opening in the side wall of the heart that receives blood from the pericardial cavity
one of three pairs of tiny, valved openings that allow blood to enter the heart from the pericardial cavity
pores in the walls of sponges through which water passes.
Latin = a door, an opening, an orifice.
opening to the proximal end of the oviduct
Any of numerous openings present in sponges through which water is drawn in.
"Door" in Latin. The opening in the cervix that connects the uterine cavity with the vagina. Also, the “tubal ostia” refer to the openings of the fallopian tubes into the uterine cavity.
ostium = door or opening.
The opening point at which each sinus empties into the nasal cavity. The frontal, maxillary and sphenoid sinuses each have a small sinus ostium. In contrast, the ethmoid sinuses have multiple small sinus ostia.
A small opening connecting the sinuses to the nose.
Small opening into a tubular duct or organ