respiration lec

• Respiration is the processes involved in: 

  • Oxygen (O2 ) transport from the atmosphere to the body tissues 
  • Release and transportation of carbon dioxide (CO2 ) produced by the tissues to the atmosphere 
• Respiration involves 2 processes: 

  • External respiration (pulmonary gas exchange)  
  • Internal (tissue) respiration 
• Buildup of CO2 makes our blood more acidic ]#
• The left lung is smaller than the right due to the heart being more positioned on the left side 

  Lower lobes are the largest part of the lung and sit posteriorly  
• The pleurae: 

  • A thin double layered serous membrane  
  • Parietal pleura – lines the thoracic wall and the diaphragm  
  • Visceral pleura – lines the surface of the lungs and fissures (divides lobes) 
  • This double layer creates a potential space (the pleural cavity) 
• The Thoracic Cage: 

  • Cone shaped  
  • Made up of 

    - thoracic vertebrae dorsally 

    - ribs laterally  

    - sternum and costal cartilages anteriorly  

   

  • Primary function is protective 
  • Secondary functions 

    - movement   

    - support (scapulae and UL’s) 

    - muscle attachment points 
• Ribs: 

  • 12 pairs 
  • Attach posteriorly to the thoracic vertebrae 
  • Slope inferiorly as curve anteriorly  
  • True ribs 1 to 7  
  • False ribs 8 to 10  
  • Floating ribs 11 & 12  
  • Increase in length from pair 1-7 
  • Decrease in length from pair 8 –12 
• costovertebral joint:

  between the head of the rib and the vertebral body
• costotransverse joint:

  between the rib tubercle and transverse process
• Movement of the ribs: 

  • For respiration to occur dimensions of the thorax must change 
  • Ribs 1 to 5 move in a pump handle fashion to increase AP diameter of thorax 
  • Ribs 8 to 10 move in a bucket handle fashion to increase lateral diameter of thorax 
• Pump handle ribs move in an upwards, ap direction with the sternum 

  Bucket handle ribs move in an upwards and outwards direction increasing the lateral diameter of the thorax