Final answer:
The nasal cavity is divided into two chambers by the nasal septum, which is the correct answer to the provided question (Option D). The nasal septum, consisting of both cartilage and bone, serves to separate the left and right sides of the nasal cavity.
Step-by-step explanation:
The nasal cavity is a crucial part of the respiratory tract that is responsible for warming, humidifying, and filtering inhaled air. An important structural feature of the nasal cavity is the division into two chambers, which is crucial for its function. This division is achieved by a structure known as the nasal septum. The nasal septum is a partition formed anteriorly by the septal cartilage and posteriorly by bones such as the perpendicular plate of the ethmoid bone and the vomer bone. Its primary role is to separate the nasal cavity into left and right halves, ensuring a streamlined flow for the inhaled air.
When answering the question provided, which is to identify the structure that divides the nasal cavity into two chambers, the correct answer is D. nasal septum. Options such as the frontal sinus, middle turbinate, and zygoma do not serve the same function. The frontal sinus is one of the paranasal sinuses involved in lightening the weight of the skull and aiding in the humidification and warming of the air, whereas the middle turbinate is a part of the ethmoid bone that projects into the nasal cavity to increase surface area and enhance air filtration and humidification. The zygoma is a bone that forms the prominence of the cheek, not involved in dividing the nasal cavity.