14 



Respiratory and Buoyancy Systems 



A. Introduction 



1. External and internal respiration 



2. Basic structural relationships involved in external respiration 



a. Cellular relationships 



b. Sites or areas where external respiration is accomplished 



c. Main types of organs used for respiration 



B. Development of bronchial or gill respiratory organs 



1. Development of gills in fishes 



a. Development of gills in Squalus acanthias 



b. Gills of teleost fishes 



c. External gills 



2. Development of gills in Amphibia 



a. General features 



b. Development of gills in Necturus niaculosus 



c. Development of gills in the larva of the frog, Rana pipiens 



1) Development of external gills 



2) Formation of the operculum 



3) Internal gills 



4) Resorption and obliteration of gills 



C. Development of lungs and buoyancy structures 



1. General relationship between lungs and air bladders 



2. Development of lungs 



a. Development of lungs in the frog and other Amphibia 

 h. Lung development in the chick 



1) General features of lung development 



2) Formation of air sacs 



3) Formation of the bronchi and respiratory areas of the chick's lung 



4) Trachea, voice box, and ultimate position of the bird's lung in the body 



5) Basic cellular composition of the trachea, lungs, and air sacs 

 c. Development of lungs in the mammal 



1) Origin of the lung rudiment 



2) Formation of the bronchi 



3) Formation of the respiratory area of the lung 



4) Development of the epiglottis and voice box 



5) Cellular composition 



6) Ultimate position of the mammalian lung in the body 



3. Development of air bladders 



4. Lunglessness 



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