Term
Reaction for the carbonic anhydrase buffer system
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Definition
| H2O + CO2---> H2CO3---->HCO3 + H+ |
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Term
| Hypervenilaiton causes what to happen to pH? |
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Definition
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Term
| Hypovenilation is going to do what to pH? |
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Definition
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Term
| What is the function of the turbinates? |
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Definition
| causes air entering the nasal cavity to swirl, thereby giving it time to warm and humidify |
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Term
| why is there a watery saline layer near the cilia and mucus layer? |
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Definition
| it makes the mucus more viscous and therefore allows the cilia to move it |
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Term
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Definition
| Everything above the alveoli |
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Term
Alveoli have the natural tendency to collapse. Why is this the case?
what prevents this? |
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Definition
Because of the H bonding of water molecules
surfactant prevents this from happening |
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Term
| How does surfactant work? |
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Definition
| it decreases the surface tension by decreasing the density of water at the surface. This occurs because the hydrophobic tail of the surfactant is pulled upward out of the plane thus minimizing the vector. |
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Term
| About ____ percent of the alveoli are covered by blood vessels. |
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Definition
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Term
| Muscles used for inhalation |
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Definition
diaphragm
external intercostals
scalenes
sternocleidomastoids |
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Term
| muscles used for exhalation |
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Definition
diaphragm
internal intercostals
abdominal muscles |
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Term
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Definition
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Term
What does the alveolar pressure curve look like for inspiration and experioration.
start. middle. end. |
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Definition
Start at 0- your pressure is the same as atmospheric pressure
once you breath in, your volume gets bigger, pressure goes down and air begins to flow in. Midway through your inspiration, the pressure begins to build until it normalizes again with atmospheric pressure.
During experiation- pressure gets bigger, until about mid experiation when the pressure begins again to normalize with atm pressure.
start- 0
middle- 0
end-0 |
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Term
what does the intrapleural pressure curve look like for inspiration and experiation?
start. middle. end
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Definition
interpleural pressure starts negative. as the diaphragm contracts, and thoracic cavity pulls out, the interpleural pressure is going to decrease until the end of inspiration.
During experiation, the pressure goes back to starting position. |
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Term
| Why is intrapleural pressure always negative? |
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Definition
The pleura have a natural tendency to recoil
and
lymphatics drain fluid from the interpleural space creating a negative pressure |
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Term
| why would you want a negative pleural pressure in the lungs? |
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Definition
| causes the lungs to not collapse |
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Term
| what is the transpulmonary pressure? |
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Definition
| the difference in pressure between the alveolar and intrapleural pressure |
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Term
| when is the differnece between the alveolar and intrapleural pressure the greatest? |
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Definition
| at the end of inspiration |
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Term
| what is functional residual capacity? |
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Definition
| expiratory reserve volume + residual volume |
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Term
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Definition
| total lung volume - vital capacity |
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Term
what is total pulmonary ventilation?
Vt |
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Definition
| vent. rate x tidal volume |
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Term
| Alverolar ventilation (VA) |
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Definition
| Vent rate x (tidal volume - dead space volume) |
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Term
| what is physiological dead space caused by? |
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Definition
| due to alveoli not recieving circulation due to a blockage or something |
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Term
| what is another way to calculate VA using pressures? |
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Definition
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Term
| what is approximately the alveolar CO2 pressure? |
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Definition
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Term
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Definition
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Term
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Definition
increase respiration due to increase metabolism
ex. exercising |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| decrease respiration without change in metabolism |
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Term
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Definition
| increase in respiration without an increase in ventilation |
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Term
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Definition
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Term
alveolar CO2 is ______ to alveolar ventilation (VA)
what equation shows this?
how can you predict acidosis or alkolosis from VA? |
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Definition
inversely proportional
PACO2= 0.863 (VCO2/VA)
now since VCO2 is always about 200 ml, if VA changes you can see what happens to PACO2
normal VA= 4.2 L
if you double VA, then PACO2 decreases by half- lower CO2 pushes the curve to the left causing alkolosis...this is hyperventilation. (PaCO2 drops to 20 mmHg)
if you cut VA in half (for example during hypoventilation) then PACO2 would double. If PACO2 increases this is going to push the curve to the right, leading to acidosis...PACO2 in this instance would be 80 mm Hg |
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Term
| what would happen during hyperpnea to your PACO2 levels? |
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Definition
increase respiration, but your CO2 matches that--- so your line is a strait line according to the equation
PACO2= .863 (VCO2/VA) |
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Term
| Three types of resistance during breathing |
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Definition
CAT
C- Compliance (overcoming the elatic tendencies)
A- Airway resistance
T- Tissue resistance |
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Term
What is the formula for compliance?
what does compliance mean? what does it mean if something is compliant or not? |
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Definition
change in volume
_________________________
change in pressure
delta V/delta P
how easy is it for the lung to open...how much work needs to be done in order to open the lung |
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Term
At what point will compliance be the greatest?
and why? |
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Definition
compliance will be the greatest at the beginning of inspiration.
