Iron retention was studied in rats (Rattus norvegicus), doves (Streptopelia d. decaocto) and two species of mynahs (Acridotheres t. tristis and Gracula r. religiosa) fed two different pelleted diets (88.5 and 567.9mg Fe/kg diet). The doves and rats served as species that are not susceptible to iron storage, whereas the mynahs are known to develop iron overload frequently. The retention was calculated after measuring the uptake and elimination of a single dose of radioactive iron (⁵⁹Fe) using whole-body counting. It was hypothesized that the mynahs would retain more iron than the rats and doves, and that after dietary iron challenge the mynahs would downregulate iron retention less effectively. It is concluded that mynahs have much higher iron uptake and retention than doves, but a similar uptake to that in rats. The four studied species are able to downregulate iron retention, the doves being the most efficient. It is suggested that at least part of the susceptibility to iron overload in mynahs is related to a high iron absorption from the intestines regardless of body iron stores, which is comparable with the situation of hereditary haemochromatosis in man.

In this chapter, we scope the importance of functional anatomy and physiology of the upper airway. The upper airway has an important role in transporting air to the lungs. Both the anatomical structure of the airways and the functional properties of the mucosa, cartilages, and neural and lymphatic tissues influence the characteristics of the air that is inhaled. The airway changes in size, shape, and position throughout its development from the neonate to the adults. Knowledge of the functional anatomy of the airway in these forms the basis of understanding the pathological conditions that may occur. The upper airway extends from the mouth to the trachea. It includes the mouth, the nose, the palate, the uvula, the pharynx, and the larynx. This section also describes the functional physiology of this airway. Managing the airway of a patient with craniofacial disorders poses many challenges to the anesthesiologist. Anatomical abnormalities may affect only intubation, only airway management, or both. This section also focuses on the abnormal airways in obesity, pregnancy, children and neonate, and patients with abnormal facial defects.

Because intubation becomes a long procedure as potential, arterial oxygen (O2) desatu-ration should be taken into account during the intubation. Since oxygen reserves are not always sufficient to meet the duration of intubation, preoxygenation should be routine before anesthetic induction and tracheal intubation. Surveys show that maximal preoxygenation increases oxygen reserves in the body and significantly delays arterial hemoglobin desaturation and hypoxia. In cases of respiratory insufficiency oxygenation can be improved by positive end expiratory pressure (PEEP) or pressure support. Effective technique and FeO2 monitoring can increase the effectiveness of preoxygenation and thus increase the safety margin. Preoxygenation failures have to be identified and alternative oxygenation methods must be readily available in order to be applied quickly and easily. Although genetic and environmental factors play a role in diseases such as heart attack, stroke and cancer, which have become the cause of the worst death in the twenty-first century, the underlying problem in the development of these pathological conditions is hypoxia. Better understanding of hypoxic areas in ischemic tissues or growing tumors as well as increased knowledge of hypoxia cellular and molecular responses will allow possible applications in the treatment of major diseases associated with tissue hypoxia.