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In placental mammals, the umbilical cord (also called the navel string, [1] birth cord or funiculus umbilicalis) is a conduit between the developing embryo or fetus and the placenta. During prenatal development , the umbilical cord is physiologically and genetically part of the fetus and (in humans) normally contains two arteries (the umbilical ...
The amniotic membrane and its contents form the umbilical cord that connects the embryo and the placenta. [3] [4] The root of the connecting stalk contains the allantois as a diverticulum of hindgut endoderm along with umbilical vessels. [5] [2] Anomalies are usually referred to as body stalk anomalies and occur in approximately 1 in 15,000 ...
The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the fetal circulation and postnatal circulation is that the lungs are not used during the fetal stage resulting in the presence of shunts to move oxygenated blood and ...
The placenta (pl.: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation.It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate maternal and fetal circulations, and is an important endocrine organ, producing hormones that regulate both maternal and fetal ...
The embryo is joined to the trophoblastic shell by a narrow connecting stalk that develops into the umbilical cord to attach the placenta to the embryo. [11] [15] Arteries in the decidua are remodelled to increase the maternal blood flow into the intervillous spaces of the placenta, allowing gas exchange and the transfer of nutrients to the ...
The amniotic sac and its filling provide a liquid that surrounds and cushions the fetus. It is a site of exchange of essential substances, such as oxygen, between the umbilical cord and the fetus. [9] It allows the fetus to move freely within the walls of the uterus. [citation needed] Buoyancy is also provided.
The human allantois is a caudal out-pouching of the yolk sac, which becomes surrounded by the mesodermal connecting stalk or body-stalk. The vasculature of the body-stalk develops into umbilical arteries that carry deoxygenated blood to the placenta. [12] It is externally continuous with the proctodeum and internally continuous with the cloaca.
The human allantois is a caudal out-pouching of the yolk sac, which becomes surrounded by the mesodermal connecting stalk known as the body-stalk. The vasculature of the body-stalk develops into umbilical arteries that carry deoxygenated blood to the placenta. [5] It is externally continuous with the proctodeum and internally continuous with ...