Difference between revisions of "Corpus Luteum - Anatomy & Physiology"
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== The Corpus Luteum == | == The Corpus Luteum == | ||
− | * When the dominant antral [[ | + | * When the dominant antral [[Follicles_- Anatomy & Physiology|follicle]] ovulates, slight localised haemorrhage occurs at the site of ovulation and fills the former cavity. |
* The small amount of bloody tissue can be observed by the naked eye. | * The small amount of bloody tissue can be observed by the naked eye. | ||
* Loss of fluid from the antral cavity causes the follicle to collapse into many folds. | * Loss of fluid from the antral cavity causes the follicle to collapse into many folds. | ||
− | * As a result, some granulosal and thecal layers are pushed into the apex of the ruptured [[ | + | * As a result, some granulosal and thecal layers are pushed into the apex of the ruptured [[Follicles_- Anatomy & Physiology|follicle]]. |
* This protrusion of tissue and ruptured blood vessels forms a structure known as the '''[[Corpus Haemorrhagicum - Anatomy & Physiology|Corpus Haemorrhagicum]]'''. | * This protrusion of tissue and ruptured blood vessels forms a structure known as the '''[[Corpus Haemorrhagicum - Anatomy & Physiology|Corpus Haemorrhagicum]]'''. | ||
* Following this, the theca interna and granulosa cells differentiate into large and small luteal cells. | * Following this, the theca interna and granulosa cells differentiate into large and small luteal cells. |
Revision as of 18:44, 1 December 2010
This article is still under construction. |
The Corpus Luteum
- When the dominant antral follicle ovulates, slight localised haemorrhage occurs at the site of ovulation and fills the former cavity.
- The small amount of bloody tissue can be observed by the naked eye.
- Loss of fluid from the antral cavity causes the follicle to collapse into many folds.
- As a result, some granulosal and thecal layers are pushed into the apex of the ruptured follicle.
- This protrusion of tissue and ruptured blood vessels forms a structure known as the Corpus Haemorrhagicum.
- Following this, the theca interna and granulosa cells differentiate into large and small luteal cells.
- Luteal cells contain increased quantities of lipid droplets and the pigment 'lutein'.
- As the blood is resorbed, a solid Corpus Luteum is formed by proliferation of granulosa and theca intera cells as well as blood vessels. This remains on the surface of the ovary.
- In the non-pregnant animal, corpora lutea are transient structures.
- Cyclic corpora lutea undergo proliferation and vascularisation directly after ovulation.
- The corpora lutea then regress and degenerate into a connective tissue scar, the Corpus Albicans.
- If the ovum is fertilised, the corpus luteum remains fully developed and active throughout at least part of the pregnancy.
- Corpora lutea produce progesterone.
- Progesterone prepares and maintains the uterus for implantation of the fertilised ovum.
- The number of corpora lutea formed are directly related to the number of oocytes released.
Control of Progesterone Biosynthesis in the Corpus Luteum
- In most species, luteinization and progesterone synthesis is regulated principally by luteinising hormone (LH) in the non-fertile cycle.
- Further conversion to oestradiol is prevented.