Lying behind your eyebrows, behind your cheekbones, and between your eyes are your sinuses — air-filled cavities lined with a mucous membrane that filters and humidifies the air you inhale. This ...

The coronary sinus is a collection of smaller veins that merge together to form the sinus (or large vessel), which is located along the heart’s posterior (rear) surface between the left ventricle and ...

- any of the paired sinuses in the bones of the face adjacent to the nasal cavity that are lined with mucous membrane that is continuous with the lining of the nasal cavities ...