Chemistry and physics 3 Flashcards
Bernoulli’s principle describes the relationship between
the pressure and velocity of a moving fluid (or gas)
If the fluid’s velocity is ________, then the pressure exerted on the walls of the tube will be _______
high; low
The Venturi effect is an application of the
Bernoulli principle
As airflow in a tube moves past the point of constriction, the pressure
at the constriction decreases (Bernoulli principle)
If the pressure inside the tube falls below atmospheric pressure, then the air is
entrained into the tube (Venturi effect)
Clinical applications of the Venturi effect include
a jet ventilator
venturi mask
nebulizer
The Coanda effect describes how a
jet flow attaches itself to a nearby surface and continues to flow along that surface even when the surface curves away from the initial jet direction
A clinical example of the Coanda effect is a
wall-hugging jet of mitral regurgitation
When applied to the left ventricle, which variables are included in the law of Laplace? (select 2)
a. wall tension
b. wall thickness
c. transmural pressure
d. diameter
a. wall tension
b. wall thickness
In spheres and cylinders, the law of Laplace illustrates the relationship between the
wall tension
internal pressure
radius
The surface tension of a sphere equation is
tension= (pressure x radius)/ 2
Examples of surface tension of a sphere include
alveolus
cardiac ventricle
saccular aneurysm
The surface tension of a cylinder is
tension= pressure x radius
Examples of surface tension of a cylinder include
blood vessels, aortic aneurysm
Pressure is a ______ force
pushing force; it pushes the walls of the object apart
Tension is a ______ force
pulling force; it holds the walls of the object together
According to the law of Laplace, the tendency of an alveolus to collapse is ________ proportional to surface tension and ____________ proportional to alveolar radius
directly; indirectly
Wall stress is equal to
wall stress= (intraventricular pressure x radius) / ventricular thickness
When do type 2 pneumocytes begin producing surfactant?
22-26 weeks with peak production occurring at 35-36 weeks
The risk of ionizing radiation exposure to the anesthesia provider is:
a. directly proportional to the square of the distance of the source
b. directly proportional to the cubed radius of the distance from the source
c. inversely proportional to the square of the distance from the source
d. inversely proportional to the cubed radius of the distance from the source
c. inversely proportional to the square of the distance from the source
Ionizing radiation can remove _______ from atoms and this creates __________
electrons; free radicals
Risks of ionizing radiation exposure include
tissue injury
chromosomal damage
malignancy
Radiation exposure obeys the
inverse square law
it states that the amount of exposure is inversely proportional to the square of the distance of the source
Most radiation exposure in the hospital is the result of
scattered x-rays (not direct exposure)
What are the three ways to limit radiation exposure?
duration
distance
shielding
The minimum safe distance from the radiation source in the OR is
6 feet
The yearly maximum radiation exposure for adults is
5 rem
The yearly maximum exposure for the fetus of a pregnant works is
0.5 rem or 0.05 rem/month
In the non-pregnant person, the _____________ are most susceptible to injury from ionizing radiation
eye and thyroid
In the pregnant person, the __________ is most vulnerable to injury
the fetus
The _____- is how we quantify radiation exposure
roentgen (R)
How can you quantify the amount of exposure at two different locations?
intensity 1/ intensity 2= distance 2^2/distance 1^2
During a surgical procedure with fluoroscopy, the patient receives 40 mR at a distance of one foot from the radiation source. How much radiation will the anesthesia provider receive is she stands five feet from the radiation source?
1.6 mR
Other methods to minimize radiation exposure include
do not stand in the x-ray beam’s path
minimize exposure time
lead apron
lead glasses
lead shields
use a dosimeter (on the shirt collar near the thyroid gland)
List 6 locations where there’s an elevated risk for a CRNA to be exposed to ionizing radiation.
CT
nuclear medicine
anywhere where fluoroscopy is used
interventional radiology
cath lab
electrophysiology
The number of calories required to convert one gram of liquid to vapor without a temperature change in the liquid is called the:
a. latent heat of vaporization
b. boiling point
c. critical temperature
d. specific
a. latent heat of vaporization
____________- is the process where compound transitions from its liquid state to its gaseous state at a temperature below its boiling point
Evaporation
_______occurs when vapor pressure equals atmospheric pressure
Boiling
__________- is the amount of heat required to increase the temperature of 1 gram of a substance by 1 degree C
Specific heat
____________ is the pressure exerted by a vapor in equilibrium with its liquid or solid phase inside of a closed container
Vapor pressure
___________________ is the number of calories required to convert 1 gram of liquid to vapor without a temperature change in the liquid
Latent heat of vaporization
The Joule-Thompson effect explains why
an oxygen cylinder that is opened quickly feels cool to the touch
_____________ is the highest temperature where a gas can exist as a liquid
Critical temperature
Nitrous oxide and CO2 exists as liquids in an E cylinder because
their critical temperatures are above room temperature
_______________ is the minimum pressure required to convert a gas to a liquid at its critical temperature
Critical pressure
Evaporation can occur when vapor pressure is _________- atmospheric pressure
less than
Boiling occurs when vapor pressure _______________ atmospheric pressure
equals
Higher atmospheric pressure leads to
a higher boiling point
Vapor pressure is directly proportional to
temperature
Vaporization is the
process by which a liquid is converted to a gas. This requires energy (heat)
What is adiabatic process?
describes a process that occurs without gain or loss of energy (heat)
Joule-Thompson effect is an example
________________- is the highest temperature where a gas can exist as a liquid
Critical temperature
What is the critical temperature of nitrous oxide?
36.5 degrees C (liquid in the cylinder at room temp)
What is the critical temperature of CO2?
31 C (liquid in the cylinder at room temp
What is the critical temperature of oxygen?
-119 C
What is the critical temperature of air?
-140 C
What is the critical temperature of nitrogen?
-147 C
