Where Is the Respiratory Tract Located?
The respiratory tract is a large, contiguous system comprised of several structures. The respiratory system begins at the nostrils, involves several structures of the head, continues down the neck and ends at the lungs that lie in the chest cavity. The nose is positioned in the center of the face. The structure and length of the nose varies greatly in dogs. In dolichocephalic breeds of dogs (e.g. collie, Doberman pinscher, German shepherd dog), the nose is quite long and prominent. In brachycephalic breeds of dogs (e.g. pug, Pekingese, Lhasa apso, bulldog), the nose is quite short and flattened. The nasal passages lie within the nose between the nostrils and the back of throat. There are two passages, one on each side of the nose. They are separated by a bony plate or septum until they end at the nasopharynx.The nasal cavity is surrounded by sinuses. The sinuses are air filled spaces within the bones of the skull. The major sinuses lie just below and above both eyes.The pharynx is the
