Gastrulation is the process of embryo development that occurs after fertilization of the egg. At this stage, the embryo experiences the formation of three main layers called the germ layer or blastrula. These three layers are endoderm, mesoderm, and ectoderm.
- Endoderm is the innermost layer that will develop into organs in the body, such as the lungs, liver and intestines.
- Mesoderm is the middle layer that forms connective tissue, muscles, bones and the reproductive system.
- Ectoderm is the outermost layer that will become the skin, nervous system and eyes.
Gastrulation usually begins with the formation of a disc of cells called a blastula. The blastula then undergoes movement and invagination to form the germ layers. This process is important for forming complex body structures and organs in the next stage.
For example, in humans, gastrulation occurs approximately 14 days after fertilization and forms the initial structures of the body such as the lining of the abdominal cavity (endoderm), connective and muscle tissue (mesoderm), and the skin and nervous system (ectoderm).
In gastrulation, each germ layer has an important role in embryo development and forms important parts in the human body.
What is
Gastrulation is the process of forming organs in the embryo that forms body tissue and separates organs in the body. This entire process starts from the three main phases in embryo development, namely cleavage, gastrulation, and organogenesis.
In the cleavage phase, the embryo cells form a blastula, which consists of a stiff cell layer outside and a soft cell layer inside. Then, in the gastrulation phase, the soft layer of cells in the blastula hangs down and undergoes movement to become the heart, lung plug, and urinary tract.
Gastrulation is one of the three main phases in embryonic development, the others being cleavage and organogenesis. This process takes place during the 14-16th day of pregnancy in women who are pregnant.
Type
Gastrulation is a process of embryonic development that involves the formation of three germ layers: endoderm, mesoderm, and ectoderm. There are several types of gastrulation that can occur, depending on the organism that is undergoing the process.
Following are some common types of gastrulation:
- Invaginated Gastrulation: In this type of gastrulation, the cells in the blastula move inwards to form a depression called the blastopore. This blastopore will later form a body cavity such as the mouth or anus in adult organisms. An example is gastrulation which occurs in humans and animals such as frogs.
- Delamination Gastrulation: In this type of gastrulation, the cells in the blastula split into two distinct layers horizontally. Usually there is an endoderm layer formed inside and an ectoderm layer outside. An example is gastrulation which occurs in some invertebrate animals such as flatworms.
- Involuted Gastrulation: In this type of gastrulation, the cells in the blastula undergo an inward rolling movement, forming an endoderm layer inside and an ectoderm layer outside. An example is gastrulation which occurs in animals such as echinoderms, including sea urchins.
Each type of gastrulation has unique mechanisms and characteristics, but its aim is to form the three germ layers which are the basis for the formation of the body’s organs in the next stage.