Endocytosis is defined as the uptake of material by the invagination of plasma membrane. The rest of the invagination is classified as the cytopharynx. Each tracheal tube develops as an invagination of the ectoderm during embryonic development. This buckles inwards towards the blastocoel in a process called invagination. Basilar invagination can be present at birth. There is more than one type of movement for invagination. Over-excitation of this receptor induces receptor remodeling and the eventual invagination of the GABA receptor. During gastrulation, the blastula will be transformed by the invagination. Cytoplasmic material is trapped in the lysosome/vacuole by a random process of membrane invagination. The anterior pituitary arises from an invagination of the oral ectoderm and forms Rathke's pouch. The invagination in "Amphioxus" is the first cell movement of gastrulation. It is formed by an invagination of the hyaloid membrane, which encloses the vitreous body. In deuterostomes, the mesoderm forms by enterocoelic pouching, through invagination of the endoderm. Later, the blastopore will be formed and with this, the invagination process is complete. The four largest endoderm cells induce the invagination process in the tunicates.