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95 Cards in this Set
- Front
- Back
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Structures that make up the conducting zone of respiratory tree
What do its walls contain? where is there cartilage? |
nose, pharynx, trachea, bronchi, bronchioles, terminal bronchioles
walls contain smooth muscle cartilage in trachea, and bronchi |
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respiratory zone of the respiratory tree
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respiratory bronchioles, alveolar ducts, alveoli
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what makes up the anatomic dead space
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conducting zone of the respiratory tree
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what is the job of the conducting zone of the respiratory tree?
respiratory zone? |
condicting zone: brings air in and out; warms, humidifies, and filters air
respiratory zone: gas exchange |
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Pneumocytes
What type of cells? 2 types? where? |
pseudostratified ciliated columnar cells extend to respiratory bronchioles
Type I (alveolar surfaces) for gas diffusion; Type II (only 3%) secrete surfactant |
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What clears debris in lung alveoli?
How are mucus secretions cleared? |
macrophages clear debris in alveoli
swept out of lung to mouth by ciliated cells |
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Type I pneumocytes
a. where do you find them b. type of cells c. job |
a. cover 97% of alveolar surfaces
b. squamous cells c. thin for gas diffusion |
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Type II pneumocytes
a. type of cells b. where c. jobs |
a. cuboidal, clustered
b. cover 3% of alveolar surfaces c. produce surfactant, serve as precurosrs to type I and other type II cells, proliferate in lung damage |
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Clara cells
a. structure b. 3 jobs |
a. columnar w/secretory granules, nonciliated, lamellar bodies
b. secrete component of surfactant, degrade toxins, act as reserve cells |
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bronchopulmonary segments
What makes up each bronchopulmonary segment |
tertiary (segmental) bronchus + 2 arteries (bronchial and pulmonary) in the center
veins and lymphatics drain along the borders |
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How are pulmonary arterial pressures kept constant throughout the cardiac cycle
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elastic walls
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how many lobes
right lung? left lung? |
right = 3
left = 2 lobes + lingula |
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What is the relationship between the pulmonary artery to the bronchus at the right and left lung hilus
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RALS
right anterior, left superior |
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If you aspirate a peanut, where will it go if you are upright?
if you are supine? |
right bronchus (wider and more vertical) --> lower portion of right inferior lobe
superior portion of right inferior lobe |
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what rib line demarcates the border of the superior and middle lobe in the right lung?
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4th rib (horizontal fissure)
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In what dermatomal level would you find the oblique fissure from the posterior view of the lung
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T2
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3 structures that perforate the diapharagm
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T8: IVC
T10: esophagus, vagus T12: aorta (red), thoracic duct (white), azygous vein (blue) I (IVC) ate (8) 10 eggs (esophagus) at (aorta) 12 |
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Innervation of the diaphragm
pain in diaphragm refers to where |
C3-C5
referred pain to shoulder |
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What muscles do you use?
a. quiet inspiration b. quiet expiration c. exercise inspiration d. exercise expiration (4) |
a. diaphragm
b. passive c. external intercostals, Scalene, Sternomastoids d. rectus abdominis, internal and external obliques, transversus abdominis, internal intercostals |
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You detect a lecithin-to-sphingomyelin ratio of >2.0 in the amniotic fluid.
what does this tell you |
fetal lung maturity
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Surfactant
-3 jobs -produced by what type of cells |
-decreases alveolar surface tension
-increases compliance -decreases the work of inspiration produced by type II pneumocytes |
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surfactant is made up of what chemical?
In what condition do you see a deficiency |
dipalmitoyl phosphatidylcholine (lecithin)
neonatal RDS |
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5 important lung products
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1. surfactant
2. prostaglandins 3. histamine (bronchoconstricts) 4. ACE (AII; inactivates bradykinin) 5. kallikrein (activates bradykinin) |
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how do ACE inhibitors work in the lung
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prevent production of ACE, so increases bradykinin --> cough and angioedema
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how do you calculate collapsing pressure on the alvolus?
