Physiology Flashcards
Air that can still be breathed in after normal inspiration
Inspiratory reserve volume
Air that moves into lung with each quiet inspiration
Tidal volume
Volume breathed in during tidal volume
500 ml
Air that can still be breathed out after normal expiration
Expiratory Reserve Volume
Air that can still be exhaled after normal exhalation
Inspiratory Capacity
Lung volumes that make up IC
IRV + TV
Volume of gas in lungs after normal expiration
Functional Reserve Capacity
Lung volumes that make up FRC
ERV and RV
Maximum amount of gas that can be expired after a maximal inspiration
Vital Capacity
Lung volumes that make up VC
IRV, TV, ERV
Volume of gas present in lungs after a maximal expiration
Tidal Volume
Anatomic dead space of conducting airways plus alveolar dead space
Physiologic dead space
Formula for Physiologic dead space
V(D) = V(T) x PaCO2 - P(E)CO2/PaCO2
In healthy lungs what does physiologic dead space approximate
Anatomical dead space
When part of the respiratory zone becomes unable to perform gas exchange
Pathologic dead space
Formula for Ventilation
V(A) = V(E) - V(D)
Total volume of gas enter lungs per minute
Minute ventilation: V(E)
Formula for minute ventilation
V(E) = V(T) x RR
Volume of gas per unit time that reaches alveoli
Alveolar ventilation: V(A)
Formula for alveolar ventilation
V(A) = [V(T) - V(D)] x RR
Normal V(T) in healthy individuals
500 ml/breath
Normal physiologic dead space in healthy individuals
150 ml/breath
Tendency for lungs to collapse inward and chest wall to spring forward
Elastic recoil
When is pulmonary vascular resistance at minimum
at FRC
What is the airway and alveolar pressures at FRC
Zero
High compliance of lungs is seen in which conditions
Emphysema and aging
Low compliance of lungs is seen in which conditions
Pulmonary fibrosis, pneumonia, NRDS, pulmonary edema
At what lung capacity are inward pull of lungs balanced by outward pull of chest wall
FRC
At what lung capacity is respiratory system pressure atmospheric
FRC
Which form of hemoglobin has low affinity for O2
Deoxygenated form
What are the different conformations of hemoglobin
Tense and relaxed
Conformation of deoxygenated hemoglobin
Tense
Which form of hemoglobin has high affinity for O2
Relaxed
Cause for increased affinity for O2 in HbF
Decreased affinity for 2,3 BPG
Type of air flow found in median bronchi
Turbulent flow
Type of air flow found in terminal bronchioles
Slow laminar flow
Airways with highest airway resistance
Medium bronchi
Airways with lowest airway resistance
Terminal bronchioles
Presents with chocolate-colored blood and cyanosis
methemoglobinemia
Treatment for methemoglobinemia
Methylene blue and vitamin C
Form of iron in hemoglobin that bind O2
Fe2+ (reduced state)
Oxidized form of Hb that does not bind O2 as readily but has high affinity for cyanide
Methemoglobin
Treatment for cyanide poisoning
Nitrites followed by hydroxocobalamin and thiosulfate
When would you induce methemoglobinemia
In cyanide poisoning (excreted renally)
Form of Hb bound to CO in place of O2
Carboxyhemoglobin
Result of carboxyhemoglobin on O2-dissociation curve
Left shifts curve causing decreased O2 unloading to tissues
Treatment in patient presenting with headaches, dizziness and cherry-red skin after smoke exposure
100% O2 and hyperbaric chamber
Percentage of carboxyhemoglobin in healthy individuals
3%
Percentage of carboxyhemoglobin in smokers
10-15%
Percentage of carboxyhemoglobin in CO poisoning
Greater than 15%
Type of Hb in patient exposed to nitrites or benzocaine
Methemoglobin
Form of iron with decreased O2 affinity and increased cyanide affinity
Fe3+