Difference between revisions of "Cervix - Anatomy & Physiology"

Revision as of 11:42, 9 September 2008

Thick-walled
Non-compliant (firm)
Mare and carnivores have a simple cervix bulging into the vagina to form a distinc recess (vaginal fornix).
Lumen is the cervical canal
Folds surround the lumen
- Single fold and smooth surface in the queen and bitch
- Multiple folds protruding into the cervical canal in the cow, ewe, sow and mare

High volume of mucous production
Multiple folds
Cervical rings form interlocking finger-like projections known as interdigitating prominences.

Provides a physical barrier to the uterus therefore preventing abortion due to infection by isolating the foetus from the external environment. It does this by creasing a highly viscous mucous plug. Closure is via the mucosal folds.
Barrier to sperm transport in the ewe, cow, bitch and queen, but not in the sow and mare.
Assists with the storage and survival of sperm by admitting sperm to the genital tract at a time when fertilisation is possible (around ovulation).
Mucus production for lubrication and to prevent microorganisms from entering the uterus.
Remodels itself at the end of gestation to allow birth and to stimulate the development of maternal behaviour.

Histological Section of the Cerix of a Ewe- Courtesy of J.Bredl, Copyright RVC 2008

The lumen of the cervix is lined by a simple columnar epithelium containing many mucous producing cells. Some cilia may be seen on these cells.
Uterine cervix protrudes into the upper vagina and contains the endocervical canal that links the uterine cavity with the vagina.
The endocervical canal is lined by a single layer of tall columnar mucus-secreting cells.
Where the cervix is exposed to the vagina (the ectocervix), it is lined by thick stratified squamous epithelium.
- Cells of the ectocervix often have clear cytoplasm due to their high glycogen content.
The junction between the vaginal and endocervical epithelium is abrupt, normally located at the external os. This is the point where the endocervical canal opens into the vagina.
The main bulk of the cervix is composed of tough, collagenous tissue with relatively little smooth muscle.
Under the squamocolumnar junction, the cervical stroma is infiltrated with leukocytes which defend against microorganisms.
It is the cervical stroma that is influence by the ovarian hormones.

Uterine artery off the Internal Iliac artery (External Iliac artery in the Mare).

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 [[Image:Ewe Cervix.jpg|thumb|right|150px|Histological Section of the Cerix of a Ewe- Courtesy of J.Bredl, Copyright RVC 2008]]
+* The lumen of the cervix is lined by a simple columnar epithelium containing many mucous producing cells. Some cilia may be seen on these cells.
 * Uterine cervix protrudes into the upper vagina and contains the endocervical canal that links the uterine cavity with the vagina.
 * The endocervical canal is lined by a single layer of tall columnar mucus-secreting cells.
-* Where the cervix is exposed to the vagina(the ectocervix), it is lined by thick stratified squamous epithelium.
+* Where the cervix is exposed to the vagina (the ectocervix), it is lined by thick stratified squamous epithelium.
 ** Cells of the ectocervix often have clear cytoplasm due to their high glycogen content.
 * The junction between the vaginal and endocervical epithelium is abrupt, normally located at the external os.  This is the point where the endocervical canal opens into the vagina.