Mammal, canine ovary (LM, Low)

Structure List Primordial follicle Primary follicle Secondary follicle Regressing corpora lutea Low Magnification View

PRIMORDIAL FOLLICLE. In most mammals the OOGONIA have formed primordial follicles at the time of birth. It is generally believed that all of the primordial follicles that are going to develop are present at the birth of the animal. The primordial follicle is a single egg or oocyte surrounded by a single layer of flattened cells called the follicular cells. Many of the follicles will not develop and will undergo a gradual breakdown or atrophy: this process is called atresia and the follicles are said to be atretic.