The amniotic egg allows<span> reptiles, birds and mammals to lay eggs on </span>land<span> ... The allantois layer </span>allows <span>gases and waste to escape from the inner </span>part<span> of the egg.</span>
The amniotic egg corresponds to an egg that has an amniotic vesicle, a liquid responsible for protecting the embryo against dehydration and rapid changes in temperature.
The first animals to develop this structure were reptiles. The main importance of the emergence of the amniotic egg for the evolution of animals was that it enabled greater independence of the aquatic environment so that the animals could reproduce.
Amniotic Egg Parts:
Eggshell: impact and dehydration protection, source of calcium for the embryo.
Bark membrane: protection against dehydration (prevents water loss).
Chorion or chorion: protection for the yolk sac and the embryo. Chorionic villi invade the endometrium and allow nutrient transfer from maternal blood to the fetus. In addition, the chorion joins with the allantoid (in birds and reptiles) to form the allantoic with respiratory function (promotes fetal gas exchange with the environment). In reptiles and birds the chorion is located just below the bark (gas exchange) and in mammals it is part of the placenta and is also involved with the removal and accumulation of metabolism residues.
Tube: Air reserve for the embryo.
Vitellin sac or Calf: food reserve (consisting of lipoproteins, vitamins, cholesterol).
Allantoid: deposit of protein metabolism residues (excreta); It is responsible for the gas exchange of the embryo with the environment and mobilizes the calcium from the shell to develop the bones of the embryo.
Ammonium: protects against trauma (mechanical shocks) and prevents dryness (dehydration) of the embryo.
