Download - Ch 13 Development Disorders
Chapter 13The
Respiratory System
External RespirationExternal Respiration
1. Oxygen movement into the blood
alveoli have more O2
O2 moves by diffusion
Pulmonary capillary blood gains O2
2. CO2 movement out of the blood
Blood has more CO2
Pulmonary capillary blood gives up CO2
Blood leaving the lungs is O2 -rich and CO2- poor.
Which is Internal or External Respiration?Which is Internal or External Respiration?
Figure 13.11
Respiratory Disorders: Respiratory Disorders: 1. Chronic Obstructive Pulmonary Disease (COPD)1. Chronic Obstructive Pulmonary Disease (COPD)
Exemplified by chronic bronchitis & emphysema
Major causes of death & disability in US
Features
-history of smoking
-Labored breathing (dyspnea)
-Coughing & frequent infections
-Retain carbon dioxide
- are hypoxic & have respiratory acidosis
-Ultimately develop respiratory failure
EmphysemaEmphysema Alveoli enlarge as chambers break through
Chronic inflammation promotes lung fibrosis
Airways collapse during expiration
Much energy to exhale
Overinflation leads to a barrel chest
Cyanosis appears late in the disease
Chronic BronchitisChronic Bronchitis Mucosa of respiratory
passages becomes severely inflamed
Mucus production increases
Pooled mucus impairs ventilation and gas exchange
Risk of lung infection increases
Pneumonia is common
Hypoxia and cyanosis occur early
Chronic Obstructive Pulmonary Disease (COPD)Chronic Obstructive Pulmonary Disease (COPD)
Figure 13.13
Lung CancerLung Cancer Accounts for 1/3 of all
cancer deaths in the United States
Increased incidence associated with smoking
Three common types
- Squamous cell carcinoma
- Adenocarcinoma
- Small cell carcinoma
Sudden Infant Death syndrome (SIDS)Sudden Infant Death syndrome (SIDS) Apparently healthy
infant stops breathing and dies during sleep
Some cases are thought to be a problem of the neural respiratory control center
One third of cases appear to be due to heart rhythm abnormalities
AsthmaAsthma Chronic inflamed
hypersensitive bronchiole passages
Response to irritants with dyspnea, coughing, and wheezing
Developmental AspectsDevelopmental Aspects Lungs filled with fluid in the baby
Lungs not inflated until 2 weeks after birth
Surfactant that lowers alveolar surface tension is not present until late in fetal development and may not be present in premature babies
Developmental AspectsDevelopmental AspectsImportant birth defects
Cystic fibrosis – oversecretion of 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
Aging EffectsAging Effects Elasticity of lungs
decreases
Vital capacity decreases
Blood oxygen levels decrease
Stimulating effects of carbon dioxide decreases
More risks of respiratory tract infection