More lecture 8 qs Flashcards
From cassidy's practice qs + ppt
What function does cartilage have in the conducting zone?
Prevent collapse
Where is the majority of pulmonary circulation (gas exchange) occurring?
Alveolar surface area
How many layers of type 1 alveolar cells make up the alveolar sacs?
1
What happens to our number of alveoli, alveolar surface area, and skin surface area as we age?
Increases
Which of the following are respiratory muscles?:
Scalenes
Sternocleidomastoids
Diaphragm
Intercostals
All
What law states that barometric pressure is equal to the sum of the partial pressures of the individual gasses?
Dalton’s law
Which law states that the pressure exerted by a gas is inversely proportional to the volume it occupies?
Boyle’s law
What are the two main functions of pressure within the lung?
Prevent airway collapse
Prevent lung collapse
Transmural pressure/ Transpulmonary pressure is the difference of what?
Alveolar pressure - pleural pressure
What does the diaphragm do during expiration?
Moves up
What is the maximum lung capacity?
4200-5700mL
What is described as air exchanged during a single breath?
Tidal volume
How would FEV1 change in someone with COPD compared to a normal baseline?
Lower
FEv1 is usually what percent of vital capacity?
80%
What does FEv1 indicate?
Maximal airflow rate
What’s the difference between RV and FRC? (functional residual capacity)
FRC is volume of air remaining after normal expiration (ERV + RV), RV is ) minimum air remaining after maximum expiration (1200mL)
Extra volume that can be expired after normal expiration (1000mL) is called what?
ERV
What is IRV + TV?
Inspiratory capacity (IC) ; maximum amount of air that can be inspired after normal expiration
Maximum amount of air that can be expired after maximal inspiration (IRV + TV + ERV) is called what?
Vital capacity (VC)
The maximum volume that lungs can hold (vital capacity + residual volume = 5700mL) is called what?
Total lung capacity (TC)
Tidal volume x respiratory rate = what?
Pulmonary ventilation
Of the 500mL inspired, how much of that remains in the airways as dead space?
150mL
During expiration, some of the air remains in the airways. Why?
So airways don’t collapse
What is equal to the (tidal volume minus the dead space volume) x the respiratory rate?
Alveolar ventilation
What causes a fall in PaCO2?
Hyperventilation
List the 3 basic components of the elastic properties of the lungs
Elastic recoil
Distensibility
Stiffness
What 3 things effect lung compliance?
Lung size
Lung volume
Surface tension inside the alveoli
COPD is an example of what kind of lung compliance?
Low
What type of COPD is caused by alveolar destruction from chronic exposure to cigarette smoke and other irritants?
Emphysema
What type of COPD is from long term inflammation of lower airways from smoking, pollution, and allergens and causes prolonged thickening of airways, mucus overproduction, and infrequent infections?
Chronic bronchitis
What are the 3 jobs of pulmonary surfactant?
1) Intersperses water molecules and lower alveolar surface tension to increase pulmonary compliance
2) Reduce recoil
3) Stabilize alveoli
The primary determinant of resistance is airway _________.
radius
What is the major site of airway resistance for decreasing airflow?
Bronchi
What two things stimulate B2 adrenergic receptors to cause dilation of the airway, altering its patency?
Epinephrine
Isopropanol
Higher altitude leads to ______ gas exchange of O2 due to lower amount of pressure in the atmosphere.
lower
What law states that the rate of gas diffusion is inversely related to membrane thickness and directly proportional to surface area?
Fick’s law
What does CO2 mostly bind to?
Bicarbonate
(30% bound to Hgb, 60% as bicarb, 10% dissolved)
When are smaller airways dilated? What does this mean?
When thorax is expanded; this means resistance during inspiration is lower than expiration
What flow is the major determinant in transferring oxygen from the alveoli to the blood?
Pulmonary capillary blood flow
What is the main factor for Hgb saturation?
Partial gradient
The measure of extent to which Hgb is combined with O2 is called what?
Hgb saturation
The statement “if the concentration of one substance in a reversible action is decreased, the reaction is driven in the opposite direction” is a part of what?
Law of mass action
If surrounding blood is low in O2, oxyhemoglobin will dissociate into what?
Hemoglobin and oxygen
If surrounding blood is high in O2 (like in pulmonary capillaries), O2 will combine with hemoglobin into what?
oxyhemoglobin
The O2-Hgb dissociation (or saturation) curve is the relationship between what?
Partial gradient of O2 and Hgb saturation
What does the steep portion of the O2-Hgb dissociation curve represent?
O2 unloaded at systemic capillaries
What does the plateau portion of the O2-Hgb dissociation curve represent?
O2 loaded onto Hgb at pulmonary capillaries
A respiratory malfunction or high altitude/suffocating environment causes what?
Hypoxic hypoxia
What poison causes histotoxic hypoxia?
Cyanide
Define hypercapnia
Too much CO2
List 4 factors that can affect Hgb saturation and cause less oxygen to be bound to it
CO2
Acidity
Temperature
2,3-bisphosphoglycerate (BPG)
What production increases when Hgb is chronically undersaturated>
BPG (2,3-bisphosphoglycerate)