This is because you rapidly change the volume and get a much greater volume. Air moves in, but the pressure doesn't increase that rapidly. So, according to the formula (delta V/delta P) compliance would increase |
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Term
| Would an individual with firbrosis have be more or less compliant than normal. why or why not? |
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Definition
| less- Because of the fibrosis, it will take much more work to change the volume. with a small change in volume, the compliance is going to go down |
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Term
| what would the effect of emphysema be on someone's compliance? |
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Definition
| it is going to increase- you still get a big change in volume and the change in pressure is smaller because you have air that you can't get out. So pressure overall may be higher, but the change in pressure is smaller |
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Term
| What are two determining factors of Lung compliance? |
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Definition
Volume of the lung
- elastic forces
Surfactant |
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Term
| Some of the inspiratory work is due to tissue _________. |
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Definition
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Term
Air Flow is porportional to
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Definition
change in pressure
____________________________
resistance |
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Term
| Whata is Poiseuille's Law? |
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Definition
Resistance is determined by length of system, viscosity, and radius of tubes
R=8nl/pir^4 |
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Term
what is the most important determinant when determing respiratory resistance?
why? |
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Definition
radius of the tubes
r^4
if you double the radius your decrease the resistance 16 fold |
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Term
| How does mechanical forces affect the radius of respiratory tubes? |
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Definition
| pulls on the airways and opens them up |
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Term
| what is a physical aspect of the respiratory tubes that can decrease their radius? |
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Definition
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Term
| Mechanical, Physical, Neural factors, paracrine and endocrine factors all help determing the ______ of the respiratory tubes. |
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Definition
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Term
sympathetic stimulation leads to bronchi ______.
parasympathetic stimulation leads to bronchi _______. |
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Definition
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Term
is a paracrine factor going to have a local or global response?
endocrine? |
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Definition
paracrine- local
endocrine- more global |
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Term
| Does turbulent or Laminar flow provide more resistance? |
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Definition
| Turbulent. Lamanar flow is less resistant |
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Term
| What does the Reynold's number measure? |
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Definition
| airflow. higher the number the more turbulent. lower number means lamanar flow |
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Term
| what is the equation for Reynold's number? |
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Definition
R= vpd/n
(velosity)(density)(diameter)
--------------------------------------------
(viscosity) |
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Term
If you increase the diameter with there be more or less turbulent airflow?
where would you find the least resistance of airflow? |
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Definition
more
alveoli where the diameter is smaller |
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Term
| When airflow is turblent resistance (increases or decreases) and flow (increases or decreases)? |
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Definition
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Term
| Normally the largest resistance to airflow is in the largest airways, but during COPD the largest resistance is in ___________? |
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Definition
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Term
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Definition
| perfusion- delivering blood to capillaries around the alveoli |
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Term
what is the V/Q ratio?
what is it normallY? |
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Definition
amount of ventilation/perfusion
V/Q= 1 |
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Term
what happens to V/Q when there is physiological dead space?
(what is physiological dead space?) |
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Definition
physiological dead space is when blood is not being perfeused to an area. ex. alveoli
V/Q >1 |
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Term
| what happens to V/Q when ventilation is poor? |
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Definition
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Term
what happens to a lung when there is a dead space to one of the lungs?
explain P O2, P CO2 ect. (explain for both lungs) |
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Definition
| on the side with the perfusion the PO2 levels are going to be very high, higher than normal because there will be no CO2 being exchanged and there is only a minimal amount of CO2 in the air- so the alveolor air becomes equal to that of the air which has a high concentration of O2. Meanwhile, the other lung is going to have increased perfusion causing a higher Q leading to increased PCO2 and decreased PO2 |
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Term
| Say there was a high V/Q caused by physiological dead space in some of the pulmonary capilaries. What is the compensatory mechanism for this? |
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Definition
| if there is a high V/Q becuase of low perfusion, then you would have high O2 and low CO2 and high pH. This causes bronchioconstriction which lowers V and thus lowers V/Q. because perfusion is low, Type II pneumocytes stop producing as much surfactant which causes alveoli to condense and get smaller because they are less compliant and have a smaller amount of ventilation. |
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Term
what if one of the lungs was shunted producing a low V/Q.
what is the compensatory mechanism for this? (hypoxia) |
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Definition
if V/Q is low (less than 1) this is most often caused by low ventilation. O2 is low and CO2 is high. this causes the the other lung increases perfusion
To compensate; the lung that is hypoxic causes vasoconstriction to that area; this is called hypoxic vasoconstriction.
NOTE!! THIS IS DIFFERENT FROM WHAT WOULD NORMALLY HAPPEN IN TISSUES. IN TISSUES, THE ARTERIOLES WOULD NORMALLY VASODIALATE. |
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Term
Describe where you would seen zone
1-4 breathing.
and describe which each of the zones are |
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Definition
zone 1- disease state. This occures when alveolar pressure exceeds capillary pressure almost all the time, so the capillary is almost always closed and V/Q is high.
zone 2- intermittent flow where sometimes the capillary pressure is higher and other times the alveolar pressure is higher. V/Q is greater than 1. this is going to happen at the top of the lung.
zone 3- capillary pressure is greater than the alveolar pressure some V/Q is going to be less than 1. This is going to be at bottome part of the lung
zone 4- The pressure is so great that the capillary is extended. V/Q is smallest out of each of the zones. This is at the very base of the lung. |
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Term
| At what part of the lung is V/Q matched the best? |
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Definition
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Term
| where is pressure the highest in the lung and why? |
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Definition
| the pressure at the bottom of the lung is higher than the pressure at the top part of the lung because of hydrostatic pressure. |
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