Histogenesis

• Menarche


  First ever menstruation of women around 9-14 years of age
• Menarche


  • Serves as the last sign of development of secondary characteristics of woman in puberty
• Menopause


  Period when the ovarian activity diminishes; 45-50 years of age
• Ovary


  • Covered by low cuboidal epithelium
  • Layers of ovaries contains surface or germinal epithelium
  • Tunica albuginea: dense connective tissue layer
• Ovarian follicle

  • Primordial follicle
  • Primary follicle
  • Secondary follicle
  • Graffian follicle
  • Corpus luteum
  • Corpus albican
• Primordial follicle

  • Make up the majority of follicles
  • Consists of a large spherical oocyte enveloped by a single layer of squamous follicular cell
  • The only follicles present at birth
• As the follicles grow larger, the follicular cells of the primordial follicles change to cuboidal, or low columnar, and the follicles now become primary follicles.
• Primary follicle formation

  1. Follicular cells proliferate by mitosis

  2. Form layers of cuboidal cells called granulosa cells
• Primary follicle formation


  Stimulated by FSH
• Primary follicle

  • Prominent layer of glycoprotein called zona pellucida develops between granulosa cells and immature oocyte
• Secondary follicle formation

  1. Follicle develops antral cavities

  2. Oocyte displaced to one side by development of fluid-filled antrum
• Antrum


  Produces clear fluid known as liquor folliculi
• Graffian/Mature follicle

  • Largest ovarian follicle
  • Exhibits large antrum filled with liquor folliculi
  • Contains cumulus oophorus mound with primary oocyte
  • Contains corona radiata cell layer attached to primary oocyte
• Corpus luteum formation

  Forms after ovulation and liberation of secondary oocyte
• Corpus luteum

  • Contains granulosa lutein cells and theca lutein cells responsible for producing progesterone and estrogen
• Corpus luteum regression

  If fertilization and implantation do not occur, corpus luteum degenerates into corpus albicans
• Corpus albicans

  • Fibrous-hyalinized tissue containing more collagen and fewer fibroblasts
• Corpus luteum during pregnancy


  Continues to secrete hormones
• In response to FSH and LH, corpus luteum cells secrete estrogen and progesterone which stimulate uterus and mammary gland development
• Primary oocyte

  • Surrounded by zona pellucida and corona radiata cells in follicles
• Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)


  Responsible for later development, maturation, and ovulation of follicles
• During first half of menstrual cycle and follicular growth, FSH is the principal hormone
• Oocyte is viable for about 24 hours before it degenerates if not fertilized
• Without fertilization, the corpus luteum is active for about 12 days before regression