Chapter 54: Physical Principles Flashcards
May be a pure element, in which atoms are the same, or a compound of different atoms
Molecule
Explains that there are three states of matter
Molecular theory
State of matter with a condensed structure in which strong intermolecular bonds determine a definite shape and volume
Solid
State of matter composed of molecules that move freely, have no definite volume, and are without definite shape
Liquid
State of matter that is compressible and completely fills an enclosed space
Gas
State of matter with strong intermolecular bonds
Solid
State of matter that is dense than gases and are fluid
Liquid
State of matter with weak intermolecular bonds and are fluid
Gas
A hot ionized gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons. Often considered a fourth state of matter
Plasma (ex. sun, lightning)
Units of measurement
Lenth - Meter - m
Mass - Kilogram - kg
Time - Second - s
Temperature - Kelvin - k
Force - Newton - N
Pressure - Pascal - Pa
Work - Joule - J
Frequency - Hertz - Hz
Common unit of measurement for pressure for gases
cm H2O
Common unit of measurement for pressure for liquids
mm Hg
A dot over a symbol represents
The rate of change (distance over time or velocity)
The amount of a substance, determined by the number and type of molecules
Mass
The measurement of the pull of gravity on an object
Weight
Measured on a scale
Weight
Measured by using a balance comparing a known amount of matter to an unknown amount of matter
Mass
A mechanical energy applied to the body. The product of mass times acceleration
Force (F = m x a)
Describes the force due to to the acceleration of gravity acting on a mass. Mass times gravity
Weight (W = m x g)
A force applied to an area
Stress
Force applied at an angle
Shear stress
(Force per area) is the same concept applied to fluids, including gases.
Pressure (P = F / A)
Pressure generated by the weight of atmospheric gas above the barometer at any altitude. Drops when there is an increase in elevation
Atmospheric Pressure
The physical deformation of a structure, usually caused by stress
Strain
The reversible deformability that can be generated by stress, yet, it returns to its original form
Elasticity
State of matter that is highly elastic and can be compressed relatively easily
Gas
State of matter that is less elastic and behaves as if it is incompressible
Liquid
The resistance to movement between adjacent fluid molecules
Viscosity
State of matter that lacks elasticity
Solid
Term for when the weight of a fluid generates static fluid pressure due to the force gravity
Hydrostatic Pressure
Fluid exits capillary since capillary hydrostatic pressure is greater than blood colloidal osmotic pressure
Filtration
No movement of fluid since capillary hydrostatic pressure is the same as the blood colloidal osmotic pressure
No net movement
Fluid re-enters capillary since capillary hydrostatic pressure is less than blood colloidal osmotic pressure
Reabsorption
Hydrostatic Pressure equation
P = h x p x g
P = Pressure
h = height
p = density
g = acceleration of gravity
Volume change caused by pressure change/stiffness of sphere
Compliance
Reciprocal of compliance. Returns to its original shape
Elastance
Law stating that at equilibrium, pressure is constant throughout the fluid, if the pressure caused by the weight of the fluid is neglected. Ignores hydrostatic pressure
Pascal’s Law
Law that describes the tension of the wall of a sphere or cylinder. Wall tension increases with radius. A smaller structure generates a greater inward pressure, resulting in a tendency to collapse due to surface tension
Laplace’s Law
T = (P x r) / 2
P = (2 x T) / r
T = Tension
P = Pressure
r = Radius
The tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area.
Surface Tension
The amount of heat, or thermal energy, present in a system.
Temperature
Reduces surface tension. Reduces the pressure required to expand an alveolus. Also reduces the pressure differences between alveoli of different diameters
Surfactant
Temperature Scales
Absolute Zero:
F = -460
C = -273
K = 0
Oxygen Boils:
F = -297
C = -183
K = 90
Water Freezes:
F = 32
C = 0
K = 273
Normal Body Temp:
F = 98.6
C = 0
K = 310
Water Boils:
F = 212
C = 100
K = 373
Fahrenheit to Celsius Conversion
C = (Fahrenheit degrees - 32) x 5/9
Celsius to Fahrenheit Conversion
F = 32 + (Celsius degrees x 9/5)
Changes in the thermal state of a system by adding or removing energy, such as when changes in pressure, volume, or temperature alter the state of a substance
Thermodynamics
A change of state which requires the addition of energy (heat)
Endothermic
A change of state which requires the release of energy
Exothermic
Exothermic change from gas to a liquid or solid
Condensation
Exothermic change from liquid to a solid
Freezing
Endothermic change from a solid to a gas
Sublimation
Endothermic change from a solid to a liquid
Melting
Endothermic change from a liquid to a gas
Evaporation
Defines the relationship between pressure, volume, temperature and the number of molecules of a gas. Pressure and volume are inversely related, whereas temperature is directly proportional to volume or pressure
Ideal Gas Law
(P1 x V1) / T1 = (P2 x V2) / T2
P = Pressure
V = Volume
T = Absolute Temperature
PV = nRT
P = Pressure
V = Volume
n = Number of Moles
R = Gas Constant
T = Absolute Temperature
Law stating that volumes of gases combine chemically in volumetric proportions that are small whole numbers
Gary-Lussac’s Law of Combining Volumes
V = k x n
V1 / n1 = V2 / n2
V = Volume
k = Constant
n = Number of Moles
Law states that pressure is inversely proportional to volume. If the volume of a gas is halved, pressure will double, given a constant mass and temperature
Boyle’s Law
P x V = k
P1 x V1 = P2 x V2
P = Pressure
V = Volume
k = Constant
Law that predicts the effect of temperature on a fixed amount of dry gas. As the temperature increases, the volume increases because the faster molecules collide harder and push each other farther apart.
Charles’s Law
V = k x T
V1 / T1 = V2 / T2
V = Volume
k = Constant
T = Absolute Temperature
Law that describes the direct relationship between pressure and temperature given a fixed mass and volume of gas
Gary-Lussac’s Law of Pressure and Temperature
P = k x T
P1 / T1 = P2 / T2
P = Pressure
k = Constant
T = Absolute Temperature
Law that describes the behavior of physical mixture of gases and vapors
Dalton’s Law of Partial Pressures
Pressure of Oxygen at 1 Atmosphere
PIO2 = FIO2 x Patm
PIO2 = 0.21 x 760 mm Hg = 160 mm Hg
PIO2 = Partial Pressure of inspired oxygen
FIO2 = Fraction of Oxygen in inspired gas
Patm = Atmospheric Pressure
Composition of Dry Air
Nitrogen = 78.08 %
Oxygen = 20.95 %
Carbon Dioxide = 0.03 %
Argon = 0.93 %
Trace Gases = 0.01 %
Calculation of Absolute Humidity
(16.42 - 0.73 x T) + 0.04 x T2
T = Temperature (Celsius)
Calculation of Relative Humidity
(Absolute Humidity / Humidity Capacity) x 100%
Calculation of Humidity Deficit
Content - Capacity at 37 degrees Celsius = Content - 43.8 mg/L
Calculation of Body Humidity
(Content/Capacity) x 100% = (Content/43.8 mg/L) x 100
The measurement of the actual amount of water vapor in the air or the mass of water present in a volume of gas, usually measured in milligrams per liter. Can be measured by weighing the water vapor extracted from air using a drying agent, or using meteorological equipment
Absolute Humidity
