Changes

[[File:lighterstill.jpg]][[File:Umbilical-cord-200.jpg|right|frame]]

[[File:lighterstill.jpg]][[File:Umbilical-cord-200.jpg|right|frame]]

*[http://en.wikipedia.org/wiki/18th_century 1753]

*[https://en.wikipedia.org/wiki/18th_century 1753]

==Definitions==

==Definitions==

*1a : a cord arising from the navel that connects the [[fetus]] with the [[placenta]] and through which [[respiratory]] gases, nutrients, and wastes pass

*1a : a cord arising from the navel that connects the [[fetus]] with the [[placenta]] and through which [[respiratory]] gases, nutrients, and wastes pass

==Description==

==Description==

In placental [[mammals]], the '''umbilical cord''' (also called the 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 [http://en.wikipedia.org/wiki/Umbilical_arteries umbilical arteries]) and one vein (the umbilical vein), buried within [http://en.wikipedia.org/wiki/Wharton%27s_jelly Wharton's jelly]. The umbilical vein supplies the fetus with oxygenated, nutrient-rich [[blood]] from the [[placenta]]. Conversely, the fetal heart pumps deoxygenated, nutrient-depleted blood through the umbilical arteries back to the placenta.[http://en.wikipedia.org/wiki/Umbilical_cord]

In placental [[mammals]], the '''umbilical cord''' (also called the 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 [https://en.wikipedia.org/wiki/Umbilical_arteries umbilical arteries]) and one vein (the umbilical vein), buried within [https://en.wikipedia.org/wiki/Wharton%27s_jelly Wharton's jelly]. The umbilical vein supplies the fetus with oxygenated, nutrient-rich [[blood]] from the [[placenta]]. Conversely, the fetal heart pumps deoxygenated, nutrient-depleted blood through the umbilical arteries back to the placenta.[https://en.wikipedia.org/wiki/Umbilical_cord]

In some [[animals]], the [[mother]] will gnaw through the cord, thus separating the [[placenta]] from the [[offspring]]. It (along with the placenta) is often eaten by the mother, to provide nourishment and to dispose of tissues that would otherwise attract scavengers or predators. In chimpanzees, the mother focuses no [[attention]] on umbilical severance, instead nursing her baby with cord, placenta, and all, until the cord dries and separates within a day of [[birth]], at which time the cord is discarded. (This was first documented by zoologists in the wild in 1974.

In some [[animals]], the [[mother]] will gnaw through the cord, thus separating the [[placenta]] from the [[offspring]]. It (along with the placenta) is often eaten by the mother, to provide nourishment and to dispose of tissues that would otherwise attract scavengers or predators. In chimpanzees, the mother focuses no [[attention]] on umbilical severance, instead nursing her baby with cord, placenta, and all, until the cord dries and separates within a day of [[birth]], at which time the cord is discarded. (This was first documented by zoologists in the wild in 1974.

The term "umbilical cord" or just "umbilical" has also come to be used for other cords with similar [[functions]], such as the hose connecting a [http://en.wikipedia.org/wiki/Surface_supplied_diving surface-supplied diver] to his surface supply of air and/or heating, or a [http://en.wikipedia.org/wiki/Space-suit space-suited] [http://en.wikipedia.org/wiki/Astronaut astronaut] to his spacecraft. Engineers sometimes use the term to describe a [[complex]] or critical cable connecting a component, especially when composed of bundles of conductors of different colors, thickness and types, terminating in a single multi-contact disconnect.

The term "umbilical cord" or just "umbilical" has also come to be used for other cords with similar [[functions]], such as the hose connecting a [https://en.wikipedia.org/wiki/Surface_supplied_diving surface-supplied diver] to his surface supply of air and/or heating, or a [https://en.wikipedia.org/wiki/Space-suit space-suited] [https://en.wikipedia.org/wiki/Astronaut astronaut] to his spacecraft. Engineers sometimes use the term to describe a [[complex]] or critical cable connecting a component, especially when composed of bundles of conductors of different colors, thickness and types, terminating in a single multi-contact disconnect.

[[Category: Physiology]]

[[Category: Physiology]]