The<unk>  is a part of the brain which is involved in stereotypical actions, such as walking, sleeping, and lying down. It is essential for governing some of the basic functions of higher organisms, and phylogenetically one of the oldest portions of the brain.
Reticular formation
Neurulation
Epithelial mesenchymal transition
Tissue expansion
Intramembranous ossification
Bauxite fibrosis
Pseudocyesis
Degranulation