What do lungs and intestines have in common? Both of these organs actually develop from one layer of embryo tissue. What is an endoderm? What other structures are formed from the germ layer?
Gastrulation and germinal layer (endoderm)
During early development, most animals go through the so-called gastrulation process, where germ cells form various embryonic leaves. What is an endoderm? This is the inner layer of the embryo, surrounded by the mesoderm and ectoderm. Some living things may not have a middle layer. For example, jellyfish, sea anemones, corals and ctenophores lack mesoderm. Each of these layers of tissue will develop into different adult structures.
The three main layers of the embryo
With the formation of the three main layers of the embryo, the process of tissue differentiation begins. Each of the three primary germ layers will form a set of specific organs and types of tissue in the animal.
- From the ectoderm, epithelial cells of the mammary glands, lenses of the eyes, hair, pigment cells, the nervous system and epidermis of the skin are formed.
- Skeletal muscles, smooth muscles, heart, blood vessels, blood cells, kidneys, spleen, fat cells, skeleton, most connective tissues and the entire genitourinary system are formed from the mesoderm.
- From the endoderm, the entire epithelial lining of the gastrointestinal tract is formed, as well as the liver, pancreas, gall bladder, thyroid gland, epithelial lining of the trachea and respiratory surface of the lungs.
Derivatives of the Endoderm
For example, in a person, the ectoderm turns into the nervous system and the outer layer of the skin, the mesoderm forms the majority of organ systems, including skeletal and muscular, and from the endoderm internal tissues and organs develop. Parts of the digestive tract, respiratory and urinary tracts, as well as a number of internal organs develop from the germinal leaf of the endoderm. The internal epithelial lining of the gastrointestinal tract is formed from these tissues. This includes the mouth, pharynx, esophagus, stomach, intestines, and anus. Although the mucous membranes of the mouth and anus (their outermost parts) actually come from the ectoderm.
What is endoderm in biology? This is an embryonic leaf, which, as it develops, is converted into internal organs and tissues. If we continue to give an example of a person, then the respiratory tract from the nose to the lungs can also be attributed here. The tissue in the inner passages of the nose consists of an ectoderm, and the larynx, trachea, small tubes that lead to the lungs, and their respiratory surface, are made of endoderm.
The inner layer
The embryo consists of three main layers of cells - internal, middle and external. What is an endoderm? This is the inner layer that forms in the early stages of embryonic development. The layers of the embryo during gastrulation ultimately give rise to certain types of tissue in the body.
What is an endoderm and why is it called so? This is the innermost of the three layers of the embryo. Since germ cells can differentiate into various organs and tissues, they are of particular interest for studying human development and stem cell research.