Menstrual cycle and the lining of the uterus thickens. Follicles in the ovary begin developing under the influence of a complex interplay of hormones, and after several days one or occasionally two become dominant (non-dominant follicles shrink and die). Approximately mid-cycle, 24–36 hours after the luteinizing hormone (LH) surges, the dominant follicle releases an ovocyte, in an event called ovulation. After ovulation, the ovocyte only lives for 24 hours or less without fertilization while the remains of the dominant follicle in the ovary become a corpus luteum; this body has a primary function of producing large amounts of progesterone. Under the influence
Navicular cell Navicular cell Navicular cell is a boat-shaped benign epithelial cell seen in Pap smear. They are seen in pregnancy (most prominently during smears taken in the second trimester), second half of menstrual cycle, during menopause and in women using medroxyprogesterone acetate (depo-provera) for contraception. Navicular cells have folded edges, with a thickened outer rim of cytoplasm and an eccentric nucleus. They contain abundant glycogen in the cytoplasm, giving it a central yellow halo. The cytoplasm appears golden, refractile and granular under the microscope. In depo-provera users, the high progesterone levels result in more exfoliation of superficial squamous cells, thereby causing