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Toxic Responses of the Lung
Published in Stephen K. Hall, Joana Chakraborty, Randall J. Ruch, Chemical Exposure and Toxic Responses, 2020
The nose consists of an external and internal portion. The upper part of the external portion is held in a fixed position by the supporting nasal bones that form the bridge of the nose. The lower portion is movable because of its pliable framework of fibrous tissue, cartilage, and skin. The internal portion of the nose lies within the skull between the base of the cranium and the roof of the mouth, and is in front of the nasopharynx. The nasal septum is a narrow partition that divides the nose into right and left nasal cavities. The nasal cavities open into the nasopharynx. The vestibule of each cavity is the dilated portion just inside the nostril. Toward the front, the lining of the vestibule is lined with skin and represents a ring of coarse hairs which serve to trap dust particles. Toward the rear, the lining of the vestibule changes from skin to a highly vascular ciliated mucous membrane, called the nasal mucosa, which lines the rest of the nasal cavity.
Toxic and Asphyxiating Hazards in Confined Spaces
Published in Neil McManus, Safety and Health in Confined Spaces, 2018
The nose is an effective temperature conditioning and humidifying structure. The effectiveness of the nose in performing these functions is related to its internal structure. Interior folds in the nasal passages produce a large surface area (about 160 cm) within a relatively small volume (20 mL). A sticky, moist and warm mucosal layer covers these surfaces (Bouhuys 1974).
Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
Multifunctionality is a versatile feature in nature. The human tongue is a taste sensor and also used in speech. The human nose is used for smelling and breathing. Similarly, many other organs serve multiple functions. Multifunctionality is also expected from nanosensors.
Simulated airflow and rigid fiber behavior in a realistic nasal airway model
Published in Particulate Science and Technology, 2018
Kevin T. Shanley, Goodarz Ahmadi, Philip K. Hopke, Yung-Sung Cheng
Among other functions, the human nose serves to remove particles from inhaled air. This function protects the lungs and more sensitive regions of the respiratory tract from damage due to particle deposition. The original investigation into the human nasal airway deposition was performed by Swift and Proctor (1977) with in vitro experiments on a cast reconstructed from a mold taken from a cadaver. A miniature pitot tube was used in different locations within their life-sized nasal passage replica to obtain velocity measurements. Considerable understanding of the flow field inside the human nose was gained from this study. Guilmette, Wicks, and Wolff (1989) determined, however, that this model generation method provides a less than accurate representation of the cavity of a living human as the airways are prone to collapse shortly after death.
Airflow patterns and particle deposition in a pediatric nasal upper airway following a rapid maxillary expansion: Computational fluid dynamics study
Published in Cogent Engineering, 2023
John Valerian Corda, Jeny Emmanuel, Supriya Nambiar, Prakashini K, Mohammad Zuber
The human nasal cavity is responsible for critical physiological functions. Apart from respiration which supports the very existence of life on earth, the nose carries out other functions such as the filtering of unwanted dust particles from reaching the lungs, thermal control, and humidification of the inspired air to the required conditions in addition to providing a sense of smell (Elad et al., 1993). Airway patency and dental malocclusions have always been studied under a plethora of scientific evidence. A constricted upper airway is significantly associated with a certain type of dental malocclusions and such patients fall under the high-risk category of developing obstructive breathing with a partially/completely collapsed upper airway, more commonly known as sleep-disordered breathing or obstructive sleep apnoea. One of the distinguishing features of a Class III malocclusion is maxillary hypoplasia with palatal constriction. Many authors have reported improvement in the upper airway characteristics following maxillary protraction via Dentofacial Orthopaedic growth modulation therapy. Protraction of the maxilla with simultaneous expansion using a face mask with Alt-RAMEC protocol has proven to be a successful treatment modality in Class III malocclusion with maxillary hypoplasia, in children within the age group of 9–12 years. There was a recorded increase in the length of the maxilla and mandible and the vertical height of the face. In addition to this, the maxillary forward position and the nasopharyngeal area saw a significant increase as a result of the treatment (Tuncer et al., 2009). A study conducted to evaluate the maxillary sinuses in growing subjects showed that sinuses develop early in females. The sinus grows particularly in the age groups of 9–14 years for males, whereas for females, it is from 6 to 11 years. Vertical development of the sinus was observed during the growth that resulted in an increased volume (Maspero et al., 2020). Researchers have also indicated that the increase in airway dimensions due to maxillary protraction may be minor in magnitude (Havakeshian et al., 2020). Yilmaz and Kucukkeles (2014) evaluated airway measurements using CBCT after 9 weeks of Alt-RAMEC protocol in an airway study. They reported an enhancement in the upper airway and nasal width. Celikoglu and Buyukcavus (2017) examined how different Alt-RAMEC protocols affected the airway after maxillary protraction and found that the effects of each protocol were similar. In 2018, a study (Büyükçavuş, 2019) used CBCT to investigate how the Alt-RAMEC protocol affected the airway. In this study, the RME protocol and the Alt-RAMEC protocol were compared in patients. They concluded that both groups’ increases in nasal and nasopharyngeal volume were comparable. Kaygisiz et al. (2009) observed an improved airway due to face mask treatment which was retained up to 4 years post-treatment.