02b: Spirometry, Transport, Hb Flashcards
Spirometers can be used to measure lung volumes except those that include (X)
X = RV
T/F: minute ventilation can be recorded from spirometry.
True (VT*f)
ERV + IC
VC
IC is measured from end-(inspiration/expiration) of (forceful/relaxed) breathing. And IRV?
IC: end-expiration of VT (relaxed breathing)
IRV: end-inspiration of VT (relaxed breathing)
FVC is obtained when subject, following max (inspiration/expiration), immediately (inhales/exhales) as rapidly, forcefully, completely as possible.
Inspiration;
Expires/exhales
FEV1 is amount of air (inhaled/exhaled) in first (sec/min) of (X).
Exhaled;
Second
FVC
Normal FEV1/FVC ratio:
80% (0.8)
In (restrictive/obstructive) ventilatory pattern, FEV1 and FVC are (increased/reduced) proportionately. How does their ratio change? What’s the problem with lung/airways?
Restrictive; reduced
Ratio unchanged
Lung volume decreased in these cases
In (restrictive/obstructive) ventilatory pattern, FEV1 and FVC are (increased/reduced) disproportionately. How does their ratio change? What’s the problem with lung/airways?
Obstructive (airways obstructed);
FVC decreased or normal; FEV1 decreased to less than 80% normal; ratio decreased to less than 70% normal
T/F: Barometric P varies with altitude.
True
Atmospheric air essentially consists of which gases?
21% O2 and 79% N2
other gases contribute very little
Partial pressure of gas dissolved in liquid: partial pressure in (gas/liquid/solid) phase at which the liquid (gives/takes) it up.
Gas;
Neither gives it up nor takes it up (equilibrated; no net change)
Oxygen carried in blood in which forms? Star the reservoir.
- Dissolved
2. HbO2*
Henry’s law allows calculation of:
Concentration of gas dissolved in liquid = (S*P)
List the Bunsen solubility coefficients of CO2 and O2 at body T.
O2: 0.003
CO2: 0.075
CO2 is (more/less) soluble in water than O2 and (more/less) soluble than N2. Why?
More soluble than both; interacts with polar H2O molecules
More molecules of (CO2/O2) must be dissolved in water to establish equilibrium.
CO2
Gas solubility (increases/decreases) with increasing T.
Decreases
Hb normally present in blood at concentration of (X). One gram of Hb realistically binds (Y) O2.
X = 15 g/100 mL blood Y = 1.34 mL
Hb % saturation is a function of (X). The shape of the plot is (Y) and three key points about it are:
X = PO2 Y = sigmoid
- Flat upper portion (constant arterial O2 saturation)
- Steep slope under PO2 of 40 (allows release of O2 in tissues)
- Arterial blood 98% saturated, only 2% increase available
Hb saturation curve is drawn under specified conditions. List them.
- Hb concentration
- PCO2
- T and pH
Increasing PCO2 changes Hb saturation curve in which way? And increasing PO2?
Shifts entire curve right (Bohr);
No shift, only move up along sigmoid curve
The Hb P(50) is the (X) at which (Y). What’s the normal, physiological value for blood?
X = PO2 Y = Hb is 50% saturation
26 mmHg
The Mgb P(50) is (X) and the HbF P(50) is (Y).
X = 5 mmHg Y = 15-20 mmHg
For comparison: HbA P(50) is 26 mmHg
Which mechanisms are in place to ensure delivery of O2 from blood to muscle and placenta?
Mgb and HbF have significantly higher affinity for O2 than HbA
CO binds Hb with affinity that is (X) times greater than that of O2. Our body produces CO, as a result of (Y), but only (Z)% of our Hb is occupied by it.
X = 240 Y = porphyrin breakdown Z = 1-2
T/F: CO not only binds Hb with high affinity, but also shifts dissociation curve right, preventing proper O2 binding.
False - shifts curves left (O2 can’t unload properly in tissues)
CO2 carried in blood in which forms? Star the ones found in RBC. Double star the ones found in plasma.
- Dissolved
- Bicarbonate
- Carbamino compounds (bound to protein)
All forms found in both RBC and plasma
Carbonic anhydrase catalyzes (formation/breakdown) of (X).
Formation of
X = H2CO3 (from H2O and CO2)
(X) enzyme catalyzes formation of carbamino-Hb.
None; CO2 reacts non-enzymatically with free amino group to form carbamino compounds
Arterial blood: most, (X)% of CO2 is in which form?
X = 90
HCO3-
T/F: Forms of CO2 contributing to gas exchange is in proportion to their amounts in blood (so 90% contribution by HCO3-).
False
CO2 a-v exchange: List the three forms and the respective contribution from each.
- HCO3: 60%
- Carbamino-Hb: 30%
- Dissolved: 10%
The total CO2 concentration is function of (X). The shape of the plot is (Y).
X = PCO2 Y = essentially linear
The locus of the CO2 concentration curve depends on which factor(s)?
Hb saturation;
Haldane effect: lower HbO2 (deoxygenated blood) shifts curve left (more CO2 content for given PCO2)
What’s isohydric shift?
