1. Lungs • The right and left lungs are soft, spongy, cone-shaped organs in the thoracic cavity • Contain the • These branch into smaller passageways called the • At the Summary of Respiratory System: http://glencoe.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/0015081981/512873/respiratory_system_over18.swf::Respiratory%20System%20Overview

2. Relationship Between Volume & Pressure • If • And vice versa… • Breathing occurs when the • When the volume of the lungs changes, • If the pressure is greater in the lungs than outside the lungs,

3. Four Events of Respiration • Pulmonary ventilation - • External respiration - • Respiratory gas transport - • Internal respiration -

4. Pulmonary Ventilation • Mechanical process that depends on volume and pressure changes in the thoracic cavity. • Causes the • 2 phases: • Inhalation: • External air is Animation of Pressure Changes: http://glencoe.mcgraw-hill.com/sites/0015081981/student_view0/chapter16/alveolar_pressure_changes_during_inspiration_and_expiration.html

5. Exhalation: • Largely a • Air is pushed out of the lungs due to this • Further Exhalation Inhalation

6. Lung Volumes & Capacities • Tidal volume (TV)- about 500 mL, • Inspiratory reserve volume (IRV) -about 3,100 mL,

7. Lung Volumes & Capacities • Expiratory reserve volume (ERV) - about 1,200 mL, • Residual volume (RV) - about 1,200 mL, • Total Lung Capacity –

8. External Respiration - Gas Exchange at Alveoli • Millions of alveoli clusters make up the lungs • Alveoli walls are • Gas exchange occurs by • Oxygen diffuses from • Carbon dioxide Pulmonary arteriole Bronchiole Blood flow Blood flow Capillary network on surface of alveolus Pulmonary Venule Pulmonary Arteriole Alveoli Alveoli O2 CO2 O2 CO2 Animation: http://glencoe.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/0015081981/512873/gas_exchange_during_res.swf::Gas%20Exchange%20During%20Respiration Capillary

9. Respiratory Gas Transport in the Blood: Oxygen • Most oxygen is attached to hemoglobin (Hb) in red blood cells. • A fully saturated hemoglobin molecule has • The ability of hemoglobin to bind to oxygen is influenced by • The following are three factors that decrease the strength of attractionof Hb for oxygen:

10. Respiratory Gas Transport in the Blood: Carbon Dioxide • Most carbon dioxide is transported in • The reaction for this process is: H2O + CO2 H2CO3  H+ + HCO3- • The H+in the blood

11. Carbon Monoxide Poisoning • Carbon monoxide poisoning occurs because there is • Carbon monoxide is an • Hemoglobin actually binds more readily with carbon monoxide to the extent that it displaces oxygen • Symptoms:

12. Neural Regulation of Breathing • Respiratory muscles are controlled by • Phrenic nerves • Irritation of the phrenic nerves leads to the • Neural centers that control rate and depth of breathing are located in the • Medulla - • Pons –

13. Neural Regulation of Breathing

14. Chronic Obstructive Pulmonary Diseases (COPD) • Common Features: