How many pairs of paranasal sinuses are there? Where is the opening?

Humans have four pairs of paranasal sinuses. They are:

1, maxillary sinus: located in the maxilla, opening in the middle and upper nasal meatus.

2. ethmoidal sinus: located in ethmoidal bone, opening in the middle and upper nasal meatus.

3. Cryptic sinus: located in sphenoid bone, opening at middle and upper nasal meatus.

4, sphenoid sinus: located in the sphenoid bone, opening in the upper nasal meatus.

Popular science of sinus and its function

Accessory sinuses are cavities in the skull that communicate with the nasal cavity. Humans have four pairs of paranasal sinuses, namely maxillary sinus, ethmoid sinus, saphenous sinus and sphenoid sinus. They all communicate with the nasal cavity, so that the gas and secretions in the nasal cavity can circulate freely between the paranasal sinuses and the nasal cavity.

The main functions of paranasal sinuses are to reduce the weight of the skull, increase the acoustic cavity, protect the brain and eyes, protect the respiratory tract and keep the nasal cavity moist. When the secretions in the nasal cavity cannot be discharged in time, it will lead to diseases such as sinusitis and affect human health.

1, reduce the weight of the head: the existence of sinuses reduces the weight of the head by about 50 grams, reducing the burden on the cervical spine.

2. Enlarge the * * * acoustic cavity: The existence of sinuses enlarges the * * * acoustic cavity and makes the sound louder.

3. Protect the brain and eyes: The existence of sinuses forms a buffer zone of the skull, which can effectively protect the brain and eyes.

4, protect the respiratory tract: the mucus in the paranasal sinuses can prevent harmful substances and bacteria in the air from entering the respiratory tract and play a role in protecting the respiratory tract.

5, keep the nasal cavity moist: the liquid secreted by the paranasal sinuses can keep the nasal cavity moist and avoid discomfort and infection caused by dry nasal mucosa.