PSIO 450 Study Guide - Respiratory Tract, Fibrocartilage, Acinus

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magentasalmon729

9 May 2014

School

University of Arizona

Department

Physiology

Course

PSIO 450

Professor

Fregosi

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Document Summary

Upper airway: where air enters the body: oropharynx, nasopharynx. Functions of mouth/nose to air: nose is better: moistens air, warms air. Innate immunity - traps pathogens: sensory -organ smells, filter barrier - epithelium, mucous layer - traps particles. Conducting zones: area of anatomic dead space: trachea, bronchi, bronchioles - terminal bronchioles, function of conducting zone - small surface area, no airway generation, conduction of air to alveoli. Important in innate immunity - mucociliary escalator: warming and moistening air, sensory in epithelium. Cell characteristics - trachea/bronchus: mucous - surfactant layer, epithelium - pseudostratified epithelium, basal cells -divide and differentiate, basement membrane. Lamina propria - attachment/ signaling: smooth muscle layer for contraction/ dilation, fibrocartilage layer - for firmness, systemic circulation here. Respiratory zone: alveolar/lung parenchyma: transitional bronchioles - both apart of the conducting zone and gas exchange, alveolar ducts, alveolar sacs, alveoli - the end of the lung is everywhere.

Related Questions

7. The pitot tube shown below is placed at a point where the velocity is 2.0 m/s. The specific gravity of the fluid is 2.0, and the upper portion of the manometer contains air. The reading h (m) on the manometer is most nearly:

A. 20.0

B. 10.0

C. 0.40

D. 0.20

8. Conditioned air enters a room at 13°C and 70% relative humidity. The dew-point temperature of the air is most nearly:

A. 5°C

B. 8°C

C. 10°C

D. 13°C

9. A heat exchanger is designed to heat liquid water from 150°C to 190°C inside tubes using steam condensing at 230°C on the outer surface of the tubes. For a constant flow rate, the effect of fouling of the heat transfer surfaces is to

A. increase the temperature rise of the water

B. decrease the temperature rise of the water

C. increase heat exchanger effectiveness

D. make no change in heat exchanger effectiveness

10. A helical compression spring has a spring constant of 38.525 N/mm and a free length of 190 mm. The force (N) required to compress the spring to a length of 125 mm is most nearly:

A. 1,500

B. 2,500

C. 4,800

D. 6,500

crimsonhornet860

3. 3 Stratosphere-troposphere exchange

The rate of exchange of air between the troposphere and thestratosphere is critical for determining the potential of variouspollutants emitted from the surface to reach the stratosphere andaffect the stratospheric ozone layer. One of the first estimates ofthis rate was made in the 1960s using measurements of strontium-90(90Sr) in the stratosphere. Strontium-90 is a radioactive isotope(half-life 28 years) produced in nuclear explosions. It has nonatural sources. Large amounts of 90Sr were injected into thestratosphere in the 1950s by above-ground nuclear tests. Thesetests were banned by international treaty in 1962. Following thetest ban the stratospheric concentrations of 90Sr began to decreaseas 90Sr was transferred to the troposphere. In the troposphere,90Sr is removed by wet deposition with a lifetime of 10 days (bycontrast there is no rain, and hence no wet deposition, in thestratosphere). An intensive stratospheric measurement network wasoperated in the 1960s to monitor the decay of 90Sr in thestratosphere. We interpret these observations here using a 2-boxmodel for stratosphere-troposphere exchange with transfer rateconstants kTS and kST (yr-1) between the tropospheric andstratospheric reservoirs. The reservoirs are assumed to beindividually well-mixed.

Let mS and mT represent the masses of 90Sr in the stratosphere andin the troposphere respectively. Observations of the decrease inthe stratospheric inventory for the period 1963-1967 can be fittedto an exponential mS(t) = mS(0)exp(-kt) where k = 0.77 yr-1.

1. Write mass balance equations for mS and mT in the 1963-1967period.

2. Assuming that transfer of 90Sr from the troposphere to thestratosphere is negligible (we will verify this assumption later),show that the residence time of air in the stratosphere is tS =1/kST = 1.3 years.

3. Let m'T and m'S represent the total masses of air in thetroposphere and the stratosphere, respectively. Show that theresidence time of air in the troposphere is tT = tS (m'T/m'S) = 7.4years. Conclude as to the validity of your assumption in question2.

4. Hydrochlorofluorocarbons (HCFCs) have been adopted asreplacement products for the chlorofluorocarbons (CFCs), which werebanned by the Montreal protocol because of their harmful effect onthe ozone layer. In contrast to the CFCs, the HCFCs can be oxidizedin the troposphere, and the oxidation products washed out byprecipitation, so that most of the HCFCs do not penetrate into thestratosphere to destroy ozone. Two common HCFCs have trade namesHCFC-123 and HCFC-124; their lifetimes against oxidation in thetroposphere are 1.4 years and 5.9 years, respectively. There are noother sinks for these species in the troposphere. Using our 2-boxmodel, determine what fractions of the emitted HCFC-123 andHCFC-124 penetrate the stratosphere.

PSIO 450 Study Guide - Respiratory Tract, Fibrocartilage, Acinus

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