The |sphenoid bone| is one of the cranial bones and spans the inside of the |skull| laterally. The |sphenoid bone| has four wings: two greater and two lesser. The greater wings form part of the sides of the |skull|, with one greater wing on each side and extending inward to form also part of the back surface of each orbital cavity. The two lesser wings form a small part of the back surfaces of the orbital cavities, and meet in the middle of the |skull|. The |sphenoid bone| features two paranasal cavities, or ~sinuses~, called the sphenoids.
