Dictyotene
Dictyotene (also known as the dyctiotene stage ) refers to a resting phase in oogenesis in mammals, including humans. Around 7 million primordial follicles develop by the 5th month of female embryonic development . They enter the dictyotene stage and cease to mature in the prophase of the first division up to puberty. The dictyotene is not a separate stage in prophase I, but the name for the arrested diplotene . At this stage v. a. In the cortical region of the ovary there are many follicles ( ovarian follicles ). At birth, both ovaries together have around 1 million follicles and around 400,000 remain in the cortical region of the ovary until puberty. From puberty to menopause , 5–15 primordial follicles are reactivated and stimulated to maturation each month (only one follicle is ultimately expelled during ovulation , the others die). Some primordial follicles remain in the dictyotan stage for decades (up to menopause).
Individual evidence
- ↑ Ulrich Welsch: Textbook Histology . 2nd Edition. Urban & Fischer, ISBN 3-437-42421-1 , pp. 501 .
- ↑ Lüllmann-Rauch, Renate: Pocket textbook histology: 10 tables . 4th, completely revised Ed. Thieme, Stuttgart.
swell
- Thomas W. Sadler; Medical embryology ; Thieme publishing house; 2003; ISBN 3-13-446610-4
- http://www.embryology.ch/allemand/cgametogen/oogenese01.html
- Entry on Diplotän in Flexikon , a Wiki of the DocCheck company