Chapter 13 The Respiratory System

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Chapter 13The Respiratory System
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• Respiratory Sounds

• Monitored with stethoscope
• Bronchial sounds air in trachea and bronchi
• Vesicular sounds air filling alveoli

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• Gas Transport in the Blood

• 1. Oxygen transport
• Most carried in RBCs on hemoglobin
• Some dissolved in plasma

• 2. Carbon dioxide transport
• Most in plasma as bicarbonate ion (HCO3)
• Some carried in RBCs on hemoglobin.

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• Respiration Summary

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• Neural Regulation

• Phrenic intercostal nerves
• Medula - controls rate depth
• Pons - smoothes out respiratory rate
• Eupnea - normal rate 1215 rpm
• Hypernia - increased respiratory rate often due
  to extra oxygen needs

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• Factors Influencing Rate and Depth

• 1. Physical factors
• Increased body temperature
• Exercise
• Talking
• Coughing
• 2. Volition (conscious control)
• 3. Emotional factors

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• 4. Chemical factors
• a. CO2 levels
• Blood CO2 is main regulatory system
• CO2 respiration
• Changes in CO2 act on medulla oblongata

• b. O2 levels
• Changes detected by chemoreceptors in aorta and
  carotid artery
• Information sent to medulla oblongata

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Chapter 13 Respiratory Sys Disorders
Development
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• 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

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• 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

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• 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

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• Chronic Obstructive Pulmonary Disease (COPD)

Figure 13.13
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• Lung Cancer

• 1/3 of all cancer deaths in the U.S.
• Smoking incidence
• Three common types
• Squamous cell carcinoma
• Adenocarcinoma
• Small cell carcinoma

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• 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

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• Asthma

• Chronic inflamed hypersensitive bronchiole
  passages
• Response to irritants with dyspnea, coughing, and
  wheezing

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• 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

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• Developmental Aspects

• Important birth defects
• Cystic fibrosis thick mucus clogs the
  respiratory system
• Cleft palate

Respiratory Rate Changes Through Life

• Newborns 40 to 80 rpm
• Infants 30 rpm
• Age 5 25 rpm
• Adults 12 to 18 rpm
• Rate increases with old age

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• Aging Effects

• Elasticity of lungs
• Vital capacity
• Blood oxygen levels
• Controlling effects of carbon dioxide
• Respiratory tract infection