Body orifice
Appearance
A body orifice is any opening in the body of an animal.
External
In a typical mammalian body such as the human body, the external body orifices are:
- The nostrils, for breathing and the associated sense of smell
- The mouth, for eating, breathing, and vocalizations such as speech
- The ear canals, for the sense of hearing
- The nasolacrimal ducts, to carry tears from the lacrimal sac into the nasal cavity
- The anus, for defecation
- In males, the urinary meatus, for urination and ejaculation
- In females, the urinary meatus, for urination
- In females, the vagina, for menstruation, sexual intercourse and childbirth
- The nipple orifices
Other animals may have some other body orifices:
- cloaca, in birds, reptiles, amphibians, and some other animals
- siphon in mollusk, arthropods, and some other animals
Internal
Internal orifices include the orifices of the outflow tracts of the heart, between the heart valves.