Since the placenta is bathed in the mother's blood, and the veins and arteries all take in blood from the blood bath, how do the veins know to take in oxygenated blood? Since the blood bath will contain both oxygenated blood(given by the mother) and deoxygenated blood (pushed away from the baby).
Did I miss something out? Or is there some explanation on how the veins know what type of blood to take in?
2007-09-19 22:36:24 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Biology
Dumpling muffin you misunderstand me. I know the placenta is attached to the uterine wall, but on the OTHER side of the placenta, I believe it is bathed in blood.
To Gribbling, you say that the placenta is bathed in oxygenated blood. But doesn't the foetus release deoxygenated blood back into the bath too?
2007-09-19 23:07:46 · update #1
Sorry I understand it now. The blood of the baby and the mother does not mix at all, but instead oxygen and nutrients are able to pass through and be taken in. (Through active transport, I assume?)
Anyway thanks to gribbling take 10 points! I'll vote yours as best answer as soon as it lets me.
2007-09-19 23:13:10 · update #2
The blood of the mother and the foetus do not mix, they just approach each other very closely. The placenta is actually part of the foetal tissue (it grows from the fertilised ova), while the blood supply in the uterine wall is (obviously) part of the mother.
The placenta is bathed in oxygenated blood from the mother's arteries (in the endometrial arteries), as all tissues in the mother's body are. The foetal blood (in the chorionic arteries), which is adjacent to the mother's blood (but separated from it) absorbs blood and nutrients from the mother's bloodstream.
The uptake of blood is made possible by the fact that adult and foetal haemoglobin are actually different in composition. Adult haemoglobin is composed of 2 alpha haemoglobin units, plus two beta haemoglobin units, while foetal haemoglobin is two beta, plus two gamma haemoglobin units. Foetal haemoglobin has a higher affinity for oxygen than adult haemoglobin, so it "steals" the oxygen from the mother's blood. After birth, the foetus stops making gamma haemoglobin, and only makes adult haemoglobin.
2007-09-19 22:47:00 · answer #1 · answered by gribbling 7 · 0⤊ 0⤋
its nothing like that at all,the placenta is like an organ in its self atached to the uterine wall ,there is no blood bath,imagine a large growth growing on your face well its like that
2007-09-19 22:41:57 · answer #2 · answered by dumplingmuffin 7 · 0⤊ 0⤋