Chorioallantoic membrane

An article about the chorioallantoic membrane and its applications in research

The chorioallantoic membrane (CAM) is a highly vascularized membrane found in bird and reptile eggs. It is formed by the fusion of the chorion and the allantois, two of the extraembryonic membranes that support the developing embryo. The CAM plays a crucial role in gas exchange and calcium absorption during embryonic development.

Smallpox lesions on the chorioallantoic membrane

Structure and Function

The chorioallantoic membrane is composed of three layers: the ectoderm, mesoderm, and endoderm. The ectoderm is the outermost layer, which is in contact with the eggshell. The mesoderm contains a rich network of blood vessels, facilitating the exchange of gases and nutrients. The endoderm is the innermost layer, adjacent to the allantoic cavity.

The primary function of the CAM is to facilitate respiratory gas exchange for the developing embryo. Oxygen from the external environment diffuses through the eggshell and the CAM to reach the embryo, while carbon dioxide produced by the embryo is expelled in the opposite direction. Additionally, the CAM is involved in the absorption of calcium from the eggshell, which is essential for the development of the embryonic skeleton.

Applications in Research

The chorioallantoic membrane is widely used in scientific research due to its accessibility and similarity to human tissues. It serves as a model for studying angiogenesis, the process of new blood vessel formation, which is crucial in cancer research. The CAM assay is a popular method for testing the effects of drugs on angiogenesis.

The CAM is also used in virology for the cultivation of viruses. For example, the image to the right shows smallpox lesions on the CAM, demonstrating its use in studying viral infections. The membrane provides a suitable environment for the growth and observation of viral pathogens.

Related pages

• Embryonic development
• Angiogenesis
• Virology
• Extraembryonic membranes