Description
Thecal tissue forms a layer around the follicle just prior to antral stage and grows with the follicle (containing an oocyte) as it matures. The innermost component (theca interna) supplies hormones and other factors necessary to the growth and development of the granulosa and oocyte. Most follicles regress and die (become atretic) at the antral stage, and this process as well as development of the follicle are undoubtedly influenced by the theca.