what happens to collapsing pressure as radius of the alveolus decreases? |
collapsing pressure = (2 * surface tension) / radius
tendency to collapse on expiration as the radius decreases (law of Laplace) |
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Lung volumes
what is the residual volume (RV)? can it be measured with spirometry? |
Air in lung after maximal expiration
cannot be measured on spirometry |
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Lung volumes
Expiratory reserve volume (ERV) |
air that can be still breathed out after normal expiration
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Lung volumes
Tidal volume |
air that moves into the lung with each quiet inspiration typically 500mL
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Lung volumes
Inspiratory reserve volume (IRV) |
air in excess of the tidal volume that moves into the lung on maximum inspiration
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Lung volumes
Vital capacity |
TV + IRV + ERV
everything except the residual volume |
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Lung volumes
Functional residual capacity |
RV + ERV = volume in lungs after normal expiration
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Lung volumes
Inspiratory capacity |
IRV + TV
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Lung volumes
Total lung capacity |
lc = IRV + TV + ERV + RV
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Lung volumes
what is a capacity? |
capacity is a sum of 2 or more volumes
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What is physiologic dead space?
What are 2 components? Where do you find the largest component? how do you calculate it? |
volume of inspired air that does not take place in gas exchange
conducting airways (anatomic) + alveoli (functional) largest contributer is apex of lung VD = tidal vol. * [(PaCO2 - PeCO2)/PaCO2)] |
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What is the system pressure at functional residual capacity and how does this affect the balance of lung and chest wall forces?
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system pressure is atmospheric
tendency for inward pull of lungs is balanced by the outward pull of the chest wall |
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FRC
a. what is the airway/alveolar pressure b. what is the intrapleural pressure |
a. 0
b. negative (prevents pneumothorax) |
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what is compliance?
what are 3 causes of decreased compliance? |
change in lung volume for a given change in pressure
pulmonary fibrosis, insufficient surfactant, pulmonary edema |
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Hb
how many subunits |
4 polypeptide subunits (2 alpha, 2 beta)
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2 forms of Hb and what are their affinities for O2
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T = taut, low affinity
R = relaxed, high affinity (300x) (When you're relaxed, you do your job better - carry O2) -positive cooperativity, negative allostery (unlike myoglobin) |
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5 things that shift Hb from R to T form?
what does this do to the dissociation curve of oxygen? |
Cl, H, CO2, 2,3BPG, temperature
shifts dissociation curve right --> decreases O2 affinity --> increases O2 unloading |
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How does fetal Hb compare to adult Hb
a. in structure b. affinities |
a. fetal has 2alpha and 2gamma subunits
b. lower affinity for 2,3 BPG than HbA --> higher affinity for O2 |
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Methemoglobin
a. what is it? b. what does it bind? c. how do you treat? |
a. oxidized Hb (ferric Fe3+)
b CN, binds O2 less well c. use nitrites to oxidize to methemoglobin (binds CN to allow cytochrome oxidase to function) Then use thiosulfate to bind to CN --> renal excretion treat Methemglobinemia w/ Methylene blue |
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Carboxyhemoglobin
a. what does it bind b. effect |
a. binds CO with 200x greater affinity than O2
b. decrease oxygen binding capacity with a left shift in the oxygen-Hb dissociation curve, decreases unloading in tissues |
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Why does the oxygen-Hb dissociation curve have a sigmoidal shape?
what does it mean if the curev shifts to the right? what does it mean if the curve shifts to the left? |
Hb has positive cooperativity for Hb - affinity increases for each subsequent oxygen molecule bound
right = decreased affinity for oxygen (more unloading) left = increased affitiny for oxygen, (harder to unload) |
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5 factors that cause a right shift in the Hb-oxygen dissociation curve
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Increase in:
CO2 Acid/Altitude DPG (2,3 DPG) Exercise Temperature CADET |
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5 factors that cause a right shift in the Hb-oxygen dissociation curve
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Decrease in CADET
CO2 Acid/Alcohol DPG Exercise Temperature +fetal Hb (higher affinity for oxygen than adult Hb) |
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Pulmonary circulation
a. resistance? b. compliance? |
a. low resistance
b. high compliance |
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What is the effect of a decrease in PAO2 (alveolar oxygen) on lung perfusion
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causes hypoxic vasoconstriction that shifts blood away from poorly ventilated regions of lung to well-ventilated regions of lung
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3 gases that have perfusion limited ventialtion in the lung
what does this mean |
O2, CO2, N2O
gas equilibrates early along the length of the capillary, such that diffusion can increase only if blood flow increases |
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2 gases that have diffusion limited ventilation in the lung
what does this mean |
O2 (emhysema, fibrosis)
CO Gas does not equilibriate by the time blood reaches the end of the capillary |
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Patient has pulmonary HTN
if this progresses, what can it lead to |
cor pulmonale (RVH/dilation) --> RV failure (JVD, edema, hepatomegaly)
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What is the equation for diffusion ventilation of a gas
What is the effect on the equation of emphysema? Pulmonary fibrosis? |
Vgas = A/T * Dk (P1-P2)
A = area T = thckness Dk (P1-P2) = difference in partial pressures emphysema = A decreases pulmonary fibrosis = T increases |
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What is normal pulmonary artery pressure?
