Understanding Human Respiration System

Which structure in the human respiratory system is primarily responsible for the exchange of gases?

• Trachea

• Alveoli

• Bronchi

• Diaphragm

What is the main function of the diaphragm during inhalation?

• To contract and push air out of the lungs

• To relax and allow the lungs to expand

• To contract and increase the volume of the thoracic cavity

• To filter dust particles from the air

Which adaptation of the alveoli increases the efficiency of gas exchange?

• Thick walls

• Large surface area

• Low blood supply

• Dry surface

How is oxygen transported in the blood?

• Dissolved in plasma only

• Bound to haemoglobin in red blood cells

• Attached to platelets

• Carried by white blood cells

What happens to the rate of respiration during vigorous exercise?

• It decreases

• It remains unchanged

• It increases

• It stops

Which gas diffuses from the alveoli into the blood during gas exchange?

• Carbon dioxide

• Nitrogen

• Oxygen

• Argon

What is the role of surfactant in the alveoli?

• To increase surface tension

• To prevent alveolar collapse

• To absorb oxygen

• To transport carbon dioxide

Which of the following best describes the walls of alveoli?

• Thick and muscular

• Thin and moist

• Dry and rigid

• Covered in cartilage

During exhalation, what does the diaphragm do?

• Contracts and moves downwards

• Relaxes and moves upwards

• Contracts and moves upwards

• Relaxes and moves downwards

Which blood vessel carries oxygenated blood from the lungs to the heart?

• Pulmonary artery

• Pulmonary vein

• Aorta

• Vena cava