Ectoderm (Gr. Ektos - Outside, Dermis - Skin)

Ectoderm (from the Greek words “ectos” - outside and “derma” - skin) is one of the two germ layers of the gastrula, formed during the embryonic development of many multicellular organisms. This germ layer extends outward from the endodermis, which forms the internal organs.

The ectoderm plays an important role in the formation of the skin and nervous system of the body. From this germ layer the epidermis (the upper layer of the skin) and all its accessory organs, such as hair, nails, sweat and sebaceous glands, are formed. The ectoderm also forms the nervous system, including the brain, spinal cord and peripheral nerves.

The development of the ectoderm begins with the formation of the neural plate, which gradually closes and forms the neural tube. From this tube the central nervous system develops, as well as some parts of the peripheral nervous system.

In addition, the ectoderm is involved in the formation of several other organs and tissues, such as the eyes, ears, nose, teeth and bone cartilage. This occurs due to the interaction of the ectoderm with other germ layers and special cells called mesenchymal cells.

Some diseases and abnormalities are associated with abnormal development of the ectoderm. For example, defects in the neural tube can lead to various neurological disorders, and abnormalities in skin development can lead to various dermatological diseases.

Thus, the ectoderm is an important germ layer that plays a decisive role in the formation of the skin and nervous system of the body. Its improper development can lead to serious diseases and abnormalities, so studying the mechanisms of its development is of great importance for medicine and biology in general.