2006-06-20 06:01:03 · 6 answers · asked by cobalt_lover 1 in Pregnancy & Parenting ➔ Pregnancy
Human fetuses don't "breathe" the amniotic fluid surrounding them in the womb. The function of the fluid, among other things, is to act as a shock absorber.
Inside the womb, the lungs are non-functional and are among the last organs to develop. Because the lungs are non-functional, blood does not need to travel there for gas exchange and fetal circulation is slightly different than in adults. There are two structures in the heart (foramen ovale and ductis arteriosis) that divert the flow of blood so that it mostly bypasses the lungs. Oxygen and nutrients from the mother come to the fetus through the umbilical vein leading from the placenta through the umbilical cord to the inferior vena cava in the abdominal cavity. The umbilical artery carries most metabolic wastes from the fetus back to the placenta.
At birth, the lungs begin to function as the primary site for gas exchange and the physical link between the mother and fetus is broken when the placenta is expelled (i.e. afterbirth) and/or when the umbilical cord is cut, whichever comes first.
2006-06-20 06:04:27 · answer #1 · answered by sciguy 2 · 1⤊ 0⤋
We don't inhale the fluid.. The precursor cells of the human placenta and the trophoblasts first appear four days after fertilization and they differentiate into all the other cell types found in the human placenta. When fully developed, the placenta serves as the interface between the mother and the developing fetus. The placenta is critical for a successful pregnancy by mediating such critical steps as implantation, pregnancy hormone production, immune protection of the fetus, increase in maternal vascular blood flow into it, and delivery. Over the next few weeks the placenta begins to make hormones which control the basic physiology of the mother in such a way that the fetus is supplied with the necessary nutrients and oxygen needed for successful growth.
A fetus doesn't breathe because it's encased in an embryonic "sac". The fetus recieves the oxygen and nurtients through the placenta. We take our first breath at birth.
2006-06-20 06:08:11 · answer #2 · answered by Alley S. 6 · 0⤊ 0⤋
Because our lungs are used to the fluid in the womb, they are not prepared or ready to breathe air. The lungs practice "breathing" by taking in the fluid in the womb. The reason babies are either blue or gray and then let a big cry when born is because the lungs have no oxygen in them. Once the baby gets a breath of air, the color comes in and the baby lets out a cry.
2006-06-20 06:07:04 · answer #3 · answered by ambullmom 2 · 0⤊ 0⤋
There is some fetal muscle movement of the thorax and diaphragm, but not constant rhythmic "breathing". And of course there is no oxygen exchange there. Actually the alveoli or air sacs are collapsed until those first few breaths after birth. Oxygen is supplied to the fetus via the umbilical vein (yes, the vein!) from the placenta.
2016-03-26 22:52:44 · answer #4 · answered by Anonymous · 0⤊ 0⤋
We have gill like undeveloped lungs when we are in the womb.
2006-06-20 06:13:46 · answer #5 · answered by eehco 6 · 0⤊ 0⤋
mother nature.
Amazing. Isn't it?
2006-06-20 06:18:31 · answer #6 · answered by Anonymous · 0⤊ 0⤋