How does fetal hemoglobin enchance oxygen transfer across the placenta from the mother to the fetus?
825900
Both mother and fetus share a common blood supply. In particular, the fetus's blood supply is delivered via the umbilical vein from the placenta, which is anchored to the wall of the mother's uterus. As blood courses through the mother, oxygen is delivered to capillary beds for gas exchange, and by the time blood reaches the capillaries of the placenta, its oxygen saturation has decreased considerably. In order to recover enough oxygen to sustain itself, the fetus must be able to bind oxygen with a greater affinity than the mother.\n\nFetal hemoglobin's affinity for oxygen is substantially greater than that of adult hemoglobin. Notably, the P50 value for fetal hemoglobin (i.e., the partial pressure of oxygen at which the protein is 50% saturated; lower values indicate greater affinity) is roughly 19 mmHg, whereas adult hemoglobin has a value of approximately 26.8 mmHg. As a result, the so-called "oxygen saturation curve", which plots percent saturation vs. pO2, is left-shifted for fetal hemoglobin in comparison to the same curve in adult hemoglobin.\n\nThis greater affininty for oxygen is explained by fetal hemoglobin's interaction with 2,3-bisphosphoglycerate (2,3-BPG). In adult red blood cells, this substance decreases the affinity of hemoglobin for oxygen. It is also present in fetal red blood cells, but does not interact with fetal hemoglobin, leaving its affinity for oxygen unchanged. Adult hemoglobin alone actually has a higher affinity for oxygen than its fetal equivalent, but the levels of 2,3-BPG reduce it.
916179
oxygen helps in breathing of the million cells in your body.Blood transfers oxygen to the cells & the cells can carry out their processes with help of oxygen.Since everything requires energy to carry on its processes,human require oxygen to carry out its process of living
797207
A gas moves from a high pressure to a low pressure. When you breathe in, the partial pressure of oxygen in the lungs is higher than in the blood. Therefore the oxygen will move from the lungs to the blood. The exact opposite is true for carbon dioxide.
924561
The baby makes its own blood. It comes neither from the father or the mother. While it is in the womb, its own blood circulates through the cord and receives nutrients from the mother but the baby's blood and the mother's are separate and never normally mix. \n\nSince the baby receives genes from both the mother and the father, the type of blood is influenced by that.
594197
The maternal and fetal circulatory systems only come in contact at one place--the placenta.  The mother's antigen-presenting cells can't cross the placenta, so if an immune response was going to be mounted it would be there.  Two basic ideas as to why this doesn't happen:\n\n(1) The trophoblasts that form the fetal half of the placenta don't express the usual major histocompatibility complexes that would ordinarily prompt immunological responses in adult tissues (for example, in transplant grafts).  In other words, the fetal half of the placenta is invisible to the mother's T-cells.\n\n(2) The trophoblasts that form the fetal half of the placenta produce cell surface proteins that actively suppress the mother's immune response in the vicinity of the placenta.\n\nFor a very recent (published March 2006), in-depth review, see my source....
619312
it goes into your lungs and then straight into your blood stream from there.  how do you think oxygen gets in your blood??
1095196
Deoxygenated blood enters the right atrium of your heart which delivers the blood to you right ventricle.  The right ventricle pumps blood to your lungs where the carbon dioxide is dumped for exhalation and the oxygen is loaded onto the hemoglobin molecules in the blood.  Then the oxygenated blood is delivered to your left atrium which then fills your left ventricle.  The muscles in the walls of your left ventricle are thick because they pump blood out of your heart, through your aorta and to the rest of your body - a very big job!
382129
NO, it's not the placenta.  It's the amnionic sac that surrounds newborn mammals.  Kittens and puppies have them as well, and so do humans, but human infants loose them before they are born.  \n\nIf you watch kittens or puppies being born the mother will lick the sac away and the licking stimulates breathing in the pup or kitten.
503138
As far as I know, no.\n\nHowever, it is necessary for a pregnant woman to keep her haemoglobin level ok, because if not, she will have anemia and she can't provide her baby with enough oxygen.\n\nCalcium is necessary too, so that bones of the baby form well.
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It doesn't turn red when it is exposed to oxygen.  It is red.  What you see through your skin is the color of the veins.\n\n\nIt turns out that hemoglobin has a red color to\nit and that oxygenated hemoglobin is bright red.  So in arteries blood\nappears to be bright red.  This is true inside and outside.  Outside of the\nbody the color actually fades a bit (becomes darker), because there is less\npressure to keep oxygen associated with the hemoglobin.  But if you cut an\nartery the blood squirting out will appear bright red.  Blood that is in\nveins, however, has very little oxygen associated with it and this yields a\ncolor that is much darker.  As you noted, because of having to look through\nthe skin at veins they actually take on a blue tint, but really the blood\ninside (and if you cut a vein) is just a deep shade of red.  You can also\nsee this in persons that have stopped breathing or have blood flow blocked\nto a specific area; they appear blue. (A condition referred to as cyanosis.)
136104
The umbilical cord is attached to the placenta. The placenta sends oxygen and absorbs nutrients to send to the baby through the umbilical cord.
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it happens , the partial perassure of o2 is less in cells than in hemaglobin so it diffusses in to cells frm hemoglbin
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Two veins which carry oxygenated blood from the mother to the baby and one artery which carries the deoxygenated blood away from the baby.  In between these vessels is Wharton's jelly which keeps the vessels from collapsing
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The unborn fetus is completely dependent on the mother for all vital functions. The oxygen and nutrients ALL come from the umbilical cord by way of the placenta. Their is no oxygen in amniotic fluid for the baby.. The lungs are not inflated in the unborn fetus and although it may swallow amniotic fluid while in utero, it does not enter the lungs. The circulatory system is adapted to life within the uterus. Little blood flows through the pulmonary artery because of natural openings in the heart that close at birth or shortly after. When the umbilical cord is clamped, the lungs take on the function of breathing oxygen and removing carbon dioxide. The first breath helps to expand the collapsed lung but full expansion may take several days. Sometimes during birth a baby may aspirate some amniotic fluid it has swallowed into its lungs, usually not a problem unless the baby has passed meconium during labor .
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Higher partial pressure of O2 in atmosphere that that present in the blood.\n\nRemember, blood in the lungs will be DEOXYGENATED!
118751
its where the blood picks up the oxygen.
643625
The transfer of oxygen occurs in the tiny capillaries.  The walls of capillaries are very thin and allow close proximity to the cells in need of oxygen.  The reason that oxygen passes through, is that it is moving from a high concentration of oxygen (in the capillaries) to a low concentration of oxygen (in the cells).