2011 Lab 8

From Embryology
2011 Lab 8: Introduction | Sex Determination | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Quiz | Online Assessment

Urogenital Development

This practical will introduce the topic of urogenital differentiation during development through a series of online resource pages.

Aim: This practical is an introduction to the earliest events in Sexual Differentiation.

Key Concepts: Intermediate mesoderm, primordial germ cells, renal development, bladder development, gonad, internal genitalia, external genitalia, ovary, testes, puberty, hormonal changes, gametogenesis, abnormalities.

Background

Historic-testis.jpg

Historic-ovary.jpg

Historic Gonad Images

Two key systems, neural and reproductive, develop over an extended period from the early embryo to puberty and the emerging adult. The genital system is closely linked developmentally to the urinary system, often called the urogenital system. This practical will therefore cover early development of both system.

In understanding embryonic sexual development, think of a cascade of sequence dependent events that transform indifferent gonads, internal and external genitalia into distinct male and female structures.

The process begins with gonad differentiation, which itself is tied developmentally back at the initial event of fertilization and the presence of either a Y or X chromosome in the sperm.

The endpoint of development could be considered the post-puberty active reproductive system. Interestingly, recent research is pointing to a link between neural and reproductive systems in how male and female brains may differentially develop under the influence of sex hormones and perhaps even the sex chromosomes.


  • There are 6 pages to work through in today's practical class, listed at the top and bottom of each page.
  • Additional information sections are not part of the practical class content.

Urogenital Timeline

  • 24 days - intermediate mesoderm, pronephros primordial
  • 28 days - mesonephros and mesonephric duct
  • 35 days - uteric bud, metanephros, urogenital ridge
  • 42 days - cloacal divison, gonadal primordium (indifferent)
  • 49 days - paramesonephric duct, gonadal differentiation
  • 56 days - paramesonephric duct fusion (female)
  • 100 days - primary follicles (ovary)

Textbooks

The Developing Human, 8th edn.jpg Moore, K.L. & Persuad, T.V.N. (2008). The Developing Human: clinically oriented embryology (8th ed.). Philadelphia: Saunders.

The following chapter links only work with a UNSW connection and can also be accessed through this UNSW Library connection.

Larsen's human embryology 4th edn.jpg Schoenwolf, G.C., Bleyl, S.B., Brauer, P.R. and Francis-West, P.H. (2009). Larsen’s Human Embryology (4th ed.). New York; Edinburgh: Churchill Livingstone.

The following chapter links only work with a UNSW connection and can also be accessed through this UNSW Library connection.

Logo.png Hill, M.A. (2011) UNSW Embryology (11th ed.). Sydney:UNSW.
Genital Links: genital | Lecture - Medicine | Lecture - Science | Lecture Movie | Medicine - Practical | primordial germ cell | meiosis | endocrine gonad‎ | Genital Movies | genital abnormalities | Assisted Reproductive Technology | puberty | Category:Genital
Female | X | X inactivation | ovary | corpus luteum | oocyte | uterus | vagina | reproductive cycles | menstrual cycle | Category:Female
Male | Y | SRY | testis | spermatozoa | ductus deferens | penis | prostate | Category:Male
Historic Embryology - Genital 
General: 1901 Urinogenital Tract | 1902 The Uro-Genital System | 1904 Ovary and Testis | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1921 Urogenital Development | 1921 External Genital | 1942 Sex Cords | 1953 Germ Cells | Historic Embryology Papers | Historic Disclaimer
Female: 1904 Ovary and Testis | 1904 Hymen | 1912 Urinogenital Organ Development | 1914 External Genitalia | 1914 Female | 1921 External Genital | 1927 Female Foetus 15 cm | 1927 Vagina | 1932 Postnatal Ovary
Male: 1887-88 Testis | 1904 Ovary and Testis | 1904 Leydig Cells | 1906 Testis vascular | 1909 Prostate | 1912 Prostate | 1914 External Genitalia | 1915 Cowper’s and Bartholin’s Glands | 1920 Wolffian tubules | 1935 Prepuce | 1935 Wolffian Duct | 1942 Sex Cords | 1943 Testes Descent | Historic Embryology Papers | Historic Disclaimer
2011 Lab 8: Introduction | Sex Determination | Early Embryo | Late Embryo | Fetal | Postnatal | Abnormalities | Quiz | Online Assessment

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2024, March 19) Embryology 2011 Lab 8. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/2011_Lab_8

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