List_of_homologues_of_the_human_reproductive_system

List of related male and female reproductive organs

List of related male and female reproductive organs

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This list of related male and female reproductive organs shows how the male and female reproductive organs and the development of the reproductive system are related, sharing a common developmental path. This makes them biological homologues. These organs differentiate into the respective sex organs in males and females.

Tail end of human embryo, from eight and a half to nine weeks old.
1 - 7: Homologous male and female pelvic organs.
Diagrams that show the development of male and female organs from a common precursor. Sperm ducts and fallopian tubes are not homologous, as the sperm ducts originate from the Wolffian ducts, whereas the fallopian tubes originate from the Müllerian ducts.

List

Internal organs

More information Embryological precursor, Female ...
Stages in the development of the external sexual organs in the male and female:
  • A: Undifferentiated
  • B: Female
  • C: Male
  • D: Female
  • E: Male
  • F: Female
Development of external genitalia

External organs

The external genitalia of both males and females have similar origins. They arise from the genital tubercle that forms anterior to the cloacal folds (proliferating mesenchymal cells around the cloacal membrane). The caudal aspect of the cloacal folds further subdivides into the posterior anal folds and the anterior urethral folds. Bilateral to the urethral fold, genital swellings become prominent. These structures are the future scrotum and labia majora in males and females, respectively.

The genital tubercles of an eight-week-old embryo of either sex are identical. They both have a glans area, which will go on to form the clitoral glans (females) or penile glans (males), a urogenital fold and groove, and an anal tubercle. At around ten weeks, the external genitalia are still similar. At the base of the glans, there is a groove known as the coronal sulcus or corona glandis. It is the site of attachment of the future prepuce. Just anterior to the anal tubercle, the caudal end of the left and right urethral folds fuse to form the urethral raphe. The lateral part of the genital tubercle (called the lateral tubercle) grows longitudinally and is about the same length in either sex.

Human physiology

The male external genitalia include the penis and the scrotum. The female external genitalia include the clitoris, the labia, and the vaginal opening, which are collectively called the vulva. External genitalia vary widely in external appearance among different people.

One difference between the glans penis and the glans clitoridis is that the glans clitoridis packs nerve endings into a volume only about one-tenth the size of the glans penis. Therefore, the glans clitoridis has greater variability in cutaneous corpuscular receptor density (1-14 per 100× high-powered field) compared with the glans penis (1-3 per 100× high-power field). Touch for touch, this concentration of nerves makes the glans clitoridis more sensitive than the glans penis. As a result, many women can feel discomfort or pain with anything more than a gentle touch.[3]


References

  1. Cai Y (2009). "Revisiting old vaginal topics: conversion of the Müllerian vagina and origin of the "sinus" vagina". Int J Dev Biol. 53 (7): 925–34. doi:10.1387/ijdb.082846yc. PMID 19598112.
  2. Arulkumaran, Sabaratnam; Ledger, William; Doumouchtsis, Stergios; Denny, Lynette (December 2019). Oxford Textbook of Obstetrics and Gynaecology. ISBN 978-0-19-876636-0.
  3. Cheryl Shih, Christopher J. Cold, and Claire C. Yang. "Cutaneous Corpuscular Receptors of the Human Glans Clitoris: Descriptive Characteristics and Comparison with the Glans Penis", Journal of Sexual Medicine, Elsevier, July 2013.

Public domain This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)


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