Quick Facts
The theca externa is the outer, fibrous layer of the follicular theca (Dorland, 2011).
Related parts of the anatomy
Structure and/or Key Feature(s)
The theca externa is the outmost layer of connective tissue surrounding the follicle, containing collagen fibers and fibroblasts but also some smooth muscle cells.
There is no clear boundary between the two thecal layers and the stroma of the ovary. However, because the cells of the theca interna and the granulosa are morphologically different, as well as the existence of a thick basement membrane between them, the boundary between these layers is clear (Ross and Pawlina, 2006; Mescher, 2013).
Anatomical Relations
The theca externa is the outmost layer of connective tissue surrounding the follicle, containing collagen fibers and fibroblasts but also some smooth muscle cells.
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
Mescher, A. (2013) Junqueira's Basic Histology: Text and Atlas. 13th edn.: McGraw-Hill Education.
Ross, M. H. and Pawlina, W. (2006) Histology: A text and atlas. Lippincott Williams & Wilkins.
