UNSW Embryology

Corpus Luteum

© Dr Mark Hill (2011)

Acknowledgements

Introduction

At the midpoint of the menstrual cycle an increase of pituitary gonadotrophins (LH, FSH) leads to not only follicle rupture and ovulation but also conversion of the remaining follicular structure into the corpus luteum (Latin, corpus = body, luteum = yellow).

Historic drawing of the ovary with corpus luteum	Whole ovary with corpus albicans on left

If fertilization and implantation occurs, the follicle will be maintained and continue as the corpus luteum, "yellow body". It has this histological yellow appearance as it is the structure within the ovary synthesizing hormones to maintain the pregnancy.

If fertilization and implantation does not occur, the corpus luteum will degenerate into the corpus albicans, "white body".

Page Links: Introduction | Some Recent Findings | Follicle Structure | Corpus Luteum | Corpus_Albicans | Hypothalamus Pituitary Gonad Axis | Ovarian Angiogenesis | References | Glossary

Other Pages: Ovary development is covered on Development of the Reproductive System | Female

Some Recent Findings

Stocco C, Telleria C, Gibori G. The molecular control of corpus luteum formation, function, and regression. Endocr Rev. 2007 Feb;28(1):117-49.

"The corpus luteum (CL) is one of the few endocrine glands that forms from the remains of another organ and whose function and survival are limited in scope and time. The CL is the site of rapid remodeling, growth, differentiation, and death of cells originating from granulosa, theca, capillaries, and fibroblasts."

Bachelot A, Binart N. Corpus luteum development: lessons from genetic models in mice. Curr Top Dev Biol. 2005;68:49-84. Review.

"The life span and function of the corpus luteum is regulated by complex interactions between stimulatory (luteotrophic) and inhibitory (luteolytic) mediators. ... In rodents, prolactin is the major luteotrophic hormone by maintaining the structural and functional integrity of the corpus luteum for several days after mating. Other factors involved in steroidogenesis, control of cell cycle, apoptosis, and tissue remodeling have been shown to play a role in corpus luteum development and maintenance. Especially, PGF2alpha seems to be the most potent luteolytic hormone."

Follicle Structure

Granulosa Cells

A specific cell type that proliferates in association with the oocyte within the developing follicles of the ovary. These cells form the follicle stratum granulosa and are also given specific names based upon their position within the follicle.

• The membrana granulosa cells sit on the follicular basal lamina and line the antrum as a stratified epitelium. Following ovulation, these granulosa cells contribute to corpus luteum.
• The cumulus oophorus is a column of granulosa cells that attaches the oocyte to the follicle wall. At ovulation, this column of cells is broken or separates to release the oocyte from its follicle attachment.
• The corona radiata are the granulosa cells that directly surround the oocyte, and are released along with it at ovulation. Following ovulation, the corona radiata provide physical protection to the oocyte and are the initial structural barrier that spermatazoa must penetrate during fertilization.

Theca Interna

The ovarian follicle stromal cells forming the inner layer of the theca folliculi surrounding the developing follicle within the ovary. This vascularized layer of cells respond to leutenizing hormone (LH) synthesizing and secreting androgens which are processed into estrogen. Theca cells do not begin secreting estrogen until puberty.

Theca Externa

The ovarian follicle stromal cells forming the outer layer of the theca folliculi surrounding the developing follicle within the ovary. Consisting of connective tissue cells, smooth muscle and collagen fibers.

Corpus Luteum

(Images: Lutz Slomianka, UWA Blue Histology)

If fertilization and implantation occurs, the follicle will develop into the corpus luteum, "yellow body". The name is based historically upon its histological appearance, the yellow colour due to the high level of steoidogenesis occuring to support the pregnancy and prevent menses. The main steroidal hormone produced by the corpus luteum is progesterone.

Links: UWA Blue Histology - Corpus Luteum

Corpus Albicans

If fertilization and implantation does not occur, the corpus luteum will degenerate into the corpus albicans, "white body" (plural, corpora albicantia). The name is based historically upon its histological appearance, the white colour due to the lack of steoidogenesis occuring and therefore menses will proceed.

References: Focchi GR, Simoes Mde J, Baracat EC, de Lima GR, Evencio Neto J. Ultrastructural aspects of the remodeling process of the Corpus albicans in the recent postmenopausal period. Sao Paulo Med J. 1996 May-Jun;114(3):1173-6.

Hypothalamus - Pituitary - Gonad (HPG) Axis

The diagram shows the hormonal regulation pathway from the brain to the ovary and subsequent impact on uterine changes during the menstral cycle. (LHRH = Luteinizing Hormone-Releasing Hormone) Gonadotropin-releasing hormone (GnRH) is a decapeptide (10 amino acid) with a short half life (<15 minutes).

(Image: NIAAA Emanuele, M.A. etal)

A similar axis is also found for regulation of the male gonad.

Ovary Whole (low power)

Montage from separate low power images showing the whole ovary (cat).

Features:

• cortex (with many small primordial follicles)
• medullary region (with blood vessels)
• preantral and antral follicles
• mesovarium
• oviduct- epithelium, mucosal folds, muscularis (thick circular, thin outer longitudinal)

Ovarian Angiogenesis

• The female reproductive system is unique in that this is the only site in the uninjured adult body where angiogenesis (the formation of new blood vessels) occurs in a repetitive cyclic fashion.
  • in the ovary during follicular development and corpus luteum formation.
  • in the endometrium during proliferative phase of menstrual cycle.
• After formation of the follicular antrum, the follicle acquires a vascular sheath in the theca layer.
• Establishment of the vascular sheath, particularly the expansion of the inner capillary plexus of the theca interna, co-incides with a period of rapid growth and differentiation of the follicle.
• The granulosa and theca cells of ovarian follicles are sources of angiogenic activity, which appear to be under the control of gonadotropins.
• At the time of follicular rupture, vessels of the theca begin to sprout and penetrate the membrana granulosa
• They anastomose to form a dense network, ultimately bringing each lutein cell into close approximation to the vascular system.
• Rates of follicular and luteal blood flow are among the highest in the body
  • follicular 5-10 ml/min/g and luteal 10-30 ml/min/g
  • compared to normal renal flow of approximately 4-8 ml/min/g
    • these rates determined from ultrasound data
    • colour Doppler imaging (CDI), colour power angiography (CPA) and three-dimensional ultrasound (3D-US)
• Systemic concentrations of ovarian steroids regulate endometrial growth and development
• The rate of blood flow to uterine tissues also varies throughout the menstrual cycle and during the pregnancy.

(Data from: Advances in Ultrasound Assessment in the Establishment and Development of Pregnancy. Sladkevicius P & Campbell S. British Medical Bulletin 2000; 56: 691-703)

Histology- Female Genital System

Back to Urogenital Notes 1 | 2 | 3 | 4 | Page 5 (histo)

Virtual Slidebox of Histology Female genital tract

Blue Histology Female Reproductive System

• UNSW School of Pathology
  • Specimen 618.1 - Ovarian Tumour
• Loyola University Medical Education Network (LUMEN- Histology)
  • Part 21: Female Reproducive Tract - Ovary, Oviduct, and Uterus
  • Part 22: Female Reproductive Tract - Cervix, Vagina, Umbilical Cord, Placenta, and Mammary Gland
• University of WA- Department of Anatomy and Human Biology (Histology Notes)
  • HA235 - Histology - Female Reproductive System
• University of Kansas Department of Anatomy and Cell Biology (JayDoc HistoWeb)
  • Female Reproductive System
• The College of Medicine at the University of Florida (Histology Tutorial)
  • Laboratory 22: Female Reproductive System I
  • Laboratory 23: Female Reproductive System II
  • Female Reproductive System Quiz

References

Links: Journals | Online Textbooks | Search Textbooks | Reviews | Search PubMed | Glossary

Online Textbooks

Molecular Biology of the Cell (4th Edn) Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter. New York: Garland Publishing; 2002. Image: The stages of oogenesis | Eggs Develop in Stages |

Developmental Biology (6th Edn) Gilbert, Scott F. Sunderland (MA): Sinauer Associates, Inc.; c2000. oogenesis | Image: The ovarian follicle of mammals

Search NLM Online Textbooks- "oogenesis" : Molecular Biology of the Cell | Molecular Cell Biology | The Cell- A molecular Approach

Reviews

Stocco C, Telleria C, Gibori G. The molecular control of corpus luteum formation, function, and regression. Endocr Rev. 2007 Feb;28(1):117-49.

Bachelot A, Binart N. Corpus luteum development: lessons from genetic models in mice. Curr Top Dev Biol. 2005;68:49-84.

Sasano H, Suzuki T. Localization of steroidogenesis and steroid receptors in human corpus luteum. Classification of human corpus luteum (CL) into estrogen-producing degenerating CL, and nonsteroid-producing degenerating CL. Semin Reprod Endocrinol. 1997;15(4):345-51.

Focchi GR, Simoes Mde J, Baracat EC, de Lima GR, Evencio Neto J. Ultrastructural aspects of the remodeling process of the Corpus albicans in the recent postmenopausal period. Sao Paulo Med J. 1996 May-Jun;114(3):1173-6.

Sawyer HR. Structural and functional properties of the corpus luteum of pregnancy. J Reprod Fertil Suppl. 1995;49:97-110.

Articles

Search PubMed

Search April 2007 "corpus luteum" 12,349 reference articles of which 976 were reviews; "corpus albicans" 64 reference articles of which 3 were reviews

Search PubMed: corpus luteum | corpus albicans | follicle atresia

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