A nurse shows an understanding of growth and development occurring in the first 3 weeks post-conception when discussing:

Question

1. How the embryo has attached to the wall of the uterus.
2. Development of the fetal membranes and the amniotic sac.
3. How the embryo will be covered with a protective substance called vernix caseosa.
4. How development of the fetal placenta has begun.
5. How the embryo is covered with a soft, downy hair.

Answer 1

Correct Answer: 1,2,4
Rationale 1: Events occurring concurrently during the first 3 weeks include the embryo's being implanted in the endometrium of the uterus.
Rationale 2: Events occurring concurrently during the first 3 weeks include fetal membranes' differentiating into the chorion—precursor to the placenta—and the amnion, precursor to the amniotic sac.
Rationale 3: At the end of the second trimester, or 6 lunar months, a protective covering called vernix caseosa begins to develop over the skin.
Rationale 4: Events occurring concurrently during the first 3 weeks include the function of the placenta.
Rationale 5: At the end of the second trimester, or 6 lunar months, lanugo—a fine downy hair—covers the body.