu
- Histology image: 19904loa – Histology Learning System at Boston University