=====Lamina papyracea===== {{http://www.3dneuroanatomy.com/wp-content/uploads/2014/12/orb5.jpg}} http://www.3dneuroanatomy.com/wp-content/uploads/2014/12/orb5.jpg (or orbital lamina) is a smooth, oblong bone plate which forms the lateral surface of the labyrinth of the [[ethmoid bone]] in the [[skull]]. The plate covers in the middle and posterior ethmoidal cells and forms a large part of the medial wall of the [[orbit]]. It articulates above with the orbital plate of the [[frontal bone]], below with the [[maxilla]] and the orbital process of [[palatine bone]], in front with the [[lacrimal bone]], and behind with the [[sphenoid]]. Its name lamina papyracea is a literal description, as this part of the ethmoid bone is paper-thin and fractures easily. A fracture here could cause entrapment of the [[medial rectus muscle]].