Histology of Ovary and Female Tract Flashcards
Main structures of the ovary
Surface epithelium (sometimes called germinal epithelium but this is wrong)
Tunica albuginea- connective tissue just below epithelium
Cortex- parenchymatous zone containing the follicles
Medulla- vascular,nerves, lymphatics, fibroblasts
Stroma- emryonal mesenchymal-like cells
Smooth muscle
Ovary- oocyte/ovum/egg
Surrounded by…
Germ cell
-surrounded by zona pellucida
Name this structure
On anki cards reproduction
What is zona pellucida?
product of the inner most layer of granulosa cells
-gelatinous layer surrounding oocyte that’s got a lot of mucus polysaccharides, proteins, receptor (sperm receptors) etc.
What is menarche?
Start of menstruation
How many oocytes found in the ovaries during:
-birth
-menarche
-menopause
- 0.6-2 x 10^6
- 3-4 x 10^5
- 1-2 x 10^2
What is the first stage of folliculogenesis?
Primordial follicles
- oocytes surrounded by 1 layer of quiescent (not doing anything) pre-granulosa cells
What’s depicted in this histology image?
On anki
When do primordial follicles start appearing and where. Any functions?
Mid gestation in female foetus. No functions just sit and do nothing
The number of primordial follicles found in ovary affected by what factors?
Species (0.4-3x10^5; sheep)
Breed
Age
Nutritive status eg of the mum (incl. foetal/neonatal stages)
Once primordial follicles start to grow, what are they called?
Primary follicles
Primary follicles of ovary
-appearance
-surrounded by
-once follicle turns primary can it turn back to primordial?
More cuboidal appearance- bigger in size (on anki)
Surrounded by interstitial tissue
NO IT CANNOT TURN BACK; EITHER KEEPS GROWING OR DIES OFF
Secondary follicles of ovary (also called preantral follicles)
-appearance
-what starts to form
-cuboidal and bigger again
-basement membrane and theca layer; theca intera & thecal external
How long does a follicle start growing (to point of ovulation)?
6 months
Why is theca layer important?
They’re the ones getting information/signals from outside eg contain receptors,hormones
What is a Hypophysectomy
surgery done to remove the pituitary gland
Tertiary follicles of the ovary (also called vesicular or antral)
-made up of…
-are dependant on…
-contains antrum, oocyte, theca interna & externa, cumulus ophrus and granulosa cells
-dependant on gonadotrophins for growth (growth driven by FSH)
-steroidogenesis increases markedly (E2 i.e oestrogen increases with increasing size
What is antrum
A hole formed between dissociated cells caused by fluid build up between the cells- filled up with fecal blood
Final stage follicle- preovulatory follicle of the ovary
-found at which point in process
-size
-found at point of ovulation
-very enlarged, protruding from ovarian surface
What is ovulation
the process in which a mature egg is released from the ovary. Egg/oocyte matures in a follicle which grows and develops in thee stages described before
What are the stages of follicle growth
- Primordial
- Primary
- Secondary
- Tertiary
- Preovulatory
Where does ovulation occur?
-any exceptions
Occurs at random from the surface
-except at hilus
-in mare- only in ova fossa
What triggers ovulation?
Hormones
-E2 (oestrogen)
Atretic follicles
-what are they
-2 types
Follicles which have been destroyed- done by apoptosis
-99.9% of follicles die; lost at antral stage of development (when gonadotrophin-dependant)
-early Atretic—>a few necrotic granulosa cells
-late Atretic—> Degeneration of GC (granulosa cell) layer, oocyte shrinkage, pyknotic nuclei & call-exner bodies
