Resp 2 Flashcards
(29 cards)
What factors influence gas exchange in the lungs?
Surface area, membrane thickness, pressure differences (Dalton’s Law), molecular weight, and gas solubility (Henry’s Law).
What does the VA/Q ratio represent?
The balance between alveolar ventilation (VA) and perfusion (Q) in the lungs.
What does Dalton’s Law state?
The total pressure of a gas mixture is the sum of the partial pressures of its components.
Why is the partial pressure of oxygen lower at high altitudes?
Because the atmospheric pressure is lower, reducing oxygen’s partial pressure.
What physiological adaptations help people at high altitude?
Increased 2,3-DPG and polycythemia.
What does Henry’s Law describe?
The amount of gas dissolved in a liquid is proportional to its partial pressure.
Why does CO₂ diffuse more efficiently than O₂?
Because CO₂ is 22 times more soluble in plasma.
What is the Bohr effect?
CO₂ and H⁺ reduce hemoglobin’s affinity for O₂, enhancing oxygen release in tissues.
How does myoglobin differ from hemoglobin?
Myoglobin is monomeric with higher O₂ affinity; hemoglobin is tetrameric and allosteric.
What is the chloride shift?
Bicarbonate ions are exchanged for Cl⁻ in red blood cells to maintain charge balance.
How is CO₂ transported in the blood?
7% in plasma, 23% bound to hemoglobin, 70% as bicarbonate.
What promotes oxygen release from hemoglobin during exercise?
Low pH, high temperature, and increased 2,3-DPG.
What causes ketoacidosis in diabetes?
Fat breakdown leads to ketone production, which are acidic.
How does the body compensate for ketoacidosis?
Hyperventilation to exhale CO₂ and kidneys excrete H⁺, reabsorb HCO₃⁻.
What causes lactic acidosis during exercise?
Anaerobic metabolism of glucose produces lactic acid.
How does the body respond to lactic acidosis?
Hyperventilation and renal excretion of H⁺, reabsorption of HCO₃⁻.
What can cause metabolic alkalosis?
Vomiting, diarrhoea, antacid ingestion, volume depletion.
How does the body compensate for metabolic alkalosis?
Hypoventilation, kidneys reabsorb H⁺ and excrete HCO₃⁻.
How does hyperventilation cause respiratory alkalosis?
Excess CO₂ is lost, increasing blood pH.
What are the body’s responses to respiratory alkalosis?
Hypoventilation, kidneys excrete HCO₃⁻ and reabsorb H⁺.
How does hypoventilation cause respiratory acidosis?
CO₂ accumulates in blood, decreasing pH.
How does the body compensate for respiratory acidosis?
Hyperventilation and renal H⁺ excretion with HCO₃⁻ reabsorption.
What is spirometry used for?
Measuring lung volume and air flow.
What are the key volumes measured in spirometry?
Tidal Volume (TV), Residual Volume (RV), Total Lung Capacity (TLC), Vital Capacity (VC)/FVC.
