Module 1 The Physical Principles of Respiratory Care Flashcards
Which gasses do RTs care about?
Oxygen, Nitrogen, Hydrogen, Neon, helium, and Carbon.
Which other solids, liquids, or gasses are also important to Respiratory therapists?
Sodium, Chloride, and Potassium.
(only in their ion/electrolytic form).
What are the equations for:
Force = Newtons
Pressure = Pascals
Work = Joules
Energy = Joules
Power = watts
Density?
specific gravity?
Force = Mass * Acceleration = Kg*M/Sec^2
Pressure = Force/Area = N/m^2
ForceDistance = Nm
Power = Work/Time = Joules/sec
Energy has 2 equations (potential and kinetic energy)
PE = Massgravityheight
KE = 1/2Mass^V^2
Velocity is acceleration x time = m/sec2 * sec = m/s
density = basically always divide by 22.4
specific gravity = divide by 1.28
One atmosphere of pressure equals:
760 mmHg
76 cmHg
29.9 inHg
33.9 ftH2O
1034 cmH2O
1034 g/cm2
101.3 kPa
101,300 Pascals
14.7 pounds/square inch (psi)
Insert image later.
Why is a water column (cmH20) not commonly used ? and where would it be used?
A water column not practical, water is not very dense so a very large amount of water would be needed if values got too big.
It would most likely be used to measure pressures in the lung.
does atmospheric pressure change as we increase altitude?
Yes, as we get closer to earth more pressure is being put down because of gravity. as we go up, air pressure drops. Gasses are attracted to the surface of the earth because of gravity.
Pressure in liquids is a little different, would pressure be higher at the top or bottom of a liquid?
Hint - P = HDG
The pressure would be greater at the bottom. Pressure in liquids relies on height of liquid, density of liquid, and gravity.
Pressure remains the same at any depth regardless of container shape
Gauge pressure vs Absolute pressure?
Gauge pressure doesn’t take ATM pressure into account (air around the earth that is putting pressure onto object)
ABS pressure does. I think ABS pressure is literally + or - 1 in this course.
what is the cardinal concept for “Work”?
All forces need to be applied to the same direction.
if there is also movement up and then right, there is no work on the OBJECT.
5 states of energy?
Heat, mechanical, nuclear, light, and chemical
How can Newtons 3 Laws of motion simply described as?
- inertia, moving things keep moving Things at rest, stay at rest.
- F = Mass * Acceleration. More force makes more acceleration. More mass means loss of acceleration.
- Action - Reaction. If an object exerts a force on a second object. The second object exerts an equal force on the first.
Hooke described the properties of elastic recoil.
A material is said to be elastic if it will regain its length or shape after the removal of the force that caused the material to change length or shape.
Elastic Limit
Each material or object will have a limit that it can be changed above which it will not return to normal
Given these terms: Does stretch have an direct relationship with direct force?
Yes, to a certain limit.
Hookes law = F (deforming force) = Kx (proportion constant x amount of stretch)
therefore, if the distorting force is doubled, then the amount of stretch is also doubled, to a certain limit
What is the law of Mass action?
hint A + B <–> C + D
When 2 or more substances react, 1 or more different from the original 2 will form
The rate of reaction is proportional to the concentration of the reactants.
air is made up of 21% oxygen, aside from trace gasses, what is the remainder?
79% is nitrogen or N2
States of matter: what are some characteristics of Gases
Weak attractive forces
Lack restriction to their movement
Rapid, random motion and frequent collisions
Ability to flow
somewhat like a liquid and as a result gases can also be described as fluids
Very easily compressed or expanded
Greatest amount of Kinetic Energy (potential energy is minimal)
States of matter: what are some characteristics of Solids?
Maintain shape
Kept in place by strong
attractive forces
Not easily compressed
Least amount of Kinetic
Energy (most of the energy is Potential Energy)
States of matter: what are some characteristics of liquids
Still strong attractive forces
Molecules can move more freely (this is why they take the shape of their containers)
Able to flow (thus called fluids)
Like solids, they are still quite dense and are not easily compressed
Which state of matter has the most/least amount of Kinetic Energy? Potential Energy?
Most amount of KE is gases, least is Solid
Most amount of PE is solid, least is Gas
Definition of boiling/condensing?
Each substance has a temperature at which it will change from a liquid to a gas (or reverse, condensing).
Definition of Melting/Freezing?
Most substances have a specific temperature point where they will change from a solid to a liquid (or reverse, freezing).
What are 2 types of Phase Changes?
Exothermic - releases energy
Endothermic - absorbs energy.
Definition of Evaporation/Sublimation
When water (or other) undergoes a phase change from a liquid to a gas, below its boiling point it is called evaporation.
When a solid changes directly to a gas it is sublimation
The rate of evaporation increases with an increase in temperature, surface area or a decrease in pressure
Are Evaporation and Condensation important to our patients?
Evaporation and Condensation are very important to breathing. Delicate balance between evaporation and condensation so that the airway does not dry out.
difference between gas and vapour?
Gasses exist at temperatures above the substances critical temperature
Vapour
is a form of gas that is below its boiling point and/or its critical temperature
Bonus info:
Vapour pressure increases with temp.
Decrease temp—dew point
Head pressure over a liquid surface.
When vapour pressure in the liquid increases to match atmospheric—you have boiling.
Bpoint is decreased at elevation.
Ravioli in micro wave
