Baculum

Not to be confused with Penile spines.

Baculum of a dog's penis; the arrow shows the urethral sulcus, which is the groove in which the urethra lies.
Fossil baculum of a bear (Indarctos) from the Miocene

The baculum (pl.: bacula), also known as the penis bone, penile bone, os penis, os genitale,[1] or os priapi,[2] is a bone in the penis of many placental mammals. It is not present in humans, but is present in the penises of some primates, such as the gorilla and the chimpanzee.[3][4] The baculum arises from primordial cells in soft tissues of the penis, and its formation is largely influenced by androgens.[5] The bone lies above the urethra,[6] and it aids sexual reproduction by maintaining stiffness during sexual penetration. The homologue to the baculum in female mammals is the baubellum (os clitoridis), a bone in the clitoris.[7][8][9]

  1. ^ Cite error: The named reference EvansLahunta2013 was invoked but never defined (see the help page).
  2. ^ Dollé, P.; Izpistia-Belmonte, J.-C.=; Brown, J.M.; Tickle, C.; Duboule, D. (1991). "HOX-4 genes and the morphogenesis of mammalian genitalia" (PDF). Genes & Development. 5 (10): 1767–1776. doi:10.1101/gad.5.10.1767. PMID 1680771. S2CID 6307427. Archived from the original (PDF) on 20 July 2018.
  3. ^ Dixson, Alan F. (26 January 2012). Primate Sexuality: Comparative Studies of the Prosimians, Monkeys, Apes, and Humans. OUP Oxford. ISBN 978-0-19-150342-9. Archived from the original on 31 December 2013. Retrieved 13 February 2018.
  4. ^ Cite error: The named reference patterns was invoked but never defined (see the help page).
  5. ^ Nasoori, Alireza (2020). "Formation, structure, and function of extra-skeletal bones in mammals". Biological Reviews. 95 (4): 986–1019. doi:10.1111/brv.12597. PMID 32338826. S2CID 216556342.
  6. ^ Cite error: The named reference PerrinWursig2009 was invoked but never defined (see the help page).
  7. ^ Best, Troy L.; Granai, Nancy J. (2 December 1994). "Tamius merriami" (PDF). Mammalian Species (476): 1–9. doi:10.2307/3504203. JSTOR 3504203. S2CID 253909941. Archived (PDF) from the original on 23 June 2010. Retrieved 15 January 2010.
  8. ^ Burrows, Harold (1945). Biological Actions of Sex Hormones. Cambridge University Press. p. 264. ISBN 9780521043946. Archived from the original on 21 October 2021. Retrieved 4 August 2012.
  9. ^ Ewer, R. F. (1973). The Carnivores. Cornell University Press. ISBN 978-0-8014-8493-3. Archived from the original on 28 May 2013. Retrieved 16 December 2012.