BIOLOGY 12: UNIT J - CHAPTER 15 - REVIEW WORKSHEET RESPIRATORY SYSTEM A. CHAPTER REVIEW 1. Define the four components of respiration. 2. What happens to the air as it moves along the air passages? What happens to the air as it is expired? 3. How do we get a sinus headache? What tube leads into the nasopharynx from the middle ears? 4. What two passages temporarily join in the pharynx? 5. Name the opening at the top of the larynx. Why doesn t food enter the glottis when food is swallowed? 6. What factors determine the pitch of the voice? The loudness of the voice? 7. What is the function of the C-shaped cartilaginous rings in the trachea? 8. What is the function of the cilia in the trachea? 9. What is the purpose of a tracheostomy? 10. As the bronchial tubes subdivide, what happens to their walls? What is an alveolus? 11. Describe what happens in infant respiratory distress syndrome. 12. Explain why intrapleural pressure needs to be less than the atmospheric pressure during inspiration. 13. What are the three primary stimuli that trigger breathing? 1
14. What happens when the respiratory centre sends out nerve impulses to the diaphragm and the rib cage? 15. Is inspiration an active or passive process? Why is it said that humans breathe by negative pressure (p. 288) 16. What causes air to be pushed out during expiration? 17. Although expiration is normally a passive process, when can it become an active process? 18. Define the following terms: tidal volume, vital capacity, inspiratory reserve volume, expiratory reserve volume, and residual volume. Also provide their average volumes, 19. What is the average total lung capacity of an adult human? 20. Specifically where does external respiration occur? What process governs gas exchange at this site? What structural and physical features allow for this exchange to occur? 21. Why does CO2 diffuse out of the blood into the alveoli? In what medium is most of the CO2 being carried to the lungs? 22. What happens to hemoglobin in the blood when the partial pressure of O2 increases in the lungs? How does this relate to temperature and ph? 23. Why does O2 diffuse out of the blood and into the tissue during internal respiration? 24. What is the role of carbonic anhydrase in red blood cells at the tissue site? 25. How is carbon dioxide transported in the blood? Which is the most abundant way for CO2 transport? 2
26. Why is it important for hemoglobin to combine with excess hydrogen ions? B. COMPLETION AND SHORT ANSWER QUESTIONS 1. The two processes involved in breathing are and. 2. Fill in the blanks to describe the path that air takes in sequence: nasal cavities larynx bronchi alveoli. 3. During inspiration, the rib cage moves up and ; the diaphragm moves. 4. The primary (main) stimulus for breathing is the amount of in the blood. 5. Oxygen moves from the alveoli to the capillaries by means of. 6. Carbon dioxide is carried primarily in the plasma as ions. 7. Hemoglobin readily takes up oxygen in the lungs where the ph is and the temperature is (cool, warm, hot) 8. At the tissues, diffuses out of the blood and (2 words) diffuses into the blood. 10. a) When food is swallowed, the respiratory passage is closed off. How are the nasal passages closed off? b) How is the trachea/larynx closed off? 12. Indicate whether the following phrases describe inspiration (I) or expiration (E). lungs are expanded muscles in the diaphragm and ribcage are relaxed diaphragm has a dome shape chest is enlarged there is less air pressure in the lungs than in the atmosphere 13. Put the following statements into the proper sequence, beginning with inspiration. A. Respiratory centre stops sending messages to the diaphragm and rib muscles. B. Respiratory centre sends excitatory messages to the diaphragm and rib muscles. C. Diaphragm becomes dome-shaped and rib muscles relax. D. Chest expands as diaphragm goes down and rib cage goes out. E. Air goes rushing out as lungs recoil. F. Air comes rushing in as lungs expand. G. Expanded lungs send message to respiratory centre. Sequence: 14. Refer to the diagram Figure 15.8 (External and internal respiration) on page 291. a) Where does oxygen enter the blood? b) Where does oxygen exit from the blood? c) Where does carbon dioxide enter the blood? d) Where does carbon dioxide exit from the blood? 3
e) Which blood vessel is HIGH in [oxygen]? f) Which blood vessel is LOW in [oxygen]? 15. Transport of Gases (refer to p. 290) a) Give the overall equation that describes how oxygen is transported by hemoglobin in the blood. Use a double arrow ( ); label one arrow lungs and the other tissues. b) Give the overall equation that describes how most of the carbon dioxide is transported in the blood. Label one arrow lungs and the other tissues. 16. The enzyme that speeds up the reaction in question in 15b is. 17. Carbon dioxide transport produces hydrogen ions. Why does the blood NOT become acidic? 18. Hemoglobin is remarkably suited to the transport of oxygen. Why? 19. How does hemoglobin help with the transport of carbon dioxide? 20. The name of an instrument used to measure the amount of air that can be maximally inhaled and exhaled is a. 21. The operation used to place a tube inside the trachea is termed a. C. TRUE/FALSE QUESTIONS If the statement is false, rewrite the statement as a true one. 1. Diffusion of gases occurs in the lungs but not in the tissues. 2. The trachea is held open by cartilaginous rings so that food can pass down more easily. 3. The glottis is covered over by the epiglottis during swallowing. 4. The alveolus is a thin-walled air sac surrounded by thick-walled capillaries. 4
5. The thoracic cavity and lungs are separated by a fluid-filled space that has a positive pressure. 6. Chemoreceptors found in the carotid and aortic bodies communicate with the respiratory centre in the cerebrum. 7. When the lungs are expanded, the respiratory centre is inhibited by nerve impulses from the alveolar walls. 8. The direction in which gases move between the lungs and the blood is determined by temperature. 9. When hemoglobin is combined with oxygen, it tends to be bright red in colour. 10. The pleural membrane is a sheet of muscle that separates the chest cavity from the abdominal cavity in humans. 5