Final answer:
The paranasal sinuses are air-filled spaces within the skull bones that help to warm and humidify air, produce mucus, add resonance to the voice, and lighten the skull's weight. They can cause changes in voice and discomfort when congested due to colds or sinus infections.
Step-by-step explanation:
The paranasal sinuses are air-filled spaces within the skull that have several functions. They are named for the skull bones they are associated with: the frontal sinus, maxillary sinus, sphenoidal sinus, and ethmoidal sinus. These cavities help to warm and humidify incoming air, produce mucus, reduce the weight of the skull, and add resonance to the voice. However, when you have a cold or other causes of sinus congestion, swelling of the sinus mucosa and excess mucus can block the passageways connecting the sinuses to the nasal cavity, leading to a change in your voice and sometimes discomfort or pain due to fluid buildup and pressure.
The maxillary sinuses are the largest and are commonly affected during sinus infections. Their drainage is challenging due to the location of their connection to the nasal cavity. The ethmoid air cells are small, multiple spaces in the ethmoid bone, which are situated between the upper nasal cavity and the medial wall of the orbit. The sphenoid sinus is a single midline sinus located within the sphenoid bone's body and is the most posterior sinus.