The sigmoid sinus is a dural venous sinus that lies deep within the human head, and just below the brain. A dural sinus is a channel that lies between the dura mater, the outermost tissue covering the ...

The ethmoid sinus (one of six sets of sinuses) is part of the paranasal sinus system and is located between the nose and eyes. It is very small at birth and becomes walnut-sized during puberty. The ...