Overview of Respiratory System

The respiratory system includes both upper and lower respiratory organs.

The upper respiratory organs consist of the nose and nasal cavity, paranasal sinuses, and pharynx.

The nose and nasal cavity act as the primary external openings for the body's airway, while the paranasal sinuses, air-filled cavities surrounding the nose, may help to moisten inhaled air.

The pharynx, or throat, connects the nasal cavity to the larynx and aids in exposing the immune system to inhaled antigens.

The lower respiratory system consists of the larynx, trachea, bronchial tree, alveoli, lungs, and pleurae.

The larynx, which connects the pharynx to the trachea, houses the glottis, epiglottis, and vocal cords.

The trachea, or windpipe, filters and carries air to the lungs. It branches into the right and left bronchi, forming the bronchial tree.

The lungs facilitate breathing and contain the alveoli, where gases are exchanged with the bloodstream.

The pleurae are the serous membranes that compartmentalize the lungs and produce lubricating fluid for the lungs and thoracic cavity.