Placenta produce very important hormones. These hormones are…
White jelly like tissue( Walton’s jelly) coved umbilical vein and artery.This is protect of umbilical cord and promotion of blood flow.
I’m going to talk about fetal growth and development.This is 8week old fetus. Fetus look like human but mother don’t know she is pregnant or not.She missed just one period(menses), may be she doubt why is not start menstruation.But this period is very important. If mother takes any medicines or drugs or get disease, fetus has influenced these hazard. Therefore fetus get some kind of anomalies.
40 weeks is from onset of last menstrual period.If delivery not occur over 40weeks over, baby gets distress condition, because placenta can not sufficient oxygen and nutrient.