1. tiny sacs within the lungs which increase the surface available for gas exchange = alveoli 2. a digestive enzyme that breaks down starches and glycogen into sugars = amylase 3. the two thin-walled chambers that receive blood into the heart from the veins = atria 4. the two tubes into which the trachea divide to go into each lung = primary bronchi 5. a tiny vessel through which diffusion takes place between the blood and the body tissues = capillary 6. a mass of nerve tissue not part of the brain = ganglion
