Page 402 - Color_Atlas_of_Physiology_5th_Ed._-_A._Despopoulos_2003

V D = dead space [L]; Henderson-Hasselbalch equation
7.
V A = alveolar fraction of V T [L]; (see also pp. 138ff., 379)
–1
f = respiration rate [min ]; a. General equation:
.
–
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V D = dead space ventilation [L · min ]; pH = pK a + log [A ]
.
–1
V A = alveolar ventilation [L · min ]; [AH]
.
V O 2 = O 2 consumption [L · min ]; b. for bicarbonate/CO 2 buffer (37 C):
–1
o
.
V CO 2 = CO 2 emission [L · min ]; [HCO 3 ]
-1
–
FI O 2 = inspiratory O 2 fraction [L/L]; pH = 6,1 +
FE O 2 = exspiratory O 2 fraction [L/L]; α · P CO 2
FE CO 2 = exspiratory CO 2 fraction [L/L]; pH = negative common logarithm of
RQ = respiratory quotient (dimensionless) H activity
+
pK a = negative common logarithm of
d. O 2 consumption and CO 2 emission (organ): dissociation constant of buffer acid in
.
.
–1
V O 2 = Q · avD O 2 [L · min ] denominator (AH or CO 2)
.
.
–1
V CO 2 = Q · avD CO 2 [L · min ] – –
. [A ] and [HCO 3 ] = buffer base concentra-
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Q = blood flow in organ [L · min ] tion; α · P CO 2 = [CO 2]; see Equation 6f. Important Equations in Physiology
avD O 2 , avD CO 2 = arteriovenous
O 2 and CO 2 difference in total circulation 8. Equations for renal function
and organ circulation [L/L blood] (see also p. 150ff.)
e. Fick’s principle: a. Clearance of a freely filtrable substance X
.
CO = V O 2 [L · min ] (C X): . U X –1
–1
avD O 2 C X = V U · P X [L · min ]
–1
CO = cardiac output [L · min ]>
b. Renal plasma flow
f. Gas partial pressure " gas concentra- .
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tion in liquids: RPF = V U · U PAH [L · min ]
0,9 · P PAH
[X] = α · P x [mmol/L plasma]
c. Renal blood flow (RBF):
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[X] = concentration of gas X [mmol · L ]
RPF
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α = (Bunsen’s) solubility coefficient RBF = 1–HCT [L · min ]
[mmol · L –1 · kPa ]
–1
P X = partial pressure of gas X [kPa] d. Glomerular filtration rate (GFR):
.
–1
g. Bohr’s formula (see also p. 115) GFR = V U · U In [L · min ]
P In
(FA CO 2 –FE CO 2 )
V D = V T e. Free water clearance (C H2 O)
FA CO 2
.
V D = dead space [L]; C H 2 O = V U · (1 – U osm ) [L · min ]
–1
V T = tidal volume [L]; P osm
FA CO 2 = alveolar CO 2 fraction f. Filtration fraction
FE CO 2 = exspiratory CO 2 fraction [L/L] GFR
FF = [dimensionless]
h. Alveolar gas equation (see also p. 136) RPF
g. Fractional excretion of substance X (FE X):
PA O 2 = PI O 2 – PA O 2 [kPa] C X
RQ FE X = GFR [dimensionless];
PA O 2 and PI O 2 = alveolar and inspiratory par-
tial pressure of O 2 [kPa] h. Fractional reabsorption of substance X
PA CO 2 = alveolar partial pressure of CO 2 [kPa] (FR X):
RQ = respiratory quotient [dimensionless]. FR X = 1–FE X [dimensionslos];
.
V U = urinary excretion rate [L · min ]
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U X, U PAH, U In = urinary concentration of
substance X, para-aminohippuric acid, and
indicator (e.g., inulin, endogenous crea- 389
tinine) [mol · L ] or [g · L ]
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Despopoulos, Color Atlas of Physiology © 2003 Thieme
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