1. Chapter 13 Respiratory Sys – Disorders & Development

2. Respiratory Disorders: 1. Chronic Obstructive Pulmonary Disease (COPD)  Chronic bronchitis & Emphysema  Major causes of death & disability in US  Features - History of smoking -Labored breathing (dyspnea) -Coughing & frequent infections -Retain carbon dioxide -Hypoxia & respiratory acidosis -Ultimately develop respiratory failure

3. Emphysema Emphysema  Alveoli enlarge as chambers break  Chronic inflammation promotes lung fibrosis  Airways collapse during expiration  Much energy to exhale  Over-inflation leads to a barrel chest  Cyanosis appears late in the disease

4. Chronic Bronchitis  Mucosa of respiratory passages becomes inflamed  Mucus production increases  Pooled mucus impairs ventilation and gas exchange  Risk of lung infection  Pneumonia is common  Hypoxia and cyanosis occur early

5. Chronic Obstructive Pulmonary Disease (COPD) Figure 13.13

6. Lung Cancer  1/3 of all cancer deaths in the U.S.  Smoking = incidence  Three common types -Squamous cell carcinoma -Adenocarcinoma -Small cell carcinoma

7. Sudden Infant Death syndrome (SIDS)  Apparent healthy infant stops breathing and dies during sleep  Possible problem of neural respiratory control center  One third of cases appear to be due to heart rhythm abnormalities

8. Asthma  Chronic inflamed hypersensitive bronchiole passages  Response to irritants with dyspnea, coughing, and wheezing

9. Developmental Aspects  Fetal lungs filled with fluid  Not inflated til 2 weeks after birth  Surfactant that lowers alveolar surface tension not present until late fetal development; may not be present in premature babies

10. Developmental Aspects Important birth defects  Cystic fibrosis – thick mucus clogs the respiratory system  Cleft palate  Newborns – 40 to 80 rpm  Infants – 30 rpm  Age 5 – 25 rpm  Adults – 12 to 18 rpm  Rate increases with old age Respiratory Rate Changes Through Life

11. Aging Effects  Elasticity of lungs  Vital capacity  Blood oxygen levels  Controlling effects of carbon dioxide  Respiratory tract infection