develops from theca cell atretic follicular cell of ovary atretic theca cell 2024-11-06T10:10:51Z A theca cell undergoing atresia, characterized by distinct morphological changes including hypertrophy, altered cell shape, and disrupted layered organization. This cell exhibits reduced steroidogenic capacity and changes in surrounding vascularization. The onset of theca cell atresia can vary, occurring at different stages of follicle atresia depending on the phase of folliculogenesis. During atresia, theca interna and externa cells undergo distinct morphological and functional changes. Theca interna cells round up, expand in cytoplasmic area, and thicken the internal layer as organization degrades, while showing reduced STAR expression, which lowers androgen production. Theca externa cells display decreased ACTA2 expression, weakening structural integrity.