Question

Read the statements and select the correct option
I. The portion of decidua where the placenta is to be formed is called decidua basalis
II. The part of decidua that separates the embryo from the uterine lumen is called decidua parietal
III. The part lining the rest of the uterus cavity is called decidua parietal

A. Only I and II.
B. Only I and III.
C. I, II and III
D. Only III

Answer 1

The decidua basalis is responsible for forming the maternal component. They are present below the conceptus. The compact layer of decidua basalis is known as the decidual plate. Another portion known as the decidua parietalis is found in the uterine mucosa.

Complete answer:
Decidua as the name suggests means “falling off” that is deciduous. The decidua is also known as the modified endometrium. During the pregnancy, it refers to the lining of the uterus. The maternal portion of the placenta is formed by this decidua. It forms as a part of conception thereby preparing the body of the female for the pregnancy. This maternal portion that is present in the placenta is known as the decidua basalis. The Villous chorion is the part of foetus present in the placenta and the remaining portion of the uterus is lined by the decidua parietalis.
On the other hand, decidua capsularis refers to the portion of decidua that parts the embryo from the lumen of the uterus.

Therefore, the correct answer is option “B” that is statement I and III are correct.

Note:
It is the altered lining of mucosa present in the uterus. Decidualization is the process which leads to the formation of this decidua. It occurs under the stimulus of progesterone hormone. In this case, the cells of endometrium become highly characterized. As the decidua refers to the maternal portion of the female placenta, it remains in the body only at the time of pregnancy. In the later stages at the birth of the child, this decidua sheds off.