RESPIRATORY

• Respiratory system


  The system responsible for the exchange of gases that occurs during respiration

  
• Major functions of the respiratory system

  • Supply oxygen to cells
  • Remove carbon dioxide from cells

  
• Major organs of the respiratory system

  • Nose
  • Pharynx
  • Larynx
  • Trachea
  • Main (primary) bronchi
  • Lobar bronchi
  • Terminal bronchioles
  • Respiratory bronchioles
  • Alveolar ducts
  • Alveolar sacs
  • Lungs

  
• External respiration

  Gas exchange between the air in the alveoli and the blood in the pulmonary capillaries

  
• Internal respiration

  Gas exchange between the blood and the body's cells

  
• Pulmonary ventilation

  The movement of air into and out of the lungs

  
• Volumes of air exchanged during pulmonary ventilation

  • Tidal volume
  • Vital capacity

  
• Mechanisms that regulate respiration

  • Respiratory center in the brain stem
  • Carotid and aortic bodies monitoring blood O2 and CO2 levels

  
• Conducting zone


  Part of the respiratory system that brings air into and out of the lungs

  
• Respiratory zone


  Part of the respiratory system where gas exchange occurs

  
• Cells in the conducting zone

  • Goblet cells secrete mucus
  • Ciliated columnar cells have cilia that move mucus
• Cells in the respiratory zone

  • Type I pneumocytes line the alveoli
  • Type II pneumocytes secrete surfactant

  
• Surfactant reduces surface tension and prevents alveolar collapse
• Extensive branching of alveoli produces large surface area for gas exchange
• Alveolar and capillary walls are thin, allowing rapid diffusion of gases
• Aerobic energy production

  1. Oxygen is required

  2. Carbon dioxide is produced

  3. ATP is produced
• Integrated processes of respiration

  • Pulmonary ventilation
  • Gas exchange
  • Transport of oxygen and carbon dioxide
  • Internal respiration

  
• Gas exchange

  The exchange of oxygen and carbon dioxide between the air and the blood
• Gas transport

  The transport of oxygen and carbon dioxide in the blood
• Internal respiration

  The exchange of oxygen and carbon dioxide between the blood and the body's cells

  
• Diffusion is the mechanism for gas exchange in the respiratory zone

  
• Hemoglobin and bicarbonate transport oxygen and carbon dioxide in the blood
• Intrapleural pressure

  The pressure inside the pleural sac, which is negative relative to atmospheric pressure
• Intrapleural pressure

  Drives the movement of air into and out of the lungs during ventilation
• Spirometry measures lung volumes and capacities
• Dalton's law


  The total pressure of a gas mixture is equal to the sum of the partial pressures of each gas
• Oxygen and carbon dioxide diffuse down their concentration gradients in the lungs

  
• Hemoglobin

  Transports oxygen bound to it in the blood
• Carbon dioxide transport

  • Dissolved in plasma
  • As bicarbonate
  • Bound to proteins (carbamino compounds)
• Control of breathing

  • Respiratory center in the brainstem
  • Carotid and aortic bodies monitor blood O2 and CO2 levels