Are you an EPFL student looking for a semester project?
Work with us on data science and visualisation projects, and deploy your project as an app on top of Graph Search.
Concept
Chorioallantoic membrane
Summary
The Chorioallantoic Membrane (CAM), also known as the chorioallantois, is a highly vascularized membrane found in the eggs of certain amniotes like birds and reptiles. It is formed by the fusion of the mesodermal layers of two extra-embryonic membranes – the chorion and the allantois. It is the avian homologue of the mammalian placenta. It is the outermost extra-embryonic membrane which lines the non-vascular egg shell membrane.
The chorioallantoic membrane is composed of three layers. The first is the chorionic epithelium that is the external layer present immediately below the shell membrane. It consist of epithelial cells that arise from chorionic ectoderm. The second is the intermediate mesodermal layer that consists of mesenchymal tissue formed by the fusion of the mesodermal layer of the chorion and the mesodermal layer of the allantois. This layer is highly vascularized and rich in stromal components. The third is the allantoic epithelium that consists of epithelial cells arising from the allantoic ectoderm. It forms a part of the wall of the allantoic sac.
Both the epithelial layers are separated from the mesodermal layer by basement membranes.
The Chorioallantoic membrane performs the following functions:
The CAM functions as the site of gaseous exchange for oxygen and carbon dioxide between the growing embryo and the environment. Blood capillaries and sinuses are found in the intermediate mesodermal layer allows close contact (within 0.2 μm) with air found in pores of the shell membrane of the egg.
The chorionic epithelial layer contains the calcium transporting region of the CAM, and thus is responsible for the transport of calcium ions from the egg shell into the embryo for the purpose of ossification of the bones of the developing embryo. The CAM also helps in maintaining the acid-base homeostasis in the embryo. Finally the allantoic epithelium serves a barrier to the allantoic cavity, and acts in a selectively permeable manner by permitting the absorption of water and electrolytes, as well as maintains a barrier against the toxins and waste materials stored inside the allantoic cavity.
Official source
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.