Search results
Results from the WOW.Com Content Network
The, paranasal sinuses are joined to the nasal cavity via small orifices called ostia. These become blocked easily by allergic inflammation, or by swelling in the nasal lining that occurs with a cold. If this happens, normal drainage of mucus within the sinuses is disrupted, and sinusitis may occur. Because the maxillary posterior teeth are ...
The ethmoid sinuses or ethmoid air cells of the ethmoid bone are one of the four paired paranasal sinuses. [1] Unlike the other three pairs of paranasal sinuses which consist of one or two large cavities, the ethmoidal sinuses entail a number of small air-filled cavities ("air cells"). [ 2 ]
Maxillary sinuses. Frontal sinuses, seen with an oblique view. Ethmoidal cells. Sphenoid sinus, seen through the open mouth. Odontoid process, where if it is just below the mentum, it confirms adequate extension of the head. The frontal sinus may not show the frontal sinus in detail. [1]
The nasal cavity and the paranasal sinuses are referred to as the sinonasal tract or sinonasal region, and its anatomy is recognised as being unique and complex. [30] [31] Four paired paranasal sinuses – the frontal sinus, the sphenoid sinus, the ethmoid sinus and the maxillary sinus drain into regions of the
A sinus is a sac or cavity in any organ or tissue, or an abnormal cavity or passage. In common usage, "sinus" usually refers to the paranasal sinuses, which are air cavities in the cranial bones, especially those near the nose and connecting to it. Most individuals have four paired cavities located in the cranial bone or skull.
Each cavity is the continuation of one of the two nostrils. The nasal cavity is the uppermost part of the respiratory system and provides the nasal passage for inhaled air from the nostrils to the nasopharynx and rest of the respiratory tract. The paranasal sinuses surround and drain into the nasal cavity.
The cavity also extends into neighbouring skull bones, forming additional air cavities known as paranasal sinuses. [9] In cetaceans, the nose has been reduced to one or two blowholes, which are the nostrils that have migrated to the top of the head. This adaptation gave cetaceans a more streamlined body shape and the ability to breathe while ...
Skeletal pneumaticity is the presence of air spaces within bones. It is generally produced during development by excavation of bone by pneumatic diverticula (air sacs) from an air-filled space, such as the lungs or nasal cavity.