Physics And Math Flashcards
Molecular theory of matter
States that matter is made of minute particles called molecules that exists in liquid, solid, and gaseous states
Kinetic theory of matter
Molecules are in constant random motion and have a degree of attraction between them called van der waals forces
Critical temperature
Temp above which a gas cant be liquefied regardless of how much pressure is applied
Avogadros hypothesis
If you have 2 diff containers containing 2 diff gases at same temp and pressure then they contain same number of molecules
One mole is what
One gram multiplied by molecular weight
One mole occupies what volume
22.4 l
Calibration of vaporizers done using what
Avogadros hypothesis. Sevo weighs 200, so 200g sevo is 1 mol and occupies 22.4 l
Bowles law
PV
Charles law
V/T
Bowles law
Volume of an ideal gas is inversely proportional to the pressure
V= 1/P
Application of Boyles law
Reservoir bag. Applying pressure causes volume to decrease
How boyles law applies to spontaneous breathing and bellows
When intrapulmonary pressure becomes negative, intrapulmonary volume increases
As pressure increases the volume in the bellows decreases
Charles law
Volume is directly proportional to temperatiure.
V/T (kelvin)
Gay lussacs law
At a constant volume the pressure of a gas sample is directly proportional to the kelvin temperature
Application of gay lussacs law
Full cylinder moved from 70 to 100 degrees f. What happens to p
P increases
Constants for the gas laws
Pressure, charles
Temperature, boyles
Volume, guy lussacs
How ideal gas law applies to cylinders
As compressed gas empties, pressure falls. Cylinder has constant vol, the moles decreases as gas exits, so pressure decreases
Daltons law
Total pressure of a gas in a mixture is the sum of the partial pressures of each gas
Daltons law states that in a mix of gases the pressure of each is gas ____ as what it would exert if it alone occupied the container
Same
What is ficks law of diffusion
rate of diffusion of substance across a membrane is r/t: concentration gradient, surface area of a membrane, solubility, thickness of membrane, molecular weight
How diffusion r/t: Concentration gradient Surface area Solubility Thickness of membrane Molecular weight
Directly Directly Directly Inversely Inversely
Vgas=
Area x solubility x partial pressure difference
/
Molecular weight x distance
Clinical applications of ficks law
2nd gas effect
Uptake of high vol n20 concentrates remaining 2nd gas
Diffusion hypoxia
What is 2nd gas effect
High inspired conc of n20 accelerates uptake of a companion gas (ficks law)
How ficks law r/t concentration
Uptake of high volumes of n20 concentrates the remaining 2nd gas
Diffusion hypoxia
Diffusion of gases across the alveolo capillary membrane
How ficks law r/t transfer of air pockets, ett cuff, and drug transfer
- When n20 in use, 34x more soluble in blood than n2, vol n20 in > than n out
- Ett cuff expands when n20 in use
- Placental transfer of drugs and o2
Grahams law
A gas diffuses at a rate that’s inversely proportional to sq root of its molecular weight
As molecular weight increases what happens to diffusion
Decreases
What is Henry’s law
Amt of gas dissolved in a liquid is directly proportional to the partial pressure of the gas in contact w the solution
Constants for co2 and o2
O2= .003 ml/100mlblood/mmHg partial pressure CO2= .067ml/100mlblood/mmHg partial pressure
How do you estimate pao2 using Henry’s law
Multiply fio2 by 5
Critical temp
Temp above which a substance goes into gaseous form in spite of how much pressure is applied
A gas cant be liquefied if ambient t is ___ than critical temp
Greater
A gas can be liquified if sufficient ___ applied at ambient temp ___ the critical temp
Pressure, below
Critical temp of 02
-119 degree c
O2 cant be liquified at __ __ no matter how much pressure applied
Room temp
A gas can be liquified if sufficient pressure applied at ambient temp ____ critical temp
Below
Critical temp n20
39.5 degree c
Temp of n20 at room temp
25 degree c
Pressure ___ be applied to liquefy n2o at room temp
Can
What is adiabatic cooling
Occurs when matter changes phase. Implies change in temp of matter w/o gain or loss of heat
What applies to n20 cylinder regarding adiabatic cooling
When n20 opened fully frost can form at outlet due to cooling
Joule thompson effect and example
Expansion of a gas causes cooling
As gas leaves a cylinder the expansion cools surrounding air causing condensation on cylinder
What is poiseuilles law applied w laminar flow
Relationship of rate of flow and: pressure gradient across length of tube (direct), radius^4 of the tube (d), length of tube (inverse), viscosity of fluid (i)
Poisuilles eqn
Q (flow) = pi x r^4 x change P / 8 n (viscosity) x l (length of tube)
What does poisuilles law apply to
Iv flow (large bore)
Airways (large ett_
Vascular flow (polycythemia and anemia)
Thorpe tubes- at low flows
Viscosity
Determinant of flow when flow is laminar (low flow rate)
How does density impact flow
When flow is turbulent. Density= mass/vol. determines rate of flow in flow meters when rate of gas flow high through variable orifice flow meter. Ex Helios
How to calc reynolds number
Velocity x density x diameter
/
Viscosity
When reynolds flow = turbulent
Greater than 2000
Thorpe tube determinants
At low flows- annular orifice tubular- flow governed by viscosity
At high flows- wider top of float- more of an orifice- density governs flow
Factors that change flow from laminar to turbulent
Increased velocity
Bend >20 degrees
Irregularity in tube
Bernoullis theorem relates what
Pressure and velocity. Lateral wall pressure is least at pt of greatest constriction and speed is greatest.
