section_heading: Krvni tlak
paragraph_text: Krvni tlak opada kada krv protječe kroz posteljicu. U pupčanoj arteriji mu je vrijednost 50 mmHg.<ref>Fetal and maternal blood circulation systems From Online course in embryology for medicine students. Universities of Fribourg, Lausanne and Bern (Switzerland). Retrieved on 6 April 2009 Pada na 30 mmHg u kapilarama korionskih resica. Zatim, tlak pupčane vene je 20 mmHg u trenutku kad se krv vraća prema srcu.<ref>