Retractor muscle of the penis
Anatomical feature of male carnivoran, marsupial and ungulate mammals
From Wikipedia, the free encyclopedia
In some animals, the male penis possesses a muscle enabling retraction into the prepuce.[1]
In particular animals
The retractor penis muscle occurs in marsupials and carnivorans, but it is absent in humans.[2] A stag's penis forms an S-shaped curve when it is not erect, and is retracted into its preputial sheath by the retractor penis muscle.[3]
In Tandonia, the retractor penis inserts at the boundary between the penis and epiphallus.[4]
In stallions, the retractor penis muscle is relatively underdeveloped.[5] The retractor muscle contracts to retract the penis into the sheath and relaxes to allow the penis to extend from the sheath.[6]
In bulls, protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure.[5]