Pressure associated with pulmonary HTN? pulmonary pressure associated with exercise? |
normal = 10-14 mmHg
HTN >= 25 >35 mmHg |
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What is the cause of primary pulmonary HTN
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inactivating mutation in BMPR2 gene (which normally functions to inhibit vascular smooth muscle prolferation); poor prognosis
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COPD
Mitral stenosis thromboemboli autoimmune disease L-R shunt sleep apnea living at high altitude common causes of what |
Pulmonary HTN
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How does COPD --> pulmonary HTN
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COPD destroys lung parenchyma = increases resistance
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How does mitral stenosis --> pulmonary HTN
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increases resistance, leading to increased pressure
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How does recurrent thromboemboli --> pulmonary HTN
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decreases cross sectional area
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How do autoimmune diseases --> pulmonary HTN
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inflammation --> intimal fibrosis --> intimal hypertrophy
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How do L to R shunts --> pulmonary HTN
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Increase shear stress --> endothelial injury
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How does sleep apnea or living at a high altitude --> pulmonary HTN
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hypoxic vasoconstriction
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If pulmonary HTN is left untreated, what does it cause?
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severe respiratory distress --> cyanosis and RVH --> death from decompensated cor pulmonale
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What is the formula for pulmonary vascular resistance
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PVR = [(pulm. artery pressure) - (P left atrium or wedge)] / CO
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equation for vascular resistance?
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R = [8(viscosity)(length)]/[(pi)(r^4)]
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Oxygen content of blood
how do calculate What is the normal level of O2 binding capcity? |
O2 content = O2 binding capacity * % saturation + dissolved O2
O2 binding capcity = 20.1 mL O2/dL |
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1g Hb holds how much O2?
How much Hb is in blood? Cyanosis occurs when deoxygenated Hb reaches what level? |
1.34mL O2
normal Hb amount is 15 g/dL >5g/dL |
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Oxygen content of blood
how is it affected if Hb falls |
oxygen content of blood decreases overall, but not % sat or dissolved O2
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Oxygen content of blood
what is the effect of chronic lung disease |
arterial PO2 decreases because physiologic shunt decreases the O2 extraction ratio
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How do you measure oxygen delivery to tissues
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CO * oxygen content of blood
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What is the alvoelar gas equation
How can it be approximated |
PAO2 = PIO2 - (PACO2/R)
PAO2 = 150 - (PACO2/0.8) R = respiratory quotient = CO2 produced / O2 consumed |
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What is the A-a gradient?
what are 3 causes of its increase? |
A-a gradient = PAO2 - PaO2 = 10-15 mmHg
increases in hypoxemia (shunting, V/Q mismatch, fibrosis = diffusion block) |
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Oxygen deprivation
Hypoxemia (low PaO2) 5 causes |
High altitude, hypoventilation (normal A-a gradient)
V/Q mismatch, diffusion limitation, R-L shunt (A-a increase) |
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Oxygen deprivation
Hypoxia (decreased O2 delivery to tissue) 5 causes |
low CO
hypoxemia anemia CN poisoning CO poisoning |
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Oxygen deprivation
Ischemia (loss of blood flow) |
Impeded arterial flow
Reduced venous drainage |
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V/Q
How does the apex of the lung compare to the base of the lung |
apex: V/Q = 3 (wasted ventilation)
base: V/Q = 0.6 (wasted perfusion) both V and Q are greater at the base of the lung |
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How does exercise affect the V/Q ratio
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Exercise --> increase in CO --> vasodilation of apical capillaries (V/Q approaches 1)
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Where does TB flourish in the lungs and why
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apex - thrives in high O2
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What does it mean if V/Q = 0?
will this improve w/100% O2? |
airway obstruction (shunt)
NO |
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What does it mean if V/Q = infinity?
will this improve w/100% O2? |
blood flow obstruction(physiologic dead space)
YES |
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What are 3 forms in which CO2 is transported in the lungs?
