Respiratory5 Flashcards
V/Q mismatch CO2 transport High Altitudes Exercise
Ideally, ventilation/perfusion (V/Q) = ?
1
ventilation matched to perfusion allows for adequate gas exchange
What is the V/Q at the apex of the lung?
3 (wasted ventilation)
What is the V/Q at the base of the lung?
0.6 (wasted perfusion)
T/F - Both ventilation and perfusion are greater at the base of the lung than at the apex of the lung.
True
What happens to the apical capillaries during excercise (INcreased CO?
They vasodilate -> V/Q ratio approaches 1
What type of organisms thrive in the apex of the lung?
Organisms that like High O2 concentration
- i.e., TB
What are the 3 forms Carbon Dioxide is transported from tissues to the lungs?
- Bicarbonate (90%)
- Carbaminohemoglobin or HbCO2 (5%)
- CO2 bound to hemoglobin at N-terminus of globin (not heme). CO2 binding favors T (taut) form (O2 unloaded)
- Dissolved CO2 (5%)
What is the Haldane Effect?
In lungs, oxygenation of Hb promotes dissociation of H+ from Hb. This shifts equilibrium toward CO2 formation; therefore, CO2 is released from RBCs
What is the Bohr effect?
In peripheral tissue, INcrease H+ from tissue metabolism shifts curve to the right, unloading O2
What is the acute response to high altitude?
INcreased ventilation
DEcreased PO2 & PCO2
What are the effects of the Increased ventilatin in response to chronic exposure to high altitude? (4)
- INcreased EPO -> INcreased hct & Hb
- Chronic hypoxia
- INcreased 2,3-BPG
- Binds to Hb so that Hb releases more O2
- Cellular changes
- INcreased Mitochondria
- INcreased renal excretion of bicarbonate
- Compensates for respiratory alkalosis
What is the result of chronic hypoxic pulmonary vasoconstriction?
Right Ventricular Hypertrophy (RVH)
What happens to CO2 production during exercise?
INcreased
What happens to the V/Q ratio during exercise?
From Apex to Base it becomes more uniform
What happens to pulmonary blood flow during exercise?
INcreased d/t INcreased Cardiac Output
