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Cervix - Anatomy & Physiology (view source)
Revision as of 16:37, 3 January 2023
, 16:37, 3 January 2023no edit summary
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==Introduction==
The cervix can be palpated transrectally and forms a sphincter controlling access to the [[Uterus - Anatomy & Physiology|uterus]].The anatomy of the cervical canal is adapted to suit a particular pattern of reproduction and its composition will alter under the influence of reproductive hormones. Not only does it respond to the fluctuation in oestrodiol during the [[Oestrous Cycle - Anatomy & Physiology|oestrous cycle]], but is responsive to prostaglandins and oxytocin in order to [[Cervical Softening - Anatomy & Physiology|'soften']] for [[:Category:Pregnancy and Parturition|parturition]].
==Structure==
==Structure==
* Thick-walled
* The lumen of the cervix is the cervical canal.
* The canal is formed by, and often almost occluded by mucosal folds.
* Folds surround the lumen
** Single fold and smooth surface in the queen and bitch
** Single fold and smooth surface in the queen and bitch
** Multiple folds protruding into the cervical canal in the cow, ewe, sow and mare
** Multiple folds protruding into the cervical canal in the cow, ewe, sow and mare.
* The cervical canal opens cranially into the body of the [[Uterus - Anatomy & Physiology|uterus]] at the internal uterine ostium.
* The cervical canal opens caudally into the [[Vagina and Vestibule - Anatomy & Physiology|vagina]] at the external uterine ostium.
=== Cow and Ewe ===
=== Cow and Ewe ===
* Multiple folds
* Multiple folds
* Cervical rings form interlocking finger-like projections known as interdigitating prominences.
* Cervical rings form interlocking finger-like projections known as interdigitating prominences.
* Elaborate system of folds and crypts to provide a site of storage where sperm are protected from the spermicidal environment of the vagina and [[Uterus - Anatomy & Physiology|uterus]] in the ewe.
* Allows semen to be ejaculated directly into the [[Uterus - Anatomy & Physiology|uterus]] for rapid transport to the [[Oviduct - Anatomy & Physiology|oviducts]] in the cow.
=== Sow ===
=== Sow ===
* Less mucous secretion
* Less mucous secretion
* Multiple folds
* Multiple folds
* Cervical folds form rings (cervical rings)
* Cervical folds form rings (cervical rings)
* Mounds or cushions known as pulvini interdigitate with each other to close the cervical canal.
* Ensures a tight coupling of the [[Penis - Anatomy & Physiology|penis]] with the cervix to ensure that the large volume of semen produced by the boar is deposited in the [[Uterus - Anatomy & Physiology|uterus]].
=== Mare ===
=== Mare ===
* Simple cervix with the most caudal part bulging into the [[Vagina and Vestibule - Anatomy & Physiology|vagina]] to form a distinct recess (vaginal fornix).
* Low volume mucous secretion
* Low volume mucous secretion
* Multiple folds
* Multiple folds
* Many longitudinal folds of mucosa that protrude into the vagina (fornix vagina)
* Many longitudinal folds of mucosa that protrude into the [[Vagina and Vestibule - Anatomy & Physiology|vagina]] (fornix vagina)
* Soft during oestrus
* Soft during oestrus
=== Bitch ===
=== Bitch ===
* Simple cervix with the most caudal part bulging into the [[Vagina and Vestibule - Anatomy & Physiology|vagina]] to form a distinct recess (vaginal fornix).
* Single fold
* Single fold
* Relatively smooth surface
* Relatively smooth surface
=== Queen ===
=== Queen ===
* External uterine ostium opens on a small hillock projecting into the [[Vagina and Vestibule - Anatomy & Physiology|vagina]].
* Small
* Small
* Thick walled compared to the uterus or vagina
* Thick walled compared to the [[Uterus - Anatomy & Physiology|uterus]] or [[Vagina and Vestibule - Anatomy & Physiology|vagina]]
* Single fold
* Single fold
* Smooth surface
* Smooth surface
==Function==
==Histology==
[[Image:Ewe Cervix.jpg|thumb|right|150px|Histological Section of the Cervix of a Ewe- from the [[Female Reproductive Tract Histology resource|Histology of the female reproductive tract PowerPoint]] ]]
[[Image:Ewe Cervical Lumen.jpg|thumb|right|150px|Histological Section of the Cervical Lumen of a Ewe- from the [[Female Reproductive Tract Histology resource|Histology of the female reproductive tract PowerPoint]] ]]
* The lumen of the cervix is lined by a simple columnar epithelium containing many mucus 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.
* 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.
* 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.
** 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 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.
*Uterine artery off the Internal Iliac artery (External Iliac artery in the Mare).
*Uterine artery off the Internal Iliac artery (External Iliac artery in the Mare).
==Links==
==Function==
* Provides a physical barrier to the uterus therefore preventing abortion due to infection by isolating the foetus from the external environment, closure is via the mucosal folds.
* Cervical mucosa produces a mucous secretion which forms a mucous plug that helps close the cervical canal. This is easily expelled during [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] and parturition.
* 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 - Anatomy & Physiology|fertilisation]] is possible (around [[Ovulation - Anatomy & Physiology|ovulation]]).
* Mucus production for lubrication and to prevent microorganisms from entering the [[Uterus - Anatomy & Physiology|uterus]].
* Remodels itself at the end of gestation to allow birth and to stimulate the development of maternal behaviour.
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{{Template:Learning
|powerpoints = [[Female Reproductive Tract Histology resource|Histology of the female reproductive tract]]
}}
==Webinars==
<rss max="10" highlight="none">https://www.thewebinarvet.com/urogenital-and-reproduction/webinars/feed</rss>
[[Category:Female Reproduction]]
[[Category:Bullet Points]]