The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are lungs, which carry out this exchange of gases as we breathe. Parts of respiratory system are nose, paranasal air sinuses, nasopharynx, larynx, trachea, bronchi and lungs. This chapter covers the nasal cavity, pleura, and names of paranasal air sinuses. The nasal cavity is pyramidal in shape and is divided into two halves by a septum. The two halves open on the face through anterior nasal apertures and posteriorly into nasopharynx, through posterior nasal apertures. Paranasal air sinuses are air-filled spaces lined by mucous membrane present around and communicate with the nasal cavity. These are pairs of maxillary, ethmoidal, frontal, sphenoidal sinuses. Diaphragm is a dome-shaped musculoaponeurotic partition which intervenes between the thorax and the abdomen. The thoracic surface is convex on the right and left sides, and is depressed in the middle; the summits of the convexities are known as cupolae. In this chapter, long essay type and short essay type questions are also provided.