What is the Eastern Time Zone? The Eastern Timezone is an area 5 hours behind Greenwich Mean Time ( GMT-5 ) during the winter months (referred to as EST) and 4 hours behind Greenwich Mean Time ( GMT-4 ) during the summer months (referred to as EDT). From 2 A.M. on the second Sunday in March to 2 A.M. on the first Sunday in November, Daylight Saving Time is in effect.
WHAT ARE SINUSES? Sinuses are air pockets that are located within the bones of the skull and face and are connected to your nasal passages by small tubes or channels, the osteomeatal complex. These channels permit air to flow from the nose into the sinuses and allow drainage of mucous from each sinus into the nose.
frontal sinus, one of a pair of small cavities in the frontal bone of the skull that communicate with the nasal cavity and lie above the orbits. The frontal sinuses are situated behind the superciliary arches and are lined with a mucous membrane that is continuous with that of the nasal cavity.rontal sinus one of the paired paranasal sinuses in the frontal bone, each communicating with the middle nasal meatus on the same side. intercavernous s's channels connecting the two cavernous sinuses, one passing anterior and the other posterior to the stalk of the pituitary gland.