Changes

==Introduction==

==Introduction==

The ovary is the female Gonad homologous to the male Testes. It is usually a paired organ in domestic species, but in the bird only the left Ovary is present.  The structures found within the ovary are undergoing constant changes throughout the oestrus cycle from the [[The Ovary_-_Follicles_- Anatomy & Physiology|Follicles]] containing [[The Ovary_-_Oocytes_-_Anatomy_&_Physiology|Oocytes]], to the formation of [[Corpus Haemorrhagicum - Anatomy & Physiology|Corpus Haemorrhagicum]], [[The_Ovary_-_Corpus_Luteum_-_Anatomy_&_Physiology|Corpus Luteum]], and finally [[The_Ovary_-_Corpus_Luteum_-_Anatomy_&_Physiology|Corpus Albicans]]. Ovaries are ellipsoidal in shape with an irregular surface due to the projection of dominant follicles and corpora lutea. These irregularities are absent in the mare due to the cortex and medulla being reversed with ovulation only occuring from the ovulation fossa. They are greatest in [[Gestation_-Litter Sizes_- Anatomy & Physiology|Polytocious]] animals such as the sow due to many dominant follicles, and so corpora lutea, developing at once.

The ovary is the female Gonad homologous to the male Testes. It is usually a paired organ in domestic species, but in the bird only the left Ovary is present.  The structures found within the ovary are undergoing constant changes throughout the oestrus cycle from the [[Follicles_- Anatomy & Physiology|Follicles]] containing [[Oogenesis - Anatomy & Physiology|Oocytes]], to the formation of [[Corpus Haemorrhagicum - Anatomy & Physiology|Corpus Haemorrhagicum]], [[Corpus Luteum - Anatomy & Physiology|Corpus Luteum]], and finally [[Corpus_Luteum_-_Anatomy_&_Physiology|Corpus Albicans]]. Ovaries are ellipsoidal in shape with an irregular surface due to the projection of dominant follicles and corpora lutea. These irregularities are absent in the mare due to the cortex and medulla being reversed with ovulation only occuring from the ovulation fossa. They are greatest in [[Litter Sizes - Anatomy & Physiology|Polytocious]] animals such as the sow due to many dominant follicles, and so corpora lutea, developing at once.

==Anatomical Location==

==Anatomical Location==

* In the '''dog and cat''', ovaries do not migrate in development.  They remain in the dorsal part of the abdomen, caudal to the [[Urinary_System_- Anatomy & Physiology#The_Kidney|kidneys]] at the tip of the [[Uterus - Anatomy & Physiology|uterine horns]].

* In the '''dog and cat''', ovaries do not migrate in development.  They remain in the dorsal part of the abdomen, caudal to the [[Urinary System Overview - Anatomy & Physiology#The_Kidney|kidneys]] at the tip of the [[Uterus - Anatomy & Physiology|uterine horns]].

* In other domestic species, the ovaries migrate during development.   

* In other domestic species, the ovaries migrate during development.   

* The greatest degree of migration occurs in '''ruminants'''.  Here, the ovaries come to lie close to the ventral abdominal wall, cranial to the pelvic inlet.

* The greatest degree of migration occurs in '''ruminants'''.  Here, the ovaries come to lie close to the ventral abdominal wall, cranial to the pelvic inlet.

* In all domestic species except the horse, ovaries are ellipsoidal in shape and their surface has large follicles and corpora lutea.

* In all domestic species except the horse, ovaries are ellipsoidal in shape and their surface has large follicles and corpora lutea.

* The ovaries of the mare are kidney shaped and the surface is smooth.

* The ovaries of the mare are kidney shaped and the surface is smooth.

*The ovaries are suspended in the abdominal cavity by the Mesovarium of the [[The Uterus_-_The Broad Ligament_- Anatomy & Physiology|Broad Ligament]].

*The ovaries are suspended in the abdominal cavity by the Mesovarium of the [[Broad Ligament - Anatomy & Physiology|Broad Ligament]].

