10.5 Fetal Circulation Flashcards
why are features necessary for gas exchange diff for fetus
-dont use lungs for gas exchange
foramen ovale
shunts blood from right atrium to left atrium
ductus arteriosus
blood that does not enter right ventricle and is pumped into pulmonary trunk is shunted into aorta by ductus arteriosus
umbilical artery
O2 low blood in aorta travels to various branches connect to umbilical arteries in the placenta
umbilical vein
- enters liver and then joins ductus venosus,carries O2 blood rich in nutrients and oxygen to fetus,
ductus venosus
merges w inferior vena cava (vessel that returns blood to the heart)
umbilical cord
- tied off and cut at birth leaving only umbilicus
- lifeline of fetus contains umbilical arteries and vein which transports waste molecules in placenta for disposal and take oxygen and nutrient molecules from placenta to rest of the fetal circulatory system
describe one of the common defects in newborns
- persistence of foramen ovale
- once umbilical cord has been servered and lungs expanded, blood enters lungs in quantity. the return of blood to left side of heart causes a flap to cover opening, incomplete closure, passage of blood to left atrium from right atrium rarely occurs bc either opening too small or it closes when atria contracts
- passage of impure blood from right to left side of heart causes a blue baby lmao
how can blue baby be treated
threading catheter into heart and sealing defect
what happens to ductus arteriosus after endothelial cells divide
ductus arteriosus normally closes bc endothelial cells divide and block off this duct, remains of ductus arteriosus and parts of umbilical arteries and veins are transformed into connective tissue
what is placenta
firmly attached to uterine wall by allatois and chorionic villi
- structure that functions only before birth, becomes “afterbirth” after child born
- functions in gas, nutrient, waste exchange between embryonic (later fetal) and maternal circulatory systems
