Respiratory Physiology 2 Flashcards
What is Dalton’s law?
The total pressure of a gas mixture is equal to the sum of the pressures that each gas in the mixture would exert independently
The pressure that a particular gas in a mixture exerts independently
partial pressure
What percent of oxygen in the atmosphere
21%
With increasing altitude, total and partial pressure of gases _______
decrease
When does gas dissolved in fluid reach maximum value
when a liquid and gas (like blood and alveolar air) are at equilibrium
What does the value of equilibrium between a gas and a liquid depend on according to Henry’s law?
solubility of gas in the fluid, temperature, and partial pressure of the gas
What does the oxygen electrode measure?
dissolved oxygen in water or plasma, not o2 bound to hemoglobin
At a normal PO2 what is the oxyhemoglobin saturation
97%
What device measures oxyhemoglobin saturation
pulse oximeter
T/F supplemental oxygen improves athletic performance
False
Where is arterial blood gas test generally performed?
radial artery
Why are values of arterial blood clinically significant but not venous blood?
because they are relatively constant and reflect lung function while venous is more variable
Gas exchange for CO2 moves from _____ to _____
tissues to blood
Breathing 100% oxygen below 2.5 atmospheres of pressure can lead to
oxygen toxicity
“rapture of the deep”
nitrogen narcosis
What happens in decompression sickness
if diver surfaces too quickly nitrogen gas bubbles form and blood small vessels
How to treat decompression sickness and what law explains the treatment
hyperbaric oxygen therapy, Boyles law
What else can HBOT treat?
gas gangrene and carbon monoxide poisoning
Where is the respiratory control center?
medulla oblongata
What controls automatic breathing?
rhymicity center, central and peripheral chemoreceptors
Where are central chemoreceptors located
medulla oblongata
Where are peripheral chemoreceptors located?Te
aortic bodies and carotid bodies
What chemoreceptors send info to medulla via the vagus nerve and what sends info via the glossopharangeal nerve?
aortic, carotid
Brainstem dysfunction that leads to fatal apnea when sleeping
ondine’s curse
Two ways to get ondine’s curse
trauma to brainstem or congenital central hypoventilation syndrom
How to treat a defective gene in the retrotrapezoid nucleus of the medulla
ventilation and tracheostomy
Hypoventilation leads to
rise in PCO2 and fall in pH (acidic
Why does blood oxygen content decrease more slowly than CO2
becase of reservoir in hemoglobin
What is more immediately affected by changes in ventilation
PCO2 and pH
Other names for hypoventilation and hyperventilation
hypercapnia and hypocapnia
What stimulates a newborn to take its first breath? And what do they primarily use to breath?
buildup of CO2 and fall in pH, nose
Hyperventilation in swimmers can lead to
shallow water blackout
What process occurs that could lead to death in swimmers from hyperventilation?
hypervenilation- blows off CO2–>respiratory alkalosis–>vigorous swimming reduces oxygen levels (weak stim for breathing)–> insufficient O2 for aerobic metabolism–> ATP levels drop in the brain–> unconsciousness
aortic and carotid bodies are stimulated by _____ while the medulla chemoreceptors are stimulated by _____
H+, PCO2
Immediate increase in ventilation is produced by _____ but ____ is ultimately responsible for most of the increased ventilation in response to arterial PCO2 increases
peripheral chemoreceptors, chemoreceptors in the medulla
How does hypocapnia affect calcium
lowers plasma calcium—> tetany
How does blood PO2 affect breathing
indirectly by influencing the chemorecptor sensitivity changes to PCO2
When oxygen can significantly stimulate ventilation
hypoxic drive
The direct effect of PO2 on carotid bodies is carried out by
glomus cells in carotid bodies
How are people with emphysema stimulated to breath and why?
hypoxic drive, because chemoreceptor response becomes sensitized to chronically high CO2
Why is the way people with emphysema stimulated to breath medically important?
If you give them an oxygen mask they may stop breathing, so you need to manually ventilate for them
Another name for SIDS
crib death
Hypothesized cause of SIDS
failure of central or peripheral chemorecptors to detect rise in CO2
dangers of obstructive sleep apnea
pulmonary hypertension and right ventricle hypertrophy
Treatment of sleep apnea
continuous positive airway pressure
