i66 



BIOLOGY AND HUMAN LIFE 



THE AIR 



1. Composition of the atmosphere 



Nitrogen, 78 + % ; oxygen, 20 % ; 



2. Relation of air to life 



Oxidation of protoplasm 

 Yields energy 



Heat 



Motion 



Chemical action 



Electricity 



Light 



Nerve and mental energy 

 Comparison with other oxidation 



3. Respiration 



In one-celled organisms 

 Income 

 Outgo 



carbon dioxid, o.i — % 



Human breathing system 

 Structure 

 Lungs 



Connections with outside 

 Connections with body cells 

 Breathing habits and control 

 Mouth breathing versus nose 

 breathing 

 Removal of dust etc. 

 Temperature 

 Disagreeable appearance 

 Disagreeable sounds 

 Adenoids 



What they are 



How they influence breathing 



10 



Products of oxidation 

 Carbon dioxid (COg) 

 Water 

 Urea 

 (Other oxids) 



In many-celled organisms 

 Income 



Special openings 



Special tubes 

 Distribution 



Blood and lymph 



(Tracheae in insects) 

 Gathering of oxids 

 Outgo 



Process of breathing 

 Action of diaphragm 

 Action of rib muscles 

 Effects upon air currents 



Deep breathing 



Posture 



Related to breathing 

 Related to attitude 



Exercise 



Clothing 