==Structure==

==Structure==

*Contains:

*Contains:

** [[The Ovary_-_Follicles_- Anatomy & Physiology|Follicles]] in various stages of development  

** [[Follicles_- Anatomy & Physiology|Follicles]] in various stages of development  

** [[The Ovary_-_Corpus Luteum_- Anatomy & Physiology|Corpus Luteum]] (includes Corpus Haemorrhagicum and Corpus Albicans)

** [[Corpus Luteum_- Anatomy & Physiology|Corpus Luteum]] (includes Corpus Haemorrhagicum and Corpus Albicans)

=== Ovarian Medulla ===

=== Ovarian Medulla ===

==== The Mare ====

==== The Mare ====

[[Image:Mare Ovary.jpg|thumb|right|150px|The Ovaries of a Mare showing the Ovulation Fossa- Courtesy of A.Crook, Copyright RVC 2008]]

[[Image:Mare Ovary.jpg|thumb|right|200px|The Ovaries of a Mare showing the Ovulation Fossa- Courtesy of A.Crook, Copyright RVC 2008]]

* The structure of the ovary is reversed.

* The structure of the ovary is reversed.

* The cortex is in the centre, follicles develop here.

* The cortex is in the centre, follicles develop here.

==Histology==

==Histology==

[[Image:Ovary low magnification.jpg|thumb|right|150px|Histological Section of a Rabbit Ovary under Low Power- Courtesy of J.Bredl, Copyright RVC 2008]]

[[Image:Ovary low magnification.jpg|thumb|right|200px|Histological Section of a Rabbit Ovary under Low Power- Courtesy of J.Bredl, Copyright RVC 2008]]

=== Stroma ===

=== Stroma ===

* Highly vascular

* Highly vascular

* Contains hilus cells, which are similar to the Leydig cells of the [[Male_Reproductive_Tract_-The_Testes_and_Epididymis_- Anatomy & Physiology#The_Testes|testes]].

* Contains hilus cells, which are similar to the Leydig cells of the [[Testes and Epididymis - Anatomy & Physiology#The_Testes|testes]].

==Vasculature==

==Vasculature==

=== Arterial Supply ===

=== Arterial Supply ===

* The ovarian artery (a branch of the Aorta) and ovarian branches of the Uterine artery form anastomoses in the mesovarium and the [[The_Uterus_-_The_Broad_Ligament_- Anatomy & Physiology|broad ligament]].

* The ovarian artery (a branch of the Aorta) and ovarian branches of the Uterine artery form anastomoses in the mesovarium and the [[Broad Ligament - Anatomy & Physiology|broad ligament]].

* From this arterial plexus ~10 coiled Helicine arteries enter the hilus of the ovary.

* From this arterial plexus ~10 coiled Helicine arteries enter the hilus of the ovary.

* Smaller branches form a plexus at the corticomedullary junction, giving rise to straight Cortical arterioles, which radiate into the cortex.

* Smaller branches form a plexus at the corticomedullary junction, giving rise to straight Cortical arterioles, which radiate into the cortex.

==Function==  

==Function==  

It has two main functions:

It has two main functions:

* Producing the female gametes [[The_Ovary_-_Oogenesis_- Anatomy & Physiology|oocytes]] via Gametogenesis.

* Producing the female gametes [[Oogenesis - Anatomy & Physiology|oocytes]] via Gametogenesis.

* Producing the reproductive hormones Oestrogens and Progesterone, an [[Endocrine_System_- Anatomy & Physiology|endocrine function]].

* Producing the reproductive hormones Oestrogens and Progesterone, an [[Endocrine_System_- Anatomy & Physiology|endocrine function]].

=== [[Ovulation - Anatomy & Physiology|Ovulation]] ===

=== [[Ovulation - Anatomy & Physiology|Ovulation]] ===

=== [[Luteum Formation - Anatomy & Physiology|Corpus Luteum Formation]] ===

=== [[Corpus Luteum Formation - Anatomy & Physiology|Corpus Luteum Formation]] ===

 

=== [[Corpus Luteum Regression- Anatomy & Physiology|Corpus Luteum Regression]] ===

[[Category:Female Reproduction]]

[[Category:Female Reproduction]]