Respiratory System

• Respiration


  The process of oxygen uptake to the body and cell, while carbon dioxide leaves the cell and body

  
• Stages of human