Respiratory cycle phases

The respiratory rate is reduced such that each complete respiratory cycle takes longer. This is usually a result of a prolonged expiratory phase, so it is the plateau that you should demonstrate to be extended. The Petco2 will be raised as a consequence. 

During the respiratory cycle, the volumetric flow rate of air varies from zero up to a maximum and back. Usually, the expiratory phase is longer than the inspiratory phase, and there may be intervening pauses... 

In addition to the electrical brain and muscle activity used to differentiate between the sleep-wake cycle phases, other physiological parameters such as heart and respiratory rate, and body or brain temperature, can also be recorded. This may provide... 

Tc-MAA is injected intravenously with the patient in supine position. Prior to injection, the syringe should be inverted repeatedly to resuspend sedimented macroaggregates they should be injected slowly over a period of at least 30 s to normalize different phases of the respiratory cycle (Wagner 1995). 

The two-phase respiratory cycle maybe expanded into three phases if the expiratory phase is subdivided into an early postinspiratory inspiratory phase (stage I) and a late expiration phase (stage II). Vagal feedback has differential effects on neural activities during the two stages of expiration [St. John and Zhou, 1990]. 

A mode of ventilation is a way of communicating an important set of characteristics in only a few words. Once we understand the ventilator control characteristics and how a particular variable is used to switch from one phase of the respiratory cycle to another, modes of ventilation become very easy to understand. For example, when we describe pressure limited modes, we use the cycle criteria to describe... 

The lamellar body contents are secreted from the apices of the type 11 cells into the alveoli. Secretion appears to involve membrane fusion and exocytosis into the hypophase between the cell and the air surface. After their release, the lamellar bodies become hydrated in the aqueous subphase and unravel into a matrix of tubular myelin (Fig. 2). Tubular myelin is hypothesized to release phospholipid spontaneously to the air-liquid interface where the phospholipids reside in thermodynamically favorable orientation with the acyl chains extending into the air phase, whereas the head groups remain submerged in the aqueous phase. After one or several respiratory cycles, the surfactant material is then forced back into the aqueous phase, where the surfactant forms bilayer vesicles. The vesicles may then enter into either a recycling or degradative pathway (31). 

Many estimates of total terrestrial net primary production are available, ranging between 45.5 Pg C/yr (Lieth, 1972) and 78 Pg/yr (Bazilevich et al., 1970). Ajtay ef oZ. (1979) have revised the various estimates and methods involved, they also reassess the classifications of ecosystem types and the extent of the ecosystem surface area using new data and arriving at a total NPP of 60 Pg C/yr. Gross primary production is estimated to be twice net primary production, i.e., 120 Pg C/yr. This implies that about 60 Pg C/yr are returned to the atmosphere during the respiratory phase of photosynthesis. It is well known that carbon dioxide uptake by plants follows daily cycles most plants take up CO2... 

Under aerobic conditions, the glycolytic pathway becomes the initial phase of glucose catabolism (fig. 13.2). The other three components of respiratory metabolism are the tricarboxylic acid (TCA) cycle, which is responsible for further oxidation of pyruvate, the electron-transport chain, which is required for the reoxidation of coenzyme molecules at the expense of molecular oxygen, and the oxidative phosphorylation of ADP to ATP, which is driven by a proton gradient generated in the process of electron transport. Overall, this leads to the potential formation of approximately 30 molecules of ATP per molecule of glucose in the typical eukaryotic cell. 

The beat cycle of a respiratory tract cilium is composed of three phases ... 

In bacterial chromatophores the RC and the b/c, complex are arranged to form a cyclic electron transfer system possibly mediated by the diffusion of ubiquinone and cyt. Cj these carriers are, however, also coupled to other multienzyme complexes forming the respiratory chain and perform the aerobic metabolism of these facultative photosynthetic organisms [254]. The electrogenic steps of the photosynthetic cycle take place both within the RC and the 6/cj complexes and can be monitored by the electrochromic spectral shift of endogenous carotenoids and on the basis of their response to specific inhibitors and kinetics. When induced by a short laser flash the carotenoid signal displays three distinct kinetic phases (r,/2 10 h/i 5 jas... 

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