Mammal, canine ovary (LM, Low)

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

The PRIMARY FOLLICLE develops from the primordial follicle and is characterized by several layers of follicular cells surrounding the oocyte. The follicular cells become more cuboidal and secretory in appearance and are referred to as granulosa cells. At this time, a clear layer of extracellular material, called the zona pellucida, can be seen around the oocyte.