20 Demo Exercise and Caridiorespiratory System

Question 1

Define respiratory quotient and state respiratory quotient for glucose, lipid and protein metabolism

Answer 1

It is the ratio between the CO2 produced and the O2 consumed

Glucose: 1
Protein: 0.8
Lipid: 0.7

Question 2

What is the oxygen requirement when seated at rest

Answer 2

3.5ml/min/kg of oxygen

Question 3

What is the circulation’s response to incremental exercise

Answer 3

Cardiac output increases until plateau

• Heart rate increases
• Stroke volume increases initially until when the HR is too high to produce effective pump, it decreases

Question 4

What is the equation of oxygen consumption (VO2) and use the equation to describe the effect of exercise

Answer 4

VO2 = cardiac output x (a-v) O2 content

During exercise:

• cardiac output increase 4-7 fold
• oxygen consumption increases 10-15 fold
• mixed venous saturations at rest: 75% but during exercise it can go down to 15%