Talk:BGDA Practical - Female Reproductive Tract Histology

From Embryology


Primordial Follicle

are located in the cortex just beneath tunica albuginea. One layer of flattened follicular cells surround the oocyte (about 30 µm in diameter). The nucleus of the oocyte is positioned eccentric in the cell. It appears very light and contains a prominent nucleolus. Most organelles of the oocyte aggregate in the centre of the cell, where they form the vitelline body (probably not visible in any of the available preparations).

Primary Follicle


is the first morphological stage that marks the onset of follicular maturation (Which hormone stimulates follicular maturation and where is this hormone produced?). The previously flattened cell surrounding the oocyte now form a cuboidal or columnar epithelium surrounding the oocyte. Their cytoplasm may have a granular appearance, and they are for this reason also called granulosa cells. The continued proliferation of these cells will result in the formation of a stratified epithelium (with a distinct basement membrane) surrounding the oocyte. The zona pellucida (glycoproteins between interdigitating processes of oocyte and granulosa cells) becomes visible. Parenchymal cells of the ovary surrounding the growing follicle become organised in concentric sheaths, the theca folliculi.

Secondary Follicle


Small fluid-filled spaces become visible between the granulosa cells as the follicle reaches a diameter of about 400 µm. These spaces enlarge and fuse to form the follicular antrum, which is the defining feature of the secondary follicle. The oocyte is now located eccentric in the follicle in the cumulus oophorus, where it is surrounded by granulosa cells. The theca folliculi differentiates with the continued growth of the follicle into a theca interna and a theca externa. Vascularization of the theca interna improves, and the spindle-shaped or polyhedral cells in this layer start to produce oestrogens. The theca externa retains the characteristics of a highly cellular connective tissue with smooth muscle cells. The oocyte of the secondary follicle reaches a diameter of about 125 µm. The follicle itself reaches a diameter of about 10-15 mm.

Tertiary Follicle

(mature, preovulatory or Graafian follicle)

increases further in size (in particular in the last 12h before ovulation). The Graafian follicle forms a small "bump" on the surface of the ovary, the stigma (or macula pellucida). The stigma is characterised by a thinning of the capsule and a progressive restriction of the blood flow to it. Prior to ovulation the cumulus oophorus separates from the follicular wall. The oocyte is now floating freely in the follicular antrum. It is still surrounded by granulosa cells which form the corona radiata. The follicle finally ruptures at the stigma and the oocyte is released from the ovary.

BGDA Manual 2018

Virtual Slides - Ovary Cat/Human

In the ovary slide identify: the germinal epithelium, dense CT layer (tunica albuginea), cortex, medulla, CT stroma, primordial follicles, developing follicles with a fluid filled antrum, a mature follicle with an oocyte containing a nucleus and surrounded by a zona pellucida, corona radiata, cumulus oophorus, theca interna and externa, atretic follicles, a corpus luteum and corpus albicans.

  • What resides in the cortical as compared to the medullary region of the ovary? What is a corpus albicans?
  • In the corpus luteum slide identify: the theca lutein and granulosa lutein cells and give their collective function.
  • What resides in the central core of the corpus luteum?
  • What is the function of the corpus luteum?

Virtual Slides - Oviduct

(uterine tube, Fallopian tube)

  • Note the irregular lumen formed by mucosal folds.
  • What type of epithelium lines the oviduct?
  • The lamina propria has loose CT (collagen and reticular fibers), and blood vessels.
  • The muscularis has inner circular and outer longitudinal smooth muscle layers.
  • The outer layer (serosa) has CT, blood vessels, and nerves.
  • What is the function of the oviduct?

Virtual Slides - Uterus

Uterus: proliferative phase / Uterus: secretory phase

Proliferative Phase

  • Identify the inner endometrium and the middle myometrium layers
  • What type of epithelium lines the endometrium?
  • Identify the long branching tubular uterine (endometrial) glands secreting nutrients especially glycogen.
  • The endometrium also exhibits coiled (spiral) arteries.
  • Note the compact and irregular bundles of smooth muscle in the myometrium separated by thin strands of CT. The myometrium is also very vascular.

Secretory Phase

  • The secretory phase of the menstrual cycle exhibits a thickening of the endometrium due to increased glandular secretions and fluid build up in the lamina propria.
  • Note that the uterine glands become highly tortuous filled with nutritive material.
  • The myometrium is similar in this phase to that in the proliferative phase.

Virtual Slides - Cervix

  • Identify the cervical canal and the transition of the epithelium between the cervix of the uterus and the vagina.
  • What types of epithelia are present in the transition area?
  • Identify the cervical glands (Nabothian).
  • What type of secretion do these glands produce and does the viscosity change during various stages of the menstrual cycle?
  • Identify the lamina propria with connective tissue, blood vessels, nerves and lymphatic tissue. Note that the muscularis layer has regions of smooth muscle.

Virtual Slides - Vagina

  • Classify the epithelium.
  • Observe the absence of glands and note the presence of vascular tissue and smooth muscle.

Virtual Slides - Mammary gland

Mammary gland: inactive and active

  • Identify secretory alveoli, interlobular CT septa, lactiferous ducts, adipose tissue and blood vessels
  • What differences occur between an inactive and active mammary gland?