Lecture 22 - Volume, Capacity, & Gas Exchange Flashcards
what is the inspiratory reserve volume
max capacity of air the lungs can take in
what is tidal volume
air breathed at rest
what is the expiratory reserve volume
air that leaves the body during forced expiration
what is the residual volume
air still left in the lungs to maintain surface tension
what is the inspiratory capacity
the air the lungs can intake during inspiration
(inspiratory reserve + tidal volume)
what is the functional residual capacity
air left after passive exhalation
expiratory reserve + residual volume
T/F: the residual capacity is the most clinically relevant
TRUE
what is the vital capacity
all air inspired and expired (not including the air that stays in the lung to maintain surface area)
what happens if FRC is increased?
increased air trapped cannot exchange with fresh gas
increased FRC leads to ____ lung elasticity
decreased (elastic recoil, emptying, etc.)
what is increased with increased FRC
compliance
what are examples of diseases that result in increased FRC
asthma, mucous plugging, emphysema
what happens if FRC is decreased?
reduced air/gas reserve
what are the 5 reasons for decreased FRC?
- increased thoracic pressure (pregnancy, GDV)
- thoracic pain (broken ribs)
- pneumothorax/pneumomediastinum
- anesthesia (relaxation of mm.)
- absorption atelectasis
respiratory rate
tidal volumes per minute
characterized by rate and effort
oxygenation
refers to oxygen level in blood
- emia
ventilation
refers to carbon dioxide levels in blood
- capnia
Vmin
total amount of fresh air that enters the conducting airways
VT x respiratory rate
alveolar ventilation
total volume of new air entering alveoli per minute (“effective”)
bulk flow
movement of gas from high-pressure to low-pressure systems
diffusion
movement of air down the concentration gradient
take a normal breath in, then exhale as forcefully as you can. is there any air left in your lungs? if yes, what is it called?
Yes - residual volume
which of the following is true regarding FRC?
a. increased FRC allows for more efficient gas exchange
b. increased FRC is common in pregnant animals
c. increased FRC means less air “gets out”
d. elite athletes often have increased FRC
c. increased FRC means less air “gets out”
if gas pressure increases, diffusion ____
increases
Oxygen is highest in the
alveoli
carbon dioxide is highest in
tissues
what is atmospheric pressure
760 mmHg
how much of atmospheric pressure is oxygen
21%
how much of the atmospheric pressure is carbon dioxide
0.3 mmHg
what are the pressures of arterial and venous oxygen
a = 100 mmHg
v = 40 mmHg
what are the pressures of arterial and venous carbon dioxide
a = 40 mmHg
v = 45 mmHg
what is Henry’s Law
solubility of a gas in liquid is directly proportional to its partial pressure above the liquid
what 3 things help maintain the oxygen gradient
- large pressure difference between alveoli and capillaries
- rate of alveolar diffusion
- oxygen that binds with hemoglobin
what maintains the carbon dioxide gradient
- continuous production
- eliminated by ventilation
Ventilation (V)
movement of air to and from alveoli
Perfusion (Q)
movement of blood to and from the barrier
what is the nitrogen skeleton
refers to nitrogen in air that prevents alveoli from collapsing
hypoventilation results in
hypercapnia
hyperventilation results in
hypocapnia
