THE RESPIRATORY SYSTEM 197 



LABORATORY STUDIES AND SUGGESTIONS 



1. Of what four elements are the soft parts of the body largely composed? 



2. What waste gas is formed in every part of the body exercised? 



3. Through what three channels do waste materials pass from the blood? 



4. Describe the manner in which the oxygen of the air reaches the blood? 



5. Write a description of the pharynx. 



6. Bisect the larynx in the sagittal plane, make a drawing of the cut aspect, 

 and label all features. 



7. How many cartilaginous rings in the trachea and what is their use? 



8. Describe as much of the pleura as can be seen in your specimen. 



9. Do the right and left bronchi have the same number of main branches? 



10. Why do the air cells seldom become clogged? 



11. What muscles are largely used in respiration? 



12. Describe the hyoid bone as seen from your dissection. 



13. What part of this bone can 3'ou feel beneath your mandible? 



14. How does the carbon dioxid given off by the cells in the foot reach the 

 lungs? 



15. What causes the air to enter the lungs? 



16. Inflate the lungs of a freshly killed animal by forcing air from your lungs 

 into a glass tube tied into its trachea. 



17. After retaining a full inspiration of air as long as possible, expire it through 

 a glass tube into the bottom of a two-liter bottle and insert into the bottle a 

 lighted splinter. 



18. Describe the pulmonary circulation. 



