1. Plural of ostium; small openings or mouths, especially in anatomy or zoology.
Usage: technical; anatomy; biology
2. The plural form of ostium, referring to the openings through which blood enters the heart chambers in certain organisms.
Usage: zoology; comparative anatomy

Examples

• The ostia of the heart allow blood to flow into the atria.
• In arthropods, ostia serve as entry points for hemolymph into the heart.
• The microscope revealed multiple ostia along the vessel wall.
• Ostia are critical structures in the circulatory systems of invertebrates.