exercise

Question 1

Respiratory Quotient/Respiratory Exchange Ratio

Answer 1

CO2 production/oxygen consumption - usually = 1

Question 2

Muscle response to exercise:

Answer 2

Muscle response to exercise: stored energy (ATP, PCr) used to generate muscular contraction; inorganic phosphates, ADP and creatine drive oxidative phosphorylation while Krebs/glycolysis increases; oxygen consumption at muscle increases, and initially CO2 production rises slowly (as buffered), but then rises to match O2

Question 3

circulatory response to exercise

Answer 3

Circulatory response to exercise: CO increases linearly with intensity until plateaus as maximum reached, alongside HR and oxygen consumption - exercise limited by cardiac output; when HR too fast, filling time in diastole reduced, which reduces SV after a peak

Question 4

lung response to exercise

Answer 4

Lung response to exercise: VT increases with ventilation up to a peak where plateaus, and breathing frequency increases - will breathe at half vital capacity in exercise (increase further not as efficient); VQ matching at rest not ideal, but in exercise increases

Question 5

Fick equation:

Answer 5

CO = Oxygen Consumption / (a - v) O2 content

Question 6

bohr effect

Answer 6

Bohr effect: as pH increases, Bohr shift of ODC to right so at given PO2 Hb has less affinity to oxygen so offload more to acidotic muscles

Question 7

acidosis

Answer 7

Acidosis: lactate converted to protons, and is buffered by bicarbonate to increase CO2, increased ventilation allows pH to remain relatively stable; when [H+] exceeds HCO3- cannot buffer and begin hyperventilation