Page 68 - كتاب تمريض نسا الاكتروني

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-Spaces appear in synthetiotrophoblast, then these spaces fuse together to form chorion-

decidual space

-Erosion off maternal blood vessels by trophoblast allow blood to flow in this space

-The placenta grows throughout pregnancy. Development of the placenta is complete -

. by the end of the first trimester of pregnancy week

Maternal Placental circulation

-In preparation for implantation of the blastocyst, the endometrium undergoes

decidualization.

Decidua: is the endometrium of pregnancy.

The decidua has three regions:

1-Decidua Basalis: is that part of the decidua deep to the embryo, and adjacent to

chorion frondosum. It will form the maternal part of the placenta .

2-Decidua capsularis: is that part of the decidua, which lies superficial to the embryo

and covers it towards the uterine cavity.

3-Decidua Parietalis/ vera: is the remaining part of the endometrium .

The decidua has three features:

1-endometrium becomes thicker, and its glands are large, tortuous and their cells are

filled with mucous & glycogen.

2-Connective tissue stroma cells enlarge to form decidual cells, which contain large

amount of glycogen and lipids, which provide a source of nutrition for the developing

embryo.

3-The endometrial blood vessels become highly engorged and more spiral to increase

maternal blood flow to the placenta. They are eroded by trophoblast to pour their

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