Oxygen Concentration and Exercise

At rest, what is the oxygen concentration in arterial blood?

• 150 mL O₂/L

• 180 mL O₂/L

• 190 mL O₂/L

• 200 mL O₂/L

At rest, what is the oxygen concentration in venous blood?

• 160 mL O₂/L

• 170 mL O₂/L

• 180 mL O₂/L

• 190 mL O₂/L

Why does our heart rate increase during exercise?

• To slow breathing

• To lower body temperature

• To reduce muscle strain

• To pump more oxygenated blood to the muscles

Why does the amount of oxygen in arterial blood remain stable during exercise?

• Arteries store oxygen

• Veins return oxygen to the arteries

• The heart stops using oxygen

• Arterial blood is constantly replenished with oxygen from the lungs

What type of blood vessel carries oxygenated blood away from the heart?

• Veins

• Arteries

• Both arteries and veins

• Neither arteries or veins

Describe the relationship between exercise and the concentration of oxygen in venous blood.

• Oxygen concentration in venous blood stays the same

• Oxygen concentration in venous blood increases

• Muscles stop using oxygen

• Oxygen concentration in venous blood decreases as exercise intensity increases

Why does breathing rate increase during exercise?

• To slow heart rate

• To prevent overheating

• To remove carbon dioxide

• To supply more oxygen to the bloodstream

What is the normal function of carbon dioxide (CO₂) in the blood during gas exchange?

• To carry oxygen to muscles

• To increase oxygen concentration

• To lower blood pressure

• To be expelled as a waste product from the body

Based on your knowledge of biology, predict how CO₂ concentration in venous blood changes during exercise.

• CO₂ decreases in venous blood

• CO₂ stays the same in venous blood

• CO₂ is completely removed

• CO₂ concentration increases in venous blood

Explain how the respiratory and circulatory systems work together to maintain stable arterial oxygen levels during exercise.

• Heart pumps faster to increase CO₂

• Breathing rate slows

• Oxygen levels drop during exercise

• Increased heart and breathing rates deliver more oxygen to the bloodstream