Download Cumulative Formula Sheet

PHYSIOLOGY FINAL EXAM FORMULA SHEET from JUNG ^^:
NAME
FORMULA
DESCRIPTION
Fick’s Law
Flux = P * A (Cout – Cin)
P = permeability factor
P is a combination of 3 factors
(1) diffusion coefficient (size and shape of substance)
(2) partition coefficient (lipid solubility of substance)
(3) membrane thickness
A = the cross sectional area available for diffusion
C = concentrations of the substance on either side of the separating
membrane
Van’t Hoff Equation
(Osmotic pressure)
π=gCσRT
π = osmotic pressure (atm or mm Hg)
g = number of particles per mole in solution (Osm / mol)
C = concentration (mmol / L)
σ = reflection coefficient
(varies from 0 to 1, where 0 means that the membrane is freely
permeable to that substance; and 1 means the membrane is totally
reflective or impermeable to the substance)
R = gas constant
T = absolute temperature (K)
Nernst Equation
(electrical gradient)
Eion = (RT/zF) In ([ion]0 / [ion]1)
R = gas constant
T = absolute temperature (K)
z F = constant (z = charge)
Starling’s Law of the
capillaries
J = k [(BHP – IFHP) – (BOP-IFOP)]
-the volume of fluid and solutes reabsorbed is almost as large as
the volume filtered
J = fluid movement (ml / min)
k = hydraulic constant (ml / min)
(k depends on permeability of capillaries,
e.g. fenestration)
Cardiac Output
CO = SV * HR
SV = stroke volume
HR = heart rate
Mean Arterial Blood
Pressure (MABP)
MABP =
diastolic BP + 1/3 (syst BP – diast BP)
-MABP is average pressure in arteries (not an arithmetic average)
TPR = total peripheral resistance
MABP = CO * TPR
Poiseuille’s Law
R = 8ηl / (πr^4)
l = length of tube
r = radius of tube
η = viscosity of fluid
Velocity of blood
flow
v=Q/A
-flow decreases when resistance increases
-flow resistance decreases when vessel diameter increases
-properties of the fluid and tube affect resistance to flow
-the flow of fluid through rigid tube is governed by pressure
gradient and resistance to flow
v = velocity of blood flow (cm / sec)
Q = flow (ml / sec)
A = cross – sectional area (cm^2)
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Blood flow
Q = ∆P / R
or ∆P = Q * R
-Q is directly proportional to ∆P and inversely proportional to R
Q = flow (ml / min)
∆P = pressure difference (mm Hg)
R = resistance (mm Hg / ml / min)
Reynold’s number
NR = p d v / η
p = density of blood
d = diameter of blood vessel
v = velocity of blood flow
η = blood viscosity
-NR is used to predict whether blood flow will be laminar or
turbulent
-if value is less than 2,000, blood flow will be laminar, greater
than 3000 – turbulent
Compliance of
blood vessel
C=V/P
-the higher the compliance of a vessel – the more volume it can
hold at a given pressure
Laplace’s Law
Pv = T (1/ r1 + 1 / r2)
for cylindrical vessel, P = T/r
-the force acting on blood vessel wall is proportional to diameter
of the vessel times blood pressure
-relate pressure, radius of vessel, and tension on vessel wall
-the larger the radius, the greater the tension needed to reach a
given pressure (important in capillaries and alveoli)
Pv = ventricular pressure
Boyle’s Law
P1 V1 = P2 V2
(from general gas law PV = nRT )
-as the size of closed container decreases, pressure inside is
increased (inverse relationship)
-special case of the general gas law
-the pressure times volume (at a given t) is constant
(diaphragm movement changes lung volume which changes P)
Laplace’s Law
(again)
P = 2T / r
-critical closing pressure
-note the inverse relationship between pressure and radius
(the greater the radius the lesser the pressure needed to keep the
alveoli open = surfactant effect)
Poiseuille’s Law
(again)
R = 8ηl / (πr^4)
-resistance effects on flow
Dalton’s Law
(PP of O2 & CO2)
Total pressure = sum of all partial
pressures
-the pressure exerted by each type of gas in a mixture
-each gas in a mixture of gases exerts its own pressure
(as if all other gases were not present)
(partial pressures denoted as ‘P’)
atm. pressure =
pO2 + pCO2 + pN2 + pH2O
Henry’s Law
(gas solubility)
clinical application of Henry’s law is
Hyperbaric Oxygenation
-quantity of a gas that will dissolve in a liquid depends upon the
amount of gas present and its solubility coefficient
-breathing compressed air while scuba diving
-breathing O2 under pressure dissolves more O2 in blood
Fick’s Law
(again)
V = (D * A * ∆P) / X
-conservation of mass
-diffusion of gases through the respiratory membrane
Bohr Effect
acidity and oxygen affinity for Hb
-as acidity increases, O2 affinity for Hb decreases
-H+ binds to hemoglobin and alters it
-O2 left behind in needy tissues
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Haldane Effect
transport of carbon dioxide in tissue
capillaries
Hamberger Shift
(Cl shift)
CO2 and Chloride shift
(while exchange of O2 and CO2
occurs in lung and tissues)
Hering-Breuer reflex
inflation reflex
-big deep breath stretches receptors in bronchi and bronchioles
producing urge to exhale
-limits the degree of inspiration and prevents overinflation of the
lungs
Basal Metabolic
Rate
BMR = minimum energy expenditure for
the body to exist
-unit of measurement = cal (1000 cal)
Respiratory Quotient
RQ = CO2 / O2
-RQ is the ration of the volume of CO2 produced to the volume of
O2 utilized
Renal Clearance of a
substance
C=UV/P
-renal clearance of a substance if the volume of plasma that is
completely cleared of the substance per unit time
-urine excretion rate = UV mg / min
U = [substance] in urine (mg/ml)
V = urine flow
P = [substance] in plasma (mg/ml)
Renal Plasma Flow
RPF = C / extraction ratio
extraction ratio (E) = (Pa - Pv) / Pa
-hemoglobin that has released oxygen binds more readily to
carbon dioxide than hemoglobin that has oxygen bound to it
-in tissue capillaries, carbon dioxide combines with water inside
RBCs to form carbonic acid which dissociates to form bicarbonate
ions and hydrogen ions
-if a substance (inulin) is freely filtered:
GFR = C = UV / P
-PAH is almost cleared by glomerular filtration and tubular
secretion
-PAH removed from plasma is known as extraction ratio
Renal Blood Flow
RBF = RPF / (1-hematocrit)
-(1-hematocrit) is the fraction of blood volume occupied by
plasma
Filtration Fraction
FF = GFR / RPF
-FF is fraction of plasma that filters through the glomerulus
Glomerular
Filtration Rate
GFR = Kf * NFP
GFR = Kf * (cap hydr - bowman hydr - cap colloid)
Kf = capillary filtration coefficient
NFP = hydrostatic P + colloidal osmotic P
Good Luck ~ ^.^
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