Endocrine - Gonad Development: Difference between revisions

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==Androgen and Digit ratio (2D:4D)==
==Androgen and Digit ratio (2D:4D)==
 
[[File:Finger_length_ratio_-_2D4D.jpg|thumb|Androgen and Digit ratio (2D:4D]]
The ratio of 2nd and 4th finger (D, digit) length. This ratio has been suggested to relate to high fetal [[T#testosterone|testosterone]] concentration (males have lower 2D:4D than females) and has been shown for several species.<ref><pubmed>16504142</pubmed></ref> Although a study in mice has not shown the same correlation.<ref><pubmed>19495421</pubmed></ref> There have been some suggestions that the ratio may also be an indicator of various neurological abnormalities.
The ratio of 2nd and 4th finger (D, digit) length. This ratio has been suggested to relate to high fetal [[T#testosterone|testosterone]] concentration (males have lower 2D:4D than females) and has been shown for several species.<ref><pubmed>16504142</pubmed></ref> Although a study in mice has not shown the same correlation.<ref><pubmed>19495421</pubmed></ref> There have been some suggestions that the ratio may also be an indicator of various neurological abnormalities.


'''To measure (2D:4D)''' - using your right hand palm up, measure the index finger (2) and ring finger (4) length from palm to tip. Dividing the index finger by the ring finger gives the 2D:4D ratio, average women ratio is 1, average men is 0.98.  
'''To measure (2D:4D)''' - using your right hand palm up, measure the index finger (2) and ring finger (4) length from palm to tip. Dividing the index finger by the ring finger gives the 2D:4D ratio, average women ratio is 1, average men is 0.98.
 


==Adult Histology==
==Adult Histology==

Revision as of 19:39, 4 July 2011

Notice - Mark Hill
Currently this page is only a template and will be updated (this notice removed when completed).

Introduction

Female HPG axis

The term gonad refers to both the female ovary and the male testis, which have their own topic pages.

This section of notes refers only to the development of the gonad as an endocrine organ. A detailed description of the gonad development is covered in both Ovary Development and Testis Development.

Embryonically, initial endocrine development of the testis is required for development of both the internal genital tract and the external genitalia.

Postnatally, the gonads are part of an integrated Hypothalamus-Pituitary-Gonad (HPG) axis.

Endocrine Links: Introduction | BGD Lecture | Science Lecture | Lecture Movie | pineal | hypothalamus‎ | pituitary | thyroid | parathyroid | thymus | pancreas | adrenal | endocrine gonad‎ | endocrine placenta | other tissues | Stage 22 | endocrine abnormalities | Hormones | Category:Endocrine
Historic Embryology - Endocrine  
1903 Islets of Langerhans | 1903 Pig Adrenal | 1904 interstitial Cells | 1908 Pancreas Different Species | 1908 Pituitary | 1908 Pituitary histology | 1911 Rathke's pouch | 1912 Suprarenal Bodies | 1914 Suprarenal Organs | 1915 Pharynx | 1916 Thyroid | 1918 Rabbit Hypophysis | 1920 Adrenal | 1935 Mammalian Hypophysis | 1926 Human Hypophysis | 1927 Adrenal | 1927 Hypophyseal fossa | 1930 Adrenal | 1932 Pineal Gland and Cysts | 1935 Hypophysis | 1935 Pineal | 1937 Pineal | 1935 Parathyroid | 1940 Adrenal | 1941 Thyroid | 1950 Thyroid Parathyroid Thymus | 1957 Adrenal

| Lecture - Genital Development

HPG Axis - Endocrinology - Simplified diagram of the actions of gonadotrophins

Gonad Development

  • mesoderm - mesothelium and underlying mesenchyme, primordial germ cells
  • Gonadal ridge - mesothelium thickening, medial mesonephros
  • Primordial Germ cells - yolk sac, to mesentery of hindgut, to genital ridge of developing kidney

Differentiation

  • testis-determining factor (TDF) from Y chromosome: presence (testes), absence (ovaries)

Testis

  • 8 Weeks, mesenchyme, interstitial cells (of Leydig) secrete testosterone, androstenedione
  • 8 to 12 Weeks - hCG stimulates testosterone production
  • Sustentacular cells - produce anti-mullerian hormone to puberty

Ovary

  • X chromosome genes regulate ovary development

Steroidogenesis

Steroidogenesis

Androgen and Digit ratio (2D:4D)

Androgen and Digit ratio (2D:4D

The ratio of 2nd and 4th finger (D, digit) length. This ratio has been suggested to relate to high fetal testosterone concentration (males have lower 2D:4D than females) and has been shown for several species.[1] Although a study in mice has not shown the same correlation.[2] There have been some suggestions that the ratio may also be an indicator of various neurological abnormalities.

To measure (2D:4D) - using your right hand palm up, measure the index finger (2) and ring finger (4) length from palm to tip. Dividing the index finger by the ring finger gives the 2D:4D ratio, average women ratio is 1, average men is 0.98.

Adult Histology

References

  1. <pubmed>16504142</pubmed>
  2. <pubmed>19495421</pubmed>


Reviews

Articles

Search PubMed

Search Pubmed: endocrine gonad development

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Cite this page: Hill, M.A. (2024, March 29) Embryology Endocrine - Gonad Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Endocrine_-_Gonad_Development

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G