Physiology Review Flashcards
what is a good indicator of whether VA (alveolar ventilation) is enough for the animal’s needs?
PaCO2
what is vital capacity?
maximum volume the can be expelled from the lungs after a maximal inspiration
does carbon dioxide or oxygen diffuse more rapidly through tissues?
carbon dioxide
what happens to the affinity for oxygen when exercising?
affinity decreases because it becomes more acidic
releases oxygen more readily
where is carbon dioxide converted into bicarbonate?
within erythrocytes: carbonic anhydrase present
what are some causes of hypoxia?
decreased inspired PO2
alveolar hypoventilation
venous admixture/right-left shunt
ventilation/perfusion mismatch
diffusion impairment
how is carbon dioxide transported in the blood?
dissolved in plasma (minor)
bicarbonate
carbamino-Hb (minor)
what does pulmonary surfactant do?
reduces surface tension
allows surface tension to vary with alveolar radius
what is the oxygen-hemoglobin curve like at high PO2?
nearly flat: large changes in PO2 correspond with minor changes in saturation
large PO2 gradient at alveolus
what is the definition of a shunt?
blood flow but no oxygen
what is the definition of dead space?
oxygen but no blood flow
what is V/Q mismatch characterized by?
hypoxemia out of proportion to hypercapnia
what is the major stimulus for increasing ventilation?
PaCO2
