The mesoderm is one of the three primary germ layers formed during embryonic development, alongside the ectoderm and endoderm. It plays a crucial role in the formation of various structures in the body, including muscles, bones, and the circulatory system. The mesoderm is responsible for developing many internal organs and tissues, making it essential for proper body function. During the process of gastrulation, the mesoderm is created from the inner cell mass of the developing embryo. It differentiates into several subtypes, such as paraxial mesoderm, which forms somites, and lateral plate mesoderm, which contributes to the formation of the heart and blood vessels. Understanding the mesoderm is vital for studying developmental biology and congenital disorders.