Week 3 Fluids Flashcards
What material has the ability to flow?
Fluids
Give 2 examples of fluids used in anesthesia
IVF
Gases
What is hydrostatics?
The study of fluids that are not moving
Density=mass/volume
Specific gravity
What is hydrodynamics?
The study of fluids in motion
- laminar flow
- turbulent flow
Flow rate=volume/time
Velocity= rate of change of position
Acceleration =rate of change of velocity
What is Pascal’s principle?
Pressure applied to a confined fluid increases the pressure through the fluid by the same amount
What is buoyancy?
The upward force exerted by a fluid that opposes the weight of an immersed object
What is Archimedes Principle?
An object immersed either totally or partially in a fluid feels a buoyant force equal to the weight of the fluid displaced.
If an object floats, is it’s density greater or less than the fluid?
It’s less dense
If an object sinks, what does that mean about its buoyant force?
The buoyant force is less than the true weight of the object
What does it mean about an objects buoyant force if it floats?
The buoyant force greater than the true weight of the object
What is a hydrometer?
Measures specific gravity
Used to determine the density of liquids
What is Bernoulli’s Principle?
Law states that the pressure of a fluid varies inversely with speed. An increase in speed producing a decrease in pressure and vice versa
*The faster a fluid flows, the less pressure it exerts
What is the equation of continuity?
Relates to cross-sectional area of a tube and speed of fluid going through it
The rate at which mass enters a system is equal to the rate at which mass leaves the system, plus the accumulation of mass writhing the system.
When fluid is in motion, it must move in such a way that mass is conserved
What is a Venturi tube flowmeter?
Works based on the Bernoulli effect.
There is a narrowing of the tube, which causes an increase in flow velocity. This decreases the pressure at this site, and causes an uptake of liquid or gas from an inlet at narrow portion of tube
What is viscosity?
A measure of a fluid’s resistance to flow.
Resulting from friction between molecules.
Standard unit of viscosity is: pascal-second
What does Poiseuille’s theorem states that flow rate for a fluid through a tube depends on:
- Radius of the tube
- Length of the tube
- Pressure difference
- Viscosity of the fluid
What is Poiseuille’s Law
Flow of a fluid through a narrow tube varies directly as the pressure and 4th power of the radius of the tube and inversely as the length of the tube and the coefficient of viscosity
What is Reynold’s Number?
For a given liquid and tube there is critical flow rate above which the flow will become turbulent.
- Proportional to viscosity
- Inversely Proportional to density
- Inversely proportional to the radius of tube
More dense would be lower Reynolds number
What is specific gravity?
Ratio of an objects density compared to the density of H2O
H2O specific gravity=1.0g/ml
What are the states of matter?
Solid
Liquid
Gas
What are solids?
- have a definite volume and shape
- molecules are closely packed together
- intermolecular forces are strong enough to hold molecules rigidity in place with respect to each other
What are liquids?
- have a definite volume but no definite shape
- intermolecular forces are strong enough to hold molecules in a condensed phase
What are gases?
- have neither definite shape nor volume
- are ideally independent molecules
- intermolecular forces are essentially zero between molecules
What is kinetic-molecular theory of matter?
Attempts to describe all states of matter and the conversion between states
What are ionic bonds?
Results from attraction between oppositely charged ions
VSEPR
Electrons repel each other
What is the valence bond theory?
Covalent bond results from overlap of 2 electron clouds
What if electronegativity?
The tendency of an atom in a molecule to attract shared electrons to itself
What are intermolecular forces?
These are attractive forces between molecules or atoms
What are London forces?
AKA: van deer waal’s forces
Are created by instantaneous dipoles
What are effects of intermolecular forces?
More intermolecular forces mean
- higher boiling and melting points
- higher heats of fusion and vaporization
- lower vapor pressure
- more viscous fluids
- important for medications and solubility
- like dissolves like
What is surface tension?
The tension of the surface film of a liquid caused by the attraction of the particles in the surface
-substances with greater intermolecular attractions have greater surface tensions
What is the the Law of LaPlace?
The surface tension on a fluid depends not he pressure of the fluid and the radius of the fluid’s container or shape.
- the tension on the surface of the blood vessel is directly proportional to the radius of the vessel
- as radius gets bigger, wall tension gets bigger
Large blood vessel will have more wall tension than capillary (if BP constant)
What is vapor pressure?
The pressure exerted by molecules that escape from a solid or liquid sample into the gas phase
-temperature increases vapor pressure
What is dynamic equilibrium?
Describes a system in which the components of a system are allowed to change states, but the overall composition of the system is static.
-as many coming out into a liquid and vise versa
What is boiling point?
The temperature at which the vapor pressure of a liquid equals ambient pressure
What is volatility?
The tendency of a liquid to evaporate
*des is most volatile gas we use
What is vaporization?
The equilibrium process of a liquid converting into a gas. The opposite of condensation
What are the various names for changes of state?
- solid to liquid: melting
- liquid to solid: freezing
- liquid to gas: vaporization
- gas to liquid: condensation
- solid to gas: sublimation
- gas to solid: deposition
What are covalent bonds?
Result from sharing one or more pairs of elections
What are micelles?
Tails that dissolve in each other forming a sphere. Creates a non-polar microenvironment in water