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1. Bicarbonate (90%)
2. Bound to Hb at N-terminus of globin (not heme) as carbaminoHb --> CO2 binding favors taut form (O2 unloaded) 3. dissolved CO2 (5%) |
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Describe the haldane effect
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In lungs, oxygenation of Hb caues a release of H+ --> binds to HCO3 --> H2CO3 --> CO2 and water --> release of CO2
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Describe the Borh effect
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In peripheral tissues, increase in H (from tissue metabolism) --> shift in oxygen dissociation curve to the right --> unloading of O2
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High altitude effect
a. ventilation acutely b. ventilation chronically c. EPO d. 2,3 DPG e. cellular changes f. bicarb g. vessels |
a. acute increase
b. chronic increase c. increase EPO --> high Hct and Hb (chronic hypoxia) d. increase in 2,3 DPG binds to Hb so that Hb releases more O2 e. Increase in mitochondria f. increase renal excretion of bicarb to compensate for respiratory alkalosis (augment by acetazolamide) g. chronic hypoxic pulmonary vasoconstriction --> RVH |
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Response to exercise
a. CO2 production b. O2 consumption c. ventilation rate d. V/Q ratio e. pulmonary blood flow f. pH g. PaO2, PaCO2 h. venous CO2 content |
a. increase in CO2 production
b. increase in O2 consumption c. inc. ventilation rate to meet O2 demand d. V/Q from apex to base becomes more uniform e. Increase flow do to inc. CO f. pH down due to lactic acidosis g. no change h. increase |
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Coal miner's pneumoconiosis
a. type of lung disease b. where in lung does it affect c. 2 possible results |
a. restrictive, interstitial
b. upper lobes c. cor pulmonale, caplan's (rheumatoid arthritis, intrapulmonary nodules on CXR) |
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Type of pneumoconiosis associated with foundries, sandblasting, and mines
shows "eggshell" calcification of hilar LNs dx? path? increases susceptibility to what? |
silicosis (interstitial, restrictive)
silica in upper lobes disrupts phagolysosomes and macrophages, release fibrinogenic factors --> fibrosis TB |
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Type of pneumoconioses
associated with shipbuilding, roofing, plumbing See white, calcified pleural plaques on lower lobes histo: golden brown rods resembling dumbells inside of macrophages dx? associated with what 2 conditions? |
asbestos
bronchogenic carcinoma and mesothelioma |
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stain to see asbestos
what happens once it is enhaled |
Prussian blue
ingested by macrophages |
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What happens in neonatal respiratory distress syndrome?
what is the lecithin/sphingomyelin ratio in the amniotic fluid with this disease? what is the risk associated with persistently low O2 tension |
surfactant deficiency --> increased surface tension --> alveolar collapse
L/S < 1.5 PDA |
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Surfactant
a. type of cells that make it b. when in gestation do they start production |
a. type II pneumocytes
b. 35th week |
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Treatment for Neonatal respiratory distress syndrome? (3)
Why not supplemental oxygen? |
maternal steroids before birth, artificial surfactant for infant, thyroxine
oxygen can result in retinapathy of prematurity |
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Prematurity
maternal diabetes (elevated insulin) cesarean delivery (decreased release of fetal glucocorticoids) risk factors for what? |
neonatal respiratory distress syndrome
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Trauma
Sepsis Shock Gastric aspiration Uremia Acute pancreatitis Amniotic fluid embolism risk factors for what? |
acute respiratory distress syndrome
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Acute respiratory distress syndrome
what causes it? pathologically, what happens? |
damage to alveoli from neutrophilic substances toxic to alveolar wall --> coag cascade or free radicals --> increased alveolar capilllary permeability --> exudate
Hyaline membranes + alveolar fluid |
