Respiratory system, anatomy

Nitrogen oxides combustion appliances cooking ETS. irritation of respiratory system and eyes decreased in pulmonary function in asthmatics decreased immune capacily, changes in anatomy and function of lung. 

Netter FH, In Respiratory System A Compilation of Paintings Depicting Anatomy and Embryology, Physiology, Pathology, Pathophysiology, and Clinical Features and Treatment of Diseases (Eds Divertie MB, Brass A), pp. 46-59. CIBA Pharmaceutical Company, Summit, NJ, 1980. 

Fig. 3.1 Schematic diagram of the human respiratory system. The gross anatomy of the lung, the covering membranes (pleura), airways and air sacs (alveoli) are shown. The average diameter of portions of the air flow system are indicated trachea, 20 mm bronchus, 8 mm terminal and respiratory bronchioles, 0.5 mnn alveolar duct, 0.2 mm alveolar sacs, 0.3 mm.

Anatomy and physiology. The human respiratory system is divided into upper and lower respiratory tracts. The upper respiratory system consists of the nose, nasal cavities, nasopharynx, and oropharynx. The lower respiratory tract consists of the larynx, trachea, bronchi, and alveoli, which are composed of respiratory tissues. 

Figure 27.1. Anatomy of the human respiratory system. (Adapted from Life ART illustration series, Lippincott Williams Wilkins, Hagerstown, MD, 1994. This figure was completely redrawn by the author from materials cited.)...

The methods the USEPA uses in the derivation of inhalation RfDs are similar in concept to those used for oral RfDs however, the actual analysis of initiation exposures is more comple.x tlian oral e. posurcs due to (1) the dynamics of the respiratory system and its diversity across species, and (2) difTcrcnces in the physiochcmical (both physical and chemical) properties of contaminants. Although the identification of the critical study and the determination of the NOAEL in theory are similar for oral and inlralalion e.xposures, several important differences should be noted. In selecting the most appropriate study, the USEPA considers differences in respiratory anatomy and physiology, as well as differences in the physicochemical characteristics of tire contaminant. Differences in respiratory anatomy and physiology may affect the pattern of contaminant deposition in the respiratory tract, and the clearance and redistribution of the agent. Consequently, the different species may not receive the same dose of the contaminant at the same locations within the respiratory tract even though both species were exposed to the same particle or gas concentration. Differences in the physicochemical characteristics of the contaminants, such as the size and shape of a particle or whether the contaminant is an aerosol or a gas, also influence deposition, clearance, and redistribution. 

Gaseous pesticides are evenly dispersed in the air. In the case of inhalation, the anatomy and physiology of the respiratory system diminishes the pesticide concentration in inspired air. As pesticides are mostly lipid-soluble, they are usually not removed in the upper airways but tend to deposit in the distal portion of the lung, the alveoli [83] and may then be absorbed into the blood stream. 

Eyelashes are also important to adornment. Eyelashes protect the eyes from sunlight and foreign objects, and they assist in communication. Nasal hairs filter inspired air and retard the flow of air into the respiratory system, thus allowing air to be warmed or cooled as it enters the body. Hair on other parts of the anatomy serves related functions. In addition, a general function of all hairs is as sensory receptors because all hairs are supplied with sensory nerve endings. The sensory receptor function can enhance hair in its protective actions. 

Marked ethnic differences in infant mortahty and respiratory morbidity have been reported (130). Prematnrely dehvered Afro-Caribbean infants are less likely to develop the respiratory distress syndrome (RDS) than white infants of similar gestational age (131), which snggests that the respiratory system is either more matnre or that airway function is enhanced in black preterm infants (132). Some of these differences may be attributed to differences in nasal anatomy, since the lower total airway resistance found in Afro-Caribbean infants when compared with Caucasian infants of similar age and weight (101) was accounted for by their lower nasal resistance (23). Such differences would be expected to influence both breathing patterns and the distribution of inhaled aerosols. 

Pulmonology Study of the basic anatomy, physiology, and function of the respiratory system. 

Pulmonary medicine is a branch of medicine that is concerned with the maintenance and function of the respiratory system. It deals with causes, diagnoses, and treatments of diseases that affect the lungs and related systems, such as sleep, that are strongly supported by an efficiently working respiratory system. Pulmonary medicine is often confused with pulmonology, which is the scientific study of the basic anatomy, physiology, and function of the respiratory system. Practitioners of pulmonary medicine are called pulmonologists. 

Relative to body weight, humans have a much lower respiratory rate and cardiac output than rodents. These are the two primary determinants of systemic uptake of volatile chemicals. Therefore, at similar nominal concentrations, rodents absorb substantially more cyanide than primates. From a pharmacokinetic view, lower hepatic rhodanese levels in primates will not be significant at high, acute HCN exposures. It should be noted that Barcroft s subject withstood a 1 min and 31 s exposure at approximately 500 to 625 ppm without immediate effects (Barcroft 1931), whereas mice suffer asphyxia during a 2 min exposure at 500 ppm (Matijak-Schaper and Alarie 1982). Compared with rodents, the respiratory tracts of humans and monkeys are more similar in gross anatomy, the amount and distribution of types of respiratory epithelium, and airflow patterns (Barrow 1986 Jones et al. 1996). 

For more detailed information on the respiratory tract, the pleura, and the lymphatic system, consult Gray s Anatomy or other standard medical texts. A comprehensive review of the lung and its structure and function is presented in Nagaishi (1972). 

FIGURE 19-1 Biochemical anatomy of a mitochondrion. The convolutions (cristae) of the inner membrane provide a very large surface area. The inner membrane of a single liver mitochondrion may have more than 10,000 sets of electron-transfer systems (respiratory chains) and ATP synthase molecules, distributed over the membrane surface. Heart mitochondria, which have more profuse cristae and thus a much larger area of inner membrane, contain more than three times as many sets of electron-transfer systems as liver mitochondria. The mitochondrial pool of coenzymes and intermediates is functionally separate from the cytosolic pool. The mitochondria of invertebrates, plants, and microbial eukaryotes are similar to those shown here, but with much variation in size, shape, and degree of convolution of the inner membrane. 

FIGURE 2.37 Thoracic duct and other vessels of the thorax. Lymphatic capillaries are most numerous just beneath body surfaces, such as the skin and the mucus membranes of the gastrointestinal and respiratory tracts. The mucus membrane of the gastrointestinal tract is called the gut mucosa. The general function of these capillaries is to absorb interstitial fluid that has leaked from the circulatory system and to return it to the bloodstream. The function of the l)miphatic capillaries that end in the lacteals of the small intestine is to transport absorbed dietary lipids. These capillaries coalesce and eventually deliver their contents to the thoracic duct. The lymph collected from other parts of the body, as indicated by the "collecting trunk," also is transferred to the thoracic duct. [Redrawn with permission, from "Grant s Atlas of Anatomy," Williams Wilkins Co., Baltimore, 1978.]... 

FIGURE 11.2 Anatomy of the human respiratory tract. Deposition of nerve agent vapor or aerosols in the different regions of the lung can lead to different symptomology. Upper airway deposition can lead to immediate respiratory distress. Alveolar deposition leads to systemic distribution of the nerve agent. 

The ability to diagnose and treat dysfunctions related to cranial osteopathy and the primary respiratory mechanism (PRM) requires a solid knowledge of the anatomy of the cranium and the central nervous system, cerebral and spinal. 

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