Fetus-maternal and placental circulation
Abdulrahman Shah 1/11/18
Describe the feto – placental and maternoplacental circulation.
Before discussing feto-placental and maternoplacental circulation, let me discuss what placenta is and what placental circulation confers to
The placenta is an organ that facilitates transport/a gateway of nutrients gases, synthesizes necessary hormones and influences metabolism. it is a feto-maternal organ. Placental circulation refers to the movement/exchange of substances between the mother and the fetus.
Fetal-placental circulation: basically refers to the movement from fetus to mother, and includes movement of deoxygenated blood or poorly oxygenated blood and wastes back to the mother. The mechanism of how this takes place includes.
the placenta connected formed of two umbilical arteries and one umbilical vein located in the umbilical cord, the fetus transfers poorly oxygenated blood through the umbilical arteries back to the mother by then entering -> umbilical arterioles-> fetal capillaries in the chorionic villi in the placenta
the wastes enter the intervillous space-> maternal decidua capillaries->spiral venules->spiral veins-> into maternal circulation, the wastes include urea, uric acid and bilirubin.
Maternoplacental circulation: this includes movement of highly nutritious and well oxygenated blood from the mother to the fetus.
The oxygen rich blood and nutritious blood enter Through the spiral arteries in the decidua basalis(maternal part) into the intervillus fetal capillaries in the branch chorionic villi and then into umbilical vein. Fetal blood is separated from the maternal blood by the placental membrane
2. Trace the flow of blood in the fetal circulation, and state the function of foramen ovale and ductus arteriosus.
The blood enters in the umbilical vein through the intervillous space and then the red blood that enters the fetus passes through the fetal liver and enters the right side of the heart. The blood that is traveling goes through 2 major gateways or connections that will close after birth. One of them is the is the foramen ovale which is located between the right and left atrium. Permit blood to go to right then to the left atrium which then, makes its way into the left ventricle and into the aorta and finally to the brain that receives blood with most oxygen.
The deoxygenated blood makes it back into the right atrium -> right ventricle-> blood that leaves the right ventricle in the fetus bypasses the lungs.
Ductus arteriosus sends the bluer blood to the organs in the lower half of the fetal body, through the umbilical arteries and get back to the placenta to pick up oxygen.
3. Explain where the foramen ovale and ductus arteriosus are located, and describe their purpose
foramen ovale is described as a “door” between the right and left atria that is essential for proper fetal circulation, directing oxygenated, to the brain.
ductus arteriosus, connects the pulmonary artery to the proximal descending aorta and this allows most of the blood from the right ventricle to skip through the fluid-filled non-functioning lungs.