Body orifice

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, drinking, 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
• The urinary meatus, for urination in males and females and ejaculation in males
• In females, the vagina, for menstruation, copulation and birth
• The nipple orifices

Other animals may have some other body orifices:

• The cloaca in birds, reptiles, amphibians, and a few mammals
• The siphon in mollusks, arthropods, and some other animals

Internal

Internal orifices include the orifices of the outflow tracts of the heart, between the heart valves.

See also

• Internal urethral orifice
• Mucosa
• Mucocutaneous boundary
• Meatus
• Body cavity

References