Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Definition: "Acellular anatomical structure that consists of a thin sheet of fibrous proteins that underlie and support the cells of an epithelium. It separates the cells of an epithelium from any underlying tissue."