IB Ventilation & Gas Exchange

Which term describes the physical movements in the thorax which bring fresh air to the alveoli and remove stale air?

• gas exchange

• respiration

• ventilation

• circulation

Which of the following is/are processes of all living organisms?

• ventilation

• homeostasis

• metabolism

• respiration

Which of the following is/are true for inhalation?

• internal intercostal muscles contract

• ribcage moves up and out

• volume in the thorax decreases

• air enters when pressure in the thorax is below atmospheric pressure

Which of the following is/are true for exhalation?

• internal intercostal muscles contract

• diaphragm muscle is dome-shaped

• diaphragm muscle relaxes

• the pressure in the thorax increases above atmospheric pressure

Which of the following is/are correct adaptations of alveoli for fast gas exchange?

• thin cell wall gives a short diffusion distance

• moist inner surface to dissolve O₂ and CO₂ for diffusion in solution

• gas exchange maintains concentration gradients between alveoli and blood

• close to blood capillaries gives a short diffusion distance

Which one of the following maintains a low concentration of oxygen in blood capillaries, to maintain a concentration gradient?

• respiration

• ventilation

• circulation

• evaporation

Which of the following is/are true of Type 1 pneumocytes?

• They are thin and permeable cells

• They secrete a chemical called surfactant

• There is a single layer of these cells in alveoli walls

• They help to dissolve gases

Which of the following is/are true of Type 2 pneumocytes?

• The surfactant that they secrete increases surface tension

• They prevent the sides of alveoli from sticking together

• They help gases to dissolve

• They are found on the inner surface of alveoli

Which of the following is/are true of the lung disease emphysema?

• It is caused by bacteria

• Damaged cells release trypsin enzyme

• Elastic fibres in alveoli membranes are digested

• Alveoli walls break down

Which of the following is/are true of the lung disease emphysema?

• The diffusion distance between alveoli and blood increases

• Alveoli become larger

• Cilia are damaged so less bacteria can enter the lungs

• Alveoli cannot recoil as easily