Difference between revisions of "Cervix - Anatomy & Physiology"

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|linkpage =Reproductive System - Anatomy & Physiology
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|linktext =Reproductive System
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|maplink = Reproductive System (Content Map) - Anatomy & Physiology
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|pagetype =Anatomy
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|sublink1=Reproductive System - Anatomy & Physiology#Female Reproductive Tract
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|subtext1=FEMALE REPRODUCTIVE TRACT
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==Introduction==
 
==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==
  
* The lumen of the cervix is the cervical canal.
+
* Thick-walled
* The canal is formed by, and often almost occluded by mucosal folds.
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* 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
 
** 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 ===
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* 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 ===
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* Less mucous secretion
 
* Less mucous secretion
 
* Multiple folds
 
* Multiple folds
* Cervical folds form rings (cervical rings)  
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* 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 and Vestibule - Anatomy & Physiology|vagina]] (fornix vagina)
+
* Many longitudinal folds of mucosa that protrude into the 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
 +
* A portion protrudes into the cranial vagina (fornix vagina).
  
 
=== 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 - Anatomy & Physiology|uterus]] or [[Vagina and Vestibule - Anatomy & Physiology|vagina]]
+
* Thick walled compared to the uterus or vagina
 
* Single fold
 
* Single fold
 
* Smooth surface
 
* Smooth surface
  
==Histology==
+
==Function==
 +
 
 +
* 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.
  
[[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]] ]]
+
==Anatomical Boundaries==
[[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]] ]]
+
*Located between the Uterus and the Vagina.
  
 +
==Histology==
  
* 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.
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*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).
  
==Function==
+
==Links==
 
 
* 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.
 
<br>
 
 
 
 
 
{{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]]
 

Revision as of 11:34, 9 September 2008

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()Map REPRODUCTIVE SYSTEM (Map)
FEMALE REPRODUCTIVE TRACT



Introduction

Structure

  • 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


Cow and Ewe

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

Sow

  • Less mucous secretion
  • Multiple folds
  • Cervical folds form rings (cervical rings)

Mare

  • Low volume mucous secretion
  • Multiple folds
  • Many longitudinal folds of mucosa that protrude into the vagina (fornix vagina)
  • Soft during oestrus

Bitch

  • Single fold
  • Relatively smooth surface
  • A portion protrudes into the cranial vagina (fornix vagina).

Queen

  • Small
  • Thick walled compared to the uterus or vagina
  • Single fold
  • Smooth surface

Function

  • 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.

Anatomical Boundaries

  • Located between the Uterus and the Vagina.

Histology

  • 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.

Vascularisation

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

Links