2 - Physics Flashcards
What is an ion?
Atoms that has gained or lost an electron from their natural composition
What is atomic mass number?
sum of protons and neutrons
What is an isotope?
same number of protons but different number of neutrons. Same charge, different atomic mass
What is a covalent bond?
Sharing of electrons between atoms
Ion to Ion bonds are electrostatic or covalent?
strongest of the electrostatic
Molecules with ionic bonds having _____ melting and boiling points
high
What is an isomer?
Molecules with the same number and type of atoms and bonds but different structure
Energy is _____ when a bond is formed, and ______ when a bond is broken
released
consumed
If energy is consumed when a bond is broken, why does ATP conversion to ATP produce energy?
Energy is actually consumed in the process of breaking an ATP bond, but a greater mount of energy is released when the free phosphate form news bonds with hydrogen
Enthaply
total of all kinetic and potential energy possessed by a system
Graham’s Law
rate of gas diffusion through an orifice is inversely proportional to its molecular weight
This is why smaller molecules (with lower molecular weight) diffuse quicker than large molecules (with higher molecular weight)
Fick’s Law of Diffusion
Diffusion of a gas across a semipermeable membrane is directly proportional to the partial pressure gradient, the membrane solubility of the gass, the membrane area
Inversely proportional membrne thickness and molecular weight of the gas
ALLOWS DETERMINATION OF GAS EXCHANGE
Newton’s First Law
Inertia
A body in motion tends to stay in motion
Newton’s Second Law
Vectors
Newton’s Third Law
Law of reciprocal action
For every action there is an equal and opposite reaction
Force
Force= mass x acceleration
The amount of energy required to move an object
What is a newton?
The force required to accelerate 1 kg of weight 1 m/sec
Equivalent to 1/9.81 kg (102g)
What is a dyne?
1/1000th of a newton
used to measure force when newtons are too large a unit to be useful (SVR)
What is pressure?
Force over area
F/a
The smaller the area to which a set force is applied, the ______ the pressure
higher
What is the standard unit of measure for pressure?
Pascal (Pa)
the force of 1 newton over 1 square meter
Pa=1N/1m²
What is atmospheric pressure?
Cumulative effect of gravity on atmospheric gases
Atmospheric gases are _____ concentrated at altitude and ______ concentrated at sea level
less
more
1 atm is the same as:
x mmHg
x torr
x kPa
760
760
100
What is a manometer?
liquid filled tube that is open to atmospheric pressure on one end and exposed to a pressure for measurement on the other end
What is temperature?
Average kinetic energy of the particles in a system
How do you convert celsius to kelvin?
Celsius and Kelvin are the same size units, so you only have to adjust for zero point
K = C + 273.15
What is the ideal gas equation?
PV = nRT
n = moles
What is an ideal gas?
No intermolecular forces
Molecules occupy no microscopic value
All collisions are perfectly elastic
What is the gas constant (R) ?
R = PV/nT
0.0821 (with atm and L)
What is Boyle’s Law?
Pressure is inversely proportional to volume
P¹V¹ = P²V²
Can calculate the change in pressure if there’s a change in volume, assuming temperature remains the same
Charles’s Law
Volume increases directly with temperature
(If pressure is allowed to stay the same)
V¹/T¹ = V²/T²
Avogadro’s Law
The number of moles varies directly with the volume
For 1L of gas, there will be 0.4m of gas particles
1 mol of gas particles is always equal to 22.4L gas
V¹/V²= N¹/N²
Avogadro’s Number
6.02 x 10²³
Entropy
the movement of energy from a high concentration to a low concentration
Universal trend toward equilibration
What is adiabatic change?
Rapid change expansion or compression of gas that exceeds the speed of energy equilibration with the surrounding environment
entails no increase or decrease in the system’s energy
What is Adiabatic energy concentration?
compressing a gas quickly intensifies the kinetic energy so that the temperature is higher
Because there is no communication with the environment (pressurizing a tank of oxygen with rigid walls and valves) the same amount of energy is in the system, even though the temperature is higher
What is adiabatic energy dilution?
lowering the pressure quickly lowers the temperature, but not the total energy
If you open an oxygen outlet rapidly what kind of change takes place?
Slowly?
Adiabatic
Isothermal
Poiseuille’s Law
Think IV catheter size
States that radius has the greatest effect on flow
A tripling of the radius has an 81-fold increase in flow
Entire equation includes viscosity, pressure gradient, length and radius of the tube
When is turbulent flow present in the airways?
medium to large airways
peak flow
coughing
phonation
What is the Reynold’s Number used for?
Determining the presence of laminar, turbulent, or transitional flow
Reynold’s Number Equation
Reynold’s = velocity x diameter x density viscosity
Giving helium to asthmatic patients is an example of what concept?
Laminar Flow/Reynold’s Number
Helium has a lower density, so when inhaled creates laminar flow through a diminished radius
Bernoulli’s Principle
Describes the effect of fluid flow through a tube containing a constriction
As flow passes through a narrowing in the tube, velocity of the flow increases, which decreases the pressure at the area of the constriction
How do you calculate the velocity of a flow rate?
Flow (units/time) divided by area
Venturi Effect
Utilizes the bernoulli principle
Air may be entrained into a flow of liquid, or a liquid may be entrained into the flow of a gas
Laplace’s Law
Relationship of wall tension to pressure and radius
Cylinders: T = Pr
Spheres: 2T = Pr
Using Laplace’s Law, does an aneurysm (increased radius) have a higher or lower tension?
Higher tension! So an increase in SBP will affect the aneurysm much more than the artery
How does Laplace’s Law apply to alveoli?
the smaller the sphere, the higher the tension on its walls. So gas will move from the small sphere to the larger one. Without surfactant to equalize the surface tension of small and large alveoli, they small ones completely collapse and the large ones become overdistended
