Extra-Embryonic Membranes and Placentation

<p>Splanchnopleure (B)</p> Signup and view all the answers

<p>It atrophies during development. (D)</p> Signup and view all the answers

<p>The amnion fuses with the chorion. (D)</p> Signup and view all the answers

<p>Providing a reservoir for waste storage (C)</p> Signup and view all the answers

<p>Involvement of the allantois (A)</p> Signup and view all the answers

<p>To protect the embryo within a fluid-filled sac (A)</p> Signup and view all the answers

<p>Placenta (A)</p> Signup and view all the answers

<p>Facilitation of gas exchange and waste removal (D)</p> Signup and view all the answers

<p>Facilitating attachment of the embryo to the uterine wall (A)</p> Signup and view all the answers

<p>Some species float in the uterine lumen before implanting (A)</p> Signup and view all the answers

<p>Lack of observable signs of fertilization (A)</p> Signup and view all the answers

<p>They are exclusively responsible for nutrient transport (B)</p> Signup and view all the answers

<p>To facilitate oxygen and nutrient transfer from the mother (A)</p> Signup and view all the answers

<p>Creation of an aqueous environment (B)</p> Signup and view all the answers

<p>Splanchnic (extra-embryonic) mesoderm (C)</p> Signup and view all the answers

<p>Allantois (A)</p> Signup and view all the answers

<p>Very vascular with little or no yolk (D)</p> Signup and view all the answers

<p>Chorion (B)</p> Signup and view all the answers

<p>Splanchnopleure (B)</p> Signup and view all the answers

<p>Avascular (D)</p> Signup and view all the answers

<p>By their corresponding extra-embryonic mesoderm layers (B)</p> Signup and view all the answers

The gastrula is divided into embryonic and extra-embryonic regions at the periphery of the embryonic disc.

The placenta initially develops with only endoderm and trophoblast.

Splits into somatic (adjacent to trophoblast) and splanchnic (adjacent to hypoblast) layers.

Combination of somatic mesoderm and trophoblast.

Combination of splanchnic mesoderm and endoderm.

Develops from splanchnopleure, contains little yolk in mammals, and is vascular.

Develops from splanchnopleure, stores urinary waste, and is vascular.

Develops from the somatopleure, outermost layer, part of placenta, and avascular.

The somatopleure folds over the embryo, separating and forming the amnion, a membrane surrounding the amniotic cavity.

The remaining somatopleure, after the amnion forms, encompassing the entire embryo, becomes the chorion.

A type of placenta formed by the union of the chorion and yolk sac.

A type of placenta formed by the union of the chorion and allantois.

A secondary outgrowth of the hindgut; it develops splanchnic mesoderm and expands into the extra-embryonic coelom, replacing the yolk sac.

Structures outside the embryo that support its development.

A fluid-filled cavity surrounded by the amnion that cushions the developing embryo.

The process of developing blood vessels to transport nutrients in the extra-embryonic membranes.

The process where an embryo burrows into the uterine lining to connect with the mother's blood supply. This creates a placenta and is essential for exchanging nutrients and oxygen.

The placenta is the interface between the embryos vascular system and the mother's blood supply. It allows for the exchange of oxygen, nutrients, and waste products between the mother and developing fetus.

In species giving birth to multiple offspring, embryos need to be evenly spaced in the uterus. This ensures each embryo has enough blood supply and room to grow properly.

The embryo's tissues are protected from the mother's immune system to prevent rejection. This allows the embryo to develop safely within the womb.

The embryo needs to signal the mother that she is pregnant so her body can adjust accordingly for pregnancy. This process varies between species.

The timing of implantation varies depending on the species. However, often it starts around when gastrulation is completed.

Research on implantation can be challenging due to differences in timing between species, and because the starting point for measuring this process can vary (ovulation, fertilization, etc.).

Understanding implantation is crucial as it is essential for pregnancy and fetal development. Studying this process helps us understand how pregnancy occurs and how to address pregnancy complications.