Changes in vaginal epithelium of the ***** as she progresses through the oestrus cycle?

vaginal epithelium during pro-oestrus?

follicles begin to develop and rising oestrogen concentrations are exhibited in ovaries. this period usually lasts 10 days and as it progresses the reproductive tract changes and the epithelium becomes greatly increased and thickened. reaching up tp 15-25 cells thick and keratinised. these cells are flat and large and serve as a protective barrier to the vagina. as pro oestrus continues, the thickening of the epithelial lining pushes the surface cells further from their blood supply which results in characteristic changes.

what happens when the surface cells are pushed further from their blood supply in canines during pro-oestrus?

in early pro oestrus as well as keratinised cells a high amount of RBCs are present due to their diapedesis from the congested uterine blood vessels. three types of cells from the basal intermediate and superficial layers are seen.

when does peak cornification take place?

occurs when progesterone begins to rise. bacteria are present until the end of oestrus.

what are the three types of cells that are present from the three different layers during proestrus?

parabasal cells are small round cells with vesicular nuclei and deeply staining cytoplasm. intermediate cells are polygonal cells with vesicular nuclei and are non keratinised. the superficial cells are large polygonal cells with vestigial nuclei or in some cases no nuclei. they are usually keratinised.

staging cycle based on cytology?

progression of parabasal cells to fully cornified cells by oestrus. at the beginning of proestrus almost all the cells are parabasal with a few intermediate being seen. as proestrus progresses the number of cornified cells increases until they make up 100% of the smear. this will persist for 10-14 days after which there will be a sharp decline. on the day of ovulation the cells have been cornified at peak for 6 days approximately as the peak will coincide with progesterone release in late pro oestrus. because ova need 2-3 days for capacitation, the bitch should be bred 4-5 dos after the smear reaches peak cornification

vaginal cytology?

tracking the changes in vaginal epithelium via cytology is a cheap quick and easy method method od determining the stage of the bitch in the oestrus cycle.

epithelium during oestrus?

keratinisation is at its highest and decreases slowly after this stage. smears contain squamous keratinised cells which are flat and irregular in shape with angular sides going them a characteristic cornflake appearance. white blood cells are also absent.

epithelium of vagina composition?

lined by stratified squamous epithelium. the rising levels of oestrogen cause the vaginal epithelium to become cornfield. the surface cells become filled with keratin, large and flattened and lose their nuclei i.e. vaginal cytology.

mid to late pro-oestrus?

more keratinised cells are seen, bacteria are seen and there is a decrease in leukocytes. this is because the increasingly keratinised squamous epithelium becomes increasingly impervious to white blood cells. they are therefore absent in oestrus proper when keratinisation is at its greatest.

response of vaginal epithelium of the bitch to hormones?

the epithelium is extremely responsive to sex steroids i.e. oestrogen in particular. it undergoes predictable changes through the cycles in response to changes in the concentration of the ovarian hormones in the blood.

metoetrus epithelium?

the number of epithelial cells decrease as does the keratinisation. there is a sudden return of parabasal cells. these keratinised layer of the epithelium sloughs off. the smears are characterised by non keratinised squamous epithelial cells. neutrophils also return. these return at the early stages of metoestrus. however they decrease progressively into metoestrus. debris is also found in the smears and the bacteria are absent.

vaginal epithelium during anoestrus?

the vaginal epithelium is only a few cells thick 2-3 and is composed of small cuboidal cells and there is no keratinisation. the exfoliative cytological smears show a smaller number of ells present in comparison with other stages of the cycle. these cells are unstained non keratinised squamous cells. a few larger stained epithelial cells neutrophils and lymphocytes may be present too. this is due to low oestrogen levels characterised by anoestrus, as there are no dominant follicles producing large concentrations of oestrogen.