Flow faster through constricted pts, slower at wider pts
Narrow diameter= __ lateral wall pressure= __ speed
Decreased
Increased
Wider diameter= __ lateral wall pressure = __ speed
Increased,
Decreased
How bernoulli relates to venturi tubes
As fluid goes through narrow pts, velocity increases, pressure drops
Velocity of fluid can be found by measuring pressure
3 ex of bernoulli in constricted tube with subatmospheric p and sidearm used to aspirate fluid
Nebulizers
Venturi o2 masks (24-40% o2)
Jet ventilation
What is beers law
Beer part
Absorption of radiation by a given thickness of a solution of a given concentration is the same as 2x the thickness of a solution 1/2 the concentration (beer)
What is lambert part of beers law
Each layer of equal thickness absorbs an equal fraction of the radiation that passes through it
How pulse ox works
2 led lights. One red emits 660 nm light (detects deoxyhgb). One infrared emits light at 940 nm (oxyhgb). Measures absorption
Errors in pulse ox
Artifact (ambient light, low perfusion, motion)
Alternate species of hgb (carboxy, etc)
Polycythemia (no effect)
Methylene and Isosulfan (false low)
Indocyanide green and indigo carmine (slight decrease)
Blue nail polish- low
How carboxyhgb Methgb Hgbf Hgbs Effect pulse ox
False high
Sat >85 false low, sat <85 false high
No effect
No effect
Law of la place
Pressure gradient against wall of a sphere or tube/cylinder (vessel, ventricle, alveolus) r/t wall tension directly and radius inversely
T= pr
Wall tension increases with vessel ___
Radius
Applications of la places law
- Normal alveoli and need for surfactant in expiration
- Vascular pathology- aneurysm rupture d/t inc wall tension
- Ventricular vol and work of heart- dilated ventricle has more tension in wall (end diastolic p rises)
Ohms law
Resistance that allows one ampere of current to flow under the influence of a potential of one volt
W (resistance)= volt (potential) / current (ampere)
Or e (volt)= i (amp/current) x r (resistance)
Clinical applications of ohms law
Strain gauges in pressure transducers
Thermistors
4 impacts of electricity in or
- Metal bed- bleeding- electrical equip- burn risk to pt
- Macro shock: current thru body from faulty wiring, improper grounding
- Microshock: current in or near heart from pacing wires or fault of equipment in cardiac cath
- Electrocautery
Macroshock s/s from 1 ma 5 10-20 50 100-300 6000
Skin tingling Max harmless current Let go source Pain, loc, mechanical injury V fib, resp intact Complete physiologic damage
Microshock
50-100 ma leads to what
Vfib
Macroshock Skin tingling Max harmless current Let go source Pain, loc,mechanical injury V fib, resp intact Complete physiologic damage
1 ma 5 10-20 50 100-300 6000
Microshock
for vfib
50-100 micro amps
How to calc
2% lidocaine
What it equals
How many mg per ml
2 gms in 100 ml
20 mg 1 ml
1% lidocaine
1 ml= how many mg
1%= 1 gm per 100 ml
1000 mg in 100 ml
10 mg in 1 ml
0.75 bupivicaine
How many mg in 1 ml
0.75 g per 100 ml
750 mg in 100 ml
7.5 mg in 1 ml
Grams per __ c
1:100,000 epi
1 g
1:100000 epi
Conc in 1 ml
1 g in 100000 ml 1000 mg in 100000 ml 1 mg in 100 ml 1000 mcg in 100 ml 10 mcg in 1 ml
1:1000 neostigmine = what per ml
1 g 1000 ml
1000 mg in 1000 ml
1 mg per ml
Epi 1:10,000
How many mg per ml
1 g in 10,000 ml 1000 mg in 10,000 ml 1 mg in 10 ml 1000 mcg in 10 ml 100 mcg per ml Or 0.1 mg per ml
Epi 1:200,000
How to calc mcg per ml
1 g 200,000 ml 1000 mg per 200,000 ml 1 mg per 200 ml 1000 mcg per 200 ml 10 mcg per 2 ml 5 mcg per ml
2% lidocaine w epi 1:200,000
What is in each ml
2%= 2 g per 100 ml
2000 mg per 100 ml= 20 mg per ml
1:200,000 means 1 g per 200,000 ml. 5 mcg per ml