Change in H+ load with no change in pH
In lungs, uptake of O2 aids in (binding/release) of CO2 by its (uptake/release) of protons. Explain.
Release; release;
HbO2 stronger acid than deoxy-Hb, so gives up protons and shifts equation to more CO2 production
In terms of H+ buffering, the (X) group of (Y) AA is crucial. This is partly because (Y)’s effective range of buffering is in which pH range?
X = imidazole Y = histidine
5.7-7.7 (includes physiological pH)
T/F: Hb, with its 4 histidines, has buffer capacity that’s 6x greater than other plasma proteins.
False - has many histidines, not just 4; other fact is true
Quantitative defect in globin subunit production is (SCD/thalassemia).
Thalassemia
SCD mutation is (X). Most common clinical manifestation of SCD is (Y).
X = missense (Glu to Val) in beta chain of HbA Y = vaso-occlusive crisis
HbSC isoelectric point (lower/higher) than HbA, so at given pH, its net charge above its pI is more (positive/negative) and below its pI is more (positive/negative).
Higher;
less negative (closer to 0)
more positive
T/F: Thalassemias associated with low level functional Hb, but normal RBC production/turnover.
False - decreased RBC production and fast RBC turnover (anemia)
(SCD/Thalassemia) associated with marked expansion of ineffective bone marrow.
Thalassemia
Severity of thalassemia depends on:
How many of the 4 alpha or 2 beta genes are missing/silent
(Alpha/beta)-globin pathology is symptomatic in utero.
Alpha
Iron chelation is therapy to treat iron (deficiency/overload).
Overload
Heinz bodies are:
RBC inclusions composed of denatured Hb
T/F: In alpha-thal, Hb cannot be assembled at all.
False - Hb tetramers formed from only beta-chains
Alpha-thal: The Hb is that is formed binds O2 with too (high/low) affinity and no cooperativity.
High
Thalassemia can also result from abnormally long (alpha/beta) globin molecules due to (X) mutation.
Alpha;
X = elimination of stop codon
T/F: Both alpha and beta thalassemias cause precipitation in bone marrow.
False - alpha-thal doesn’t since the Hb tetramers formed from beta globin are soluble (except in old RBCs)
T/F: In beta-thal, Hb cannot be assembled at all.
False - Hb tetramers formed from only alpha-chains
T/F: In beta-thal, the Hb that’s assembled lack O2 binding cooperativity and precipitates.
True
What’s the cause for expansion of ineffective bone marrow in beta-thalassemia?
Excess alpha chains damages RBCs and precursors (anemia)
Major cause of morbidity/mortality in beta-thal is (X) from (increased/decreased) intestinal absorption and transfusions.
X = iron deposits in endocrine organs, liver, and heart;
Increased
T/F: Hereditary persistence of fetal Hb has no deleterious effects.
True
Two most important acquired Hb-pathies are (X).
X = CO poisoning and methemoglobinemia
Smoking can lead to (1o/2o) polycythemia, which is (X). This is a result of chronically (high/low) (Y) levels.
2o;
X = hematocrit greater than 55%
High;
Y = carboxyHb
T/F: Excess CarboxyHb leads to blue-tinted skin, indicative of cyanosis.
False - cyanosis is masked since carboxyHb is cherry-red in color
T/F: Excess MetHb leads to blue-tinted skin, indicative of cyanosis.
True
Congential Methemoglobinemia arises from globin mutations that (X) or (Y).
X = stabilize iron in ferric state Y = impair reduction enzymes (i.e. MetHb reductase)
Acquired Methemoglobinemia arises from toxins that (X), such as (Y).
X = oxidize heme iron Y = nitrate-containing compounds
(X) is a green derivative of Hb and usually induced by (Y). What allows conversion back to normal Hb?
X = sulfHb; Y = drugs
Can’t be converted back
T/F: Sulfhemoglobinemia causes cyanosis at low blood levels.
True
High-affinity Hb-pathy: you’d expect (rise/fall/no change) in hematocrit and blood viscosity.
Rise in both
List three clinical tests that are based on Hb.
- Pulse oximetry
- fMRI
- HbA1c (glycosylated Hb)
Pulse oximeter transmits (X) light, absorbed by (Y).
X = red (660 nm) and IR (940 nm) Y = deoxyHb (red) and oxyHb (IR)
fMRI: There’s a (higher/lower) magnetic field with oxyHb because…
Lower; HbO2 is diamagnetic
Fe is highly magnetic and deoxyHb is paramagnetic (weakly magnetic)
Glycosylated Hb is (reversibly/irreversibly) formed (quickly/slowly) from (X) reacting with (Y).
Irreverisbly; slowly;
X = glucose
Y = N-term of Hb beta chains
HbA1c provides an assessment of (chronic/acute) (hyper/hypo)-glycemia.
Chronic; hyperglycemia
What’s the HbA1c cutoff for diabetes?
6.5% glycosylated Hb
Pulse oximetry: proportion of HbO2 is calculated
from the ratio of (X).
X = 660/940 absorbance