1 (a) Energy is obtained from food by a process called respiration (A). (b) The intake of oxygen and output of carbon dioxide at a respiratory surface is called gaseous exchange (B). (c) The process of renewing air in the lungs is called ventilation (C). (d) The processes B and C are included in the term ‘breathing’.
4 Using the words 'cilia' and 'mucus', describe, very briefly, how the body gets rid of dust which enters the lungs.
The lining of the air passages produces mucus which traps dust particles. Cilia in the lining flick to and fro to carry the mucus up and out of the passages.
6 In what two ways will the composition of blood coming from the pulmonary artery differ from that going to the pulmonary vein?
Blood in the pulmonary artery will contain less oxygen and more carbon dioxide than blood in the pulmonary vein.
10 State four characteristics of an efficient respiratory surface.
Four characteristics of an efficient respiratory surface are: thin epithelium, large surface area, abundant capillaries, ventilation mechanism.
11 What process causes oxygen to pass from the alveoli into the lung capillaries?
DIFUSSION