The baculum (also penis bone, penile bone or os penis) is a bone found in the penis of most mammals. It is absent in humans, equidae, marsupials, lagomorphs, and hyaenas, amongst others. It is used for copulation and varies in size and shape by species. Its characteristics are sometimes used to differentiate between similar species. The word originally meant "stick" or "staff" in Latin.

In humans, the rigidity of the erection is provided entirely through blood pressure in the corpus cavernosum.

Examples of animals with a penile bone include rats, dogs and walruses.

Biblical Note

In the Bible's Book of Genesis, Adam's rib is removed to create Eve. Biblical Hebrew does not have a word for penis. Some scholars (Gilbert and Zevit 2001) have suggested this story is an explanatory myth to explain the absence of a baculum in the male human, rather than a missing rib (in light of the fact that men and women have the same number of ribs).

See also

• Oosik

External links

• Beresford WA, Burkart S. The penile bone and anterior process of the rat in scanning electron microscopy. J Anat. 1977 Dec;124(3):589-97.
• Some pictures of real and replica penis bone samples
• The San Diego Zoo's Conservation and research for endangered species projects. 'What is the significance of the baculum in animals?'
• The baculum as "Adam's rib"

References

Animal anatomy | Penis

Penisknochen | Baculum | Osso penico | Penisbot | Kość prącia | Penisben