Breathing and Exchange of Gases (2022) - Quiz 2

Which of the following statements about the mechanism of ventilation / breathing is false?

• As the diaphragm relaxes, air is expelled from the respiratory system

• During inspiration the lungs act as suction pump

• Inspiration is a passive and expiration is an active process

• For quiet breathing external intercostal muscles and diaphragm play an important role

Inspiration occurs when there is a negative pressure in the lungs with respect to atmospheric pressure. This negative pressure is achieved when –

• Intrapulmonary pressure is less than the atmospheric pressure

• Intra pulmonary pressure is greater than the atmospheric pressure

• Intrapulmonary pressure is equal to the atmospheric pressure

• Intrapleural pressure becomes more than the intraalveolar pressure

Exchange of gases –

• Occurs between the alveoli and pulmonary blood capillary

• Occurs between blood and tissues

• By diffusion

• All

Which of the following factors affect the diffusion of gases?

• Partial pressure of diffusing gases

• Solubility of gases

• The thickness of diffusion membrane

• All

Which of the following statements about the partial pressure of CO₂ is true?

• It is higher in alveoli than in pulmonary artery

• It is higher in the systemic arteries than in tissues

• It is higher in systemic veins than in systemic arteries

• It is higher in the pulmonary veins than in pulmonary arteries

The partial pressure of CO₂ in the venous blood is –

• Greater than in the tissue spaces

• Lesser than in the tissue spaces

• Lesser than in the arterial blood

• Less than in alveoli

The barrier between the air in alveolus and blood in pulmonary capillary consists of 3 layers and its total thickness

• 1 mm

• more than 1 mm

• much less than 1 mm

• 2 mm

Expiratory capacity is equal to –

• TV + ERV

• ERV + IRV

• ERV + RV

• ERV + RV

A spirometer cannot be used to measure –

• IC

• RV

• ERV

• IRV

Tidal Volume and Expiratory Reserve Volume of an athlete is 500 mL and 1000 mL, respectively. What will be his Expiratory Capacity if the Residual Volume is 1200 mL ?

• 1500 mL

• 1700 mL

• 2200 mL

• 2700 mL