Difference between revisions of "Cervix - Anatomy & Physiology"

From WikiVet English
Jump to navigation Jump to search
Line 69: Line 69:
  
 
* 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.
 +
* 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==
 
==Vascularisation==

Revision as of 11:34, 9 September 2008

Anatomy and PhysiologyWikiAnt and Phys Banner.png
()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