The origin of human epithelial tissue Alaminos Mingorance, Miguel Campos Muñoz, Antonio Jesús Histology Epithelium Evolution The histological structure of human epithelial tissue is complex, but all epithelia share three major features: cohesion, polarity and attachment. These functions are mainly achieved by the presence of specialized structures such as intercellular junctions, polarity protein complexes and basement membranes. In the present review, we have analyzed the presence of each of these structures in several groups of animals that are considered to be at the base of the animal evolution tree. Interestingly, these characters seem to have evolved independently, and a careful histological and structural analysis of the phylogenetic tree shows different groups of animals in which epithelia are absent and groups in which cells show only some of the specialized structures found in differentiated epithelia. These findings could contribute to understand how epithelial tissues evolved and determine their current protective functions. 2024-02-23T08:36:46Z 2024-02-23T08:36:46Z 2023-02 journal article Alaminos M, Campos A. The origin of human epithelial tissue. Histol Histopathol. 2023 Feb;38(2):127-138. doi: 10.14670/HH-18-485 https://hdl.handle.net/10481/89491 10.14670/HH-18-485 eng http://creativecommons.org/licenses/by/4.0/ open access Atribución 4.0 Internacional PubMed