266 BIOLOGY FOR BEGINNERS 



Essentials for digestive system. 



Tubular canal. 



Glands for secretion. 



Devices to increase surface, for osmosis absorption. 

 Circulation. 

 Heart, location, 



Three chambers, two auricles, one ventricle. 

 Arteries, carry blood from the heart. 



Carotid, from ventricle to head, oxygenated blood. 



Aorta, from ventricle to body, oxygenated blood. 



Pulmonary, from ventricle to lungs, de-oxygenated blood. 

 Veins, carry blood toward the heart. 



Portal-caval, from digestive system to right auricle, de-oxygenated. 



Caval, from muscles, etc., to right auricle, de-oxygenated. 



Pulmonary, from lungs to left auricle, oxygenated. 

 Blood changes in lungs, water, carbon dioxide, out, oxygen, in. 

 Blood changes in kidneys, water, urea, salts, out. 

 Blood changes in liver, impurities, bile, out, sugar changes. 

 Advance over fish. 



Three-chambered heart. 



Two circuits of blood, pulmonary and general. 



Lungs instead of gills. 

 Respiration. 



Gills in larval stage, lungs later. 

 Lungs, shape, location. 



Wall structure, air cells, and capillaries (why?). 

 Action of lungs in breathing. 



Air pumped into mouth by throat and swallowed. 



No diaphragm (cf. man). 



Air exchange in mouth, nostrils with valves. 

 Use of skin, how adapted for breathing. 

 Nervous System. 



Brain larger, specialized parts, nearly fills skull. 

 Spinal cord thicker, shorter, with specialized branches. 

 Senses better (Ex. taste). Higher intelligence (why?). 

 Excretion. Reproduction. 



Kidneys, shape, location. Ovaries. 



function. Sperm glands. 



Lungs and skin. Ducts. 



What excreted by each. 



