Theca interna This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Theca_interna".
The theca folliculi comprise a layer of the ovarian follicles. They appear as the follicles become tertiary follicles.
The theca are divided into two layers, the theca interna and the theca externa.
Theca interna cells express receptors for luteinizing hormone, which when activated will stimulate the production of androstenedione from cholesterol by the enzyme desmolase. Androstenedione ultimately gives the granulosa the precursor for estrogen manufacturing.
After rupture of the mature ovarian follicle, the theca interna cells differentiate into the theca lutein cell of the corpus luteum. These cells secrete progesterone.
The theca externa is the outer layers of the theca folliculi. It contains contain abundant collagen and is mainly supportive.
cervix/neck (External orifice - Canal of the cervix, Internal orifice)