Search results
Results from the WOW.Com Content Network
Hippomanes first appears in pregnant horses and zebras ca. 85 days from conception, earlier there being small white flecks of tissue debris instead. [1] The changes in hippomanes color correspond to changes in color of allantoic fluid. [ 1 ]
For example, a cat's gestation normally takes 58–65 days while an elephant's takes nearly 2 years (21 months). [3] However, growth does not necessarily determine the length of gestation for all species, especially for those with a breeding season. Species that use a breeding season usually give birth during a specific time of year when food ...
Another factor is due to the shortage of food stocks during winter as the insects are being driven away and as the result, bat hibernate in pregnant condition. [ 24 ] In pinnipeds , the purpose of delayed implantation is in order to increase survival chance of the young animals as the mother ensure that the neonates are born at an optimal season.
The gestational sac is spherical in shape, and is usually located in the upper part (fundus) of the uterus.By approximately nine weeks of gestational age, due to folding of the trilaminar germ disc, the amniotic sac expands and occupy the majority of the volume of the gestational sac, eventually reducing the extraembryonic coelom (the gestational sac or the chorionic cavity) to a thin layer ...
As pregnancy advances to term, the fetal membranes undergo weakening. [14] The amnion is vital in the synthesis of prostaglandins which reach the myometrium and create and initiate parturition. The chorion expresses chemicals that balance synthesis and metabolism of these prostaglandins to ensure that the myometrium is not activated pre-term.
Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). [1] It is typical for mammals, but also occurs for some non-mammals. Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. [2]
For premium support please call: 800-290-4726 more ways to reach us
Embryonic age: Week nr 1. 0 (whole) weeks old. 1–7 days from fertilization. Fertilization of the ovum to form a new human organism, the human zygote. (day 1 of fertilization [1]) The zygote undergoes mitotic cellular divisions, but does not increase in size. This mitosis is also known as cleavage. A hollow cavity forms marking the blastocyst ...