The Respiratory System

• Hemoglobin - A molecule in RBC’s that transports O2 and CO2 molecules from the lungs to cells. It’s a protein.
• Respiratory System Functions:

  1. Breathing - inhalation / exhalation
  2. Ventilation - bringing gases across a respiratory surface (alveoli)
  3. Respiration - exchanging mostly O2 & CO2.

  - External (alveoli + blood)

  - Internal (blood + cells)

  - Cellular (cytoplasm + mitochondria)

  4. Protection - removal of pollutants from air (nose hairs, mucus), humidifying + warming air (turbinate bones)
• Inhalation:

  High volume to lower pressure, ribs up diaphragm down

  
• Exhalation:

  High pressure in lungs to low pressure outside

  
• Spirometry:

  Total Lung volume is 6000mL, vital capacity + residual volume

  
• Nasal cavity

  Pharynx

  Epiglottis - a flap that covers the trachea to prevent food from going into the lungs

  Larynx - voice box

  Trachea - lined with bones that are shaped like rings to prevent closure of the airway to the lungs

  Bronchus - primary, secondary, tertiary

  Bronchioles

  Alveoli - sac like, external respiration
• Ribs protect the lungs and move to force air in or out
• Alveoli are surrounded by capillaries (tiny blood vessels) where O2 moves into the blood and CO2 out of the blood and into airspace to be exhaled !EXTERNAL RESPIRATION!
• Oxygen being released by hemoglobin into red blood cells and diffusing into mitochondria
• Cellular Respiration:

  glucose + oxygen -> carbon dioxide + water
• What are the 2 requirements for respiration?


  A large enough respiratory surface to meet the body’s needs and a moist surface so O2 and CO2 can dissolve
• What surrounds the lungs?

  Plural membrane
• What does plural fluid do?

  Decreases friction and adheres lungs to ribs THEREFORE SMOOTH LUNG CONTRACTIONS
• What are the 4 types of respiratory surfaces?

  Lungs, gills, trachea, outer skin
• During inhalation, intercostals contract, lifting rib cage up and out. At the same time the diaphragm contracts and pulls downwards. This increases volume in the thoracic cavity so there’s low pressure in the lungs and air rushes in
• External respiration is when..

  O2 in capillaries, CO2 out
• Internal respiration is when…


  CO2 in capillaries, O2 out
• How is oxygen transported in the blood?

  By binding to iron containing pigment in hemoglobin that is found in RBC’s
• How is Carbon Dioxide transported?


  Being bound to hemoglobin / dissolved in plasma
• Why is inspiration considered and active phase and expiration is passive?

  Inspiration is active because diaphragm and muscles contract.

  Expiration is passive because diaphragm and intercostals relax
• What are the functions of the nasal passage 


  Warms, moistens (turbinate bones) and filters inhaled hair (nose hairs)