Nasal cavity anterior region

Nasal cavity. The nasal cavity has a volume of 15 to 20 cm3 and a surface area of 150 to 180 cm2.110 111 The human nasal cavity is divided into two halves by the midline septum.45 107 Each cavity consists of three regions (1) vestibules, which are the anterior sections of the nasal cavity, (2) respiratory region, consisting of turbinates or chonchae (superior, middle, and inferior), and (3) olfactory region, which constitutes about 10 percent of nasal area.45 107... 

Particles deposited on non-ciliated regions (for example, the anterior of the nasal cavity) will move more slowly (such particles will land on mucus which is being dragged through the cavity from ciliated areas). 

As discussed above, nasal sprays tend to deposit at their impaction site, in the anterior, unciliated regions of the nasal cavity, where airflow associated with inspiration is high and mucociliary clearance is slow or erratic. Thus a drag moiety depositing in this region is cleared slowly and is transported over a large area en route to the pharynx. These factors promote drag absorption. 

The human nasal cavity, bearing a total surface area of about ISOcm and a total volume of about 15mL, is divided by a midline septum into two non-connected parts. As a cross-sectional view is schematically shown in Fig. lA, the nasal cavity consists of several major differentiated regions. " The nasal vestibule is situated just inside of the nostrils, with an area of about 0.6 cm. The epithelial cells in this region are stratified, squamous, and keratinized. The atrium located at the back of the vestibule is the narrowest region, and has stratified squamous cells anteriorly and pseudostrati-fied cells with microvilli posteriorly. The olfactory... 

The respiratory tract is divided into regions the nasopharyngeal airway (upper respiratory tract) and the tracheobronchial and pulmonary airways (lower respiratory tract). The anterior one-third of the nasal cavity viewed in cross-section reveals a central septum dividing the two cavities. This region, including the proximal portion of the inferior and middle turbinates, is non-ciliated (Figure 13.1). The meatuses are spaces formed by the folds of the two inferior and middle turbinates. In the posterior two-thirds of the nasal cavity, clearance of deposited par-... 

The brain resides within the cranial cavity. The bony roof and sides of the cranial vault make up the calvaria, which is composed of frontal, temporal and parietal bones and a small portion of the occipital bone. The floor of the cranial vault is divided into three depressions or fossae the anterior fossa extends from the region superior to the orbits and nasal cavity caudaUy as far as the posterior margin of the lesser wing of the sphenoid the middle fossa occupies the region between the lesser wing of the sphenoid and the anterior border of the petrous portion of the temporal bone and the posterior fossa, is underlain by the remainder of the temporal bones and the occipital bone. 

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