Respiratory system continued

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

The cells of the body require a continuous supply of oxygen to produce energy and carry out their metabolic functions. Furthermore, these aerobic metabolic processes produce carbon dioxide, which must be continuously eliminated. The primary functions of the respiratory system include ... 

The effect of rifaximin on cardiovascular (CY) and respiratory systems was investigated in anesthetized rats and guinea pigs, respectively [59]. Rifaximin was given intraduodenally at doses up to 100 mg/kg and carotid pressure and flow as well as heart rate were continuously measured in rats while respiration amplitude and frequency were monitored in guinea pigs. The rifamycin derivative did not affect any of the measured parameters at any time after its administration. 

A follow-up study of 29 workers with TMAN-induced immunologic lung disease who had been moved to low-exposure jobs for more than 1 year revealed that workers with late asthma or late respiratory systemic syndrome had improved symptoms, improved pulmonary functions, and lower total antibody against TMAN-HSA. In contrast, 7 of 12 workers with asthma rhinitis continued to have moderate to severe symptoms, abnormal pulmonary functions, and elevated IgE against TMAN-HSA. Elevated IgE against TMAN-HSA appears to be a marker for the subpopulation of workers with asthma rhinitis that does not improve. 

The rationale for basing air quality standards on smaller particles is evident from an examination of Fig. 2.12, a diagram of the human respiratory tract. Larger particles that are inhaled are removed in the head or upper respiratory tract. The respiratory system from the nose through the tracheobronchial region is covered with a layer of mucus that is continuously moved upward by the motion of small hairlike projections called cilia. Large particles deposit on the mucus, are moved up, and are ultimately swallowed. 

Inflammatory changes consisting of hyperemia and bronchitis were observed in the respiratory system of rabbits exposed to 4-6 mg/m (0.30-0.45 ppm) tributyltin chloride for 95 days (Gohlke et al. 1969). Histopathology, consisting of severe bronchitis and vascular and alveolar edema, was seen in rats exposed to 2 mg tin/m (0.41 ppm) as a mixture of tributyltin dibromide (0.39 ppm), dibutyltin bromide (0.02 ppm) and hydrocarbon impurities for 80 days (Iwamoto 1960). Since these were terminal histopathological evaluations only, it is not known whether the changes were reversible or would have produced functional impairment in the animals if exposure had continued. 

Vapor irritates the respiratory system. Vapor, solid, and solution irritate the eyes and burn the eyes and skin. Swallowing causes severe internal irritation and damage. Prolonged exposure to vapor causes disturbances of vision, while continued skin contact results in dermatitis and ulceration. Prevent inhalation of vapor. Prevent contact with eyes and skin.3 TLV-TWA 0.0002 ppm (0.0016 mg/m3) TLV-STEL 0.0006 ppm (0.0047 mg/m3).4... 

The ultimate example studied in this chapter is the mitochondrial respiratory system and oxidative ATP synthesis. This system, in which biochemical network function is tightly coupled with membrane transport, is essential to the function of nearly all eukaryotic cell types. As an example of a critically important system and an analysis that makes use of a wide range of concepts from electrophysiology to detailed network thermodynamics, this model represents a milestone in our study of living biochemical systems. To continue to build our ability to realistically simulate living systems, the following chapter covers the treatment of spatially distributed systems, such as advective transport of substances in the microcirculation and exchange of substances between the blood and tissue. 

High blood levels after topical application or injection of anesthetics may potentially cause systemic reactions. Toxic effects may appear in the central nervous system (CNS), cardiovascular system, or respiratory system. CNS toxicity appears initially as stimulation and may manifest itself clinically as nervousness, tremors, or convulsions. CNS depression, observed clinically as loss of consciousness and depression of respiration, usually follows. The earliest signs of cardiovascular involvement are hypertension, tachycardia, and, occasionally, cardiac arrhythmias. Late cardiovascular signs are hypotension, absent pulse, and weak or absent heartbeat. The effects on the cardiovascular system can develop either simultaneously with CNS depression or alone. If allowed to continue, such cardiac depression and resultant peripheral vasodilation are followed by secondary respiratory failure. 

Congested lungs were observed in rats exposed to 1 mg/m3 metallic mercury vapors for 100 hours continuously per week for 6 weeks (Gage 1961). In rats exposed to 3 mg/m3 mercury vapor for only 3 hours a day, 5 days a week for 12-42 weeks, pathological examination revealed no significant changes in the respiratory system (Kishi et al. 1978). The potential for oral exposure was not quantified in these studies however, it is likely that most of the exposure was via inhalation. 

The concept of the photosynthetic and respiratory systems is that they are based on the rapid flow of electrons through a graded sequence of redox steps mediated by a continuous sequence of carriers [Change (27)]. Hemoproteins play an important role here, as do other "organic carriers like quinones, flavins, and copper and iron proteins. 

The majority of toxic substances in the air are present in the gaseous state, a smaller portion being in the form of aerosols and dust. The substances from the air enter the organism via the respiratory tract (inhalation). In contrast to toxic substances occurring in water, pollutants in the atmosphere exert continuous and long-term effects. They represent a health hazard and catastrophic events can sometimes occur. They affect the cardiovascular and respiratory systems (Table 9.9). They also exert negative effects on the nervous system, increasing its instability. 

In coastal areas that receive seawater containing large amounts of sulfate, the reduction of sulfate to sulfide provides a few species of true anaerobes with a respiratory system that can support considerable oxidative activity. In noncultivated coastal marshes where most of the active iron is in the reduced form, it has been estimated that much of the respiratory activity is due to sulfate. In these areas the soil often stays wet most of the year preventing the iron from oxidizing to the ferric form, while sulfate is continuously supplied from the sea. In inland areas where rice culture is more important the limited amount of sulfate in the soil does not support significant anaerobic respiration. 

Chapter 11 presents models used to study the continual interaction of the respiratory mechanical system and pulmonary gas exchange. Traditionally, the respiratory system is described as a chemo-stat — ventilation increases with increased chemical stimulation. Alternatively, the author proposes that quantitative description of the respiratory central pattern generator, a network of neuronal clusters in the brain, is a much more sophisticated and realistic approach. Study of this dynamic, optimized controller of a nonlinear plant is interesting from both physiological and engineering perspectives, the latter due to applications of these techniques for new, intelligent control system design. 

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