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The opening between the atrium and the ventricle on each side of the heart.
See also: orifice
1. the entrance or outlet of any body cavity.
2. any foramen, meatus or opening.
The names of most orifices are self-defining, e.g. atrioventricular, preputial. See also ostium.
the opening between the atria and ventricles.
aperture through which the cecum connects with the colon.
the communicating orifice between the ileum and the colon.
slit-like orifice at the ovarian end of the avian oviduct; positioned near the ovary so that it can grasp the newly extruded oocyte.
the orifice between the nasopharynx and oropharynx which is bounded by the palatopharyngeal arches.
the slit-like opening between the maxillary sinus and the middle meatus of the nasal cavity.
large, oval opening at the end of the omasal canal which communicates with the abomasum.
a slit-like opening in the avian urodeum.
aperture between the stomach and duodenum; opens infrequently, solely for the passage of ingesta.
paired orifices in the neck of the bladder.