Final answer:
The paranasal sinuses are hollow, air-filled cavities in the skull. They include the frontal, maxillary, sphenoidal, and ethmoidal sinuses, each named after their respective skull bones and serve to lighten the skull, assist in warming and humidifying air, produce mucus, and enhance voice resonance.
Step-by-step explanation:
The paranasal sinuses are air-filled cavities within the skull that have various functions including lightening the weight of the skull, warming and humidifying incoming air, producing mucus, and adding resonance to the voice. The components of the paranasal sinuses, each named for the bone in which it is located, include:
- Frontal sinus - located above the eyebrows in the frontal bone.
- Maxillary sinus - the largest sinus, located within the right and left maxillary bones below the orbits.
- Sphenoidal sinus - located within the body of the sphenoid bone, just anterior and inferior to the sella turcica.
- Ethmoidal sinus (ethmoid air cells) - comprised of multiple small spaces within the ethmoid bone, situated between the orbital wall and upper nasal cavity.
These structures are lined with mucosa and play a role in ensuring the proper function of the nasal cavity and upper respiratory system.