An air-filled cavity in a dense portion of a skull bone. The sinuses decrease the weight of the skull. The sinuses are formed in four right-left pairs. The frontal sinuses are positioned behind the forehead, while the maxillary sinuses are behind the cheeks. The sphenoid and ethmoid sinuses are deeper in the skull behind the eyes and maxillary sinuses. The sinuses are lined by mucous-secreting cells. Air enters the sinuses through small opening in bone called ostia. If an ostium is blocked, air cannot pass into the sinus and likewise mucous cannot drain out. Online Journals are scholarly and peer reviewed journals. The journals provide forum and motivates scientists, researchers, academics, engineers, and practitioners in all aspects to share their professional and academic knowledge in the fields computing, engineering, humanities, economics, social sciences, management, medical science, and related disciplines. Online Journals also aims to reach a large number of readers worldwide with original and current research work completed on the vital issues of the above important disciplines. The journals permit all readers to read, view, download and print the full-text of all published articles without any subscription or restrictions.
Last date updated on September, 2024
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