ABSTRACT
Gross anatomy of the nose The external nose consists of a fixed bony case consisting of paired nasal bones dorsally and incisive and maxillary bones laterally (Figs 8.1A, B), and a cartilaginous framework, which is movable by virtue of several skeletal muscles including the levator nasolabialis and levator labii superioris muscles1,2. The nasal cartilages include the unpaired septal cartilage with the ventrally located paired vomeronasal cartilages enclosing the vomeronasal organ, the paired dorsal lateral and ventral
The respiratory system encompasses the nose and nasal cavities, pharynx, larynx, trachea, bronchi and smaller passageways, and functions to deliver air to the pulmonary alveoli where gas exchange occurs1. The nasal cavity and the conchae (also called turbinates) warm and moisten the air, remove foreign material and allow for olfaction. The nose consists of an external part with its associated nasal cartilages and ligaments and an internal part or nasal cavity with scrolls or conchae1. The gross and microscopic anatomy of the nose will be discussed first in this chapter, followed by a detailed description of its important functions, regulation and conditioning of the airflow and olfaction. The mechanisms involved in keeping the nose healthy and clean, mucosal cleaning,
A B
The nasal cavities extend from the nostrils with the nasal vestibule to the nasopharyngeal meatus and choanae, and are separated by the nasal septum, which consists of a bony, a membranous and a cartilaginous portion (Fig. 8.3). Each nasal cavity is divided into four principal air channels or nasal meatuses by three groups of cartilaginous or ossified nasal scrolls1. They include the dorsal, ventral and ethmoidal conchae, which were formerly called the dorsal nasoturbinates, the maxillo turbinates and the ethmoturbinates, respectively (Fig. 8.4). The latter are further subdivided into six small dorsally located ectoturbinates, some of which extend into the frontal sinuses,
lateral nasal cartilages and the paired lateral accessory cartilages (Fig. 8.2A). The paired vomeronasal organs (Jacobson’s organ) are tubular pockets of olfactory epithelium that open into an incisive duct that connects the nasal with the oral cavities3. The most apical portion of the nose, the nasal plane, is flattened and devoid of hair and glands (Fig. 8.2B). It includes the nares, which are separated from each other by a groove, or philtrum. Three ligaments, the unpaired dorsal nasal ligament and the paired lateral nasal ligaments, attach the mobile part of the nose to the dorsal portion of the osseous nose (Fig. 8.2A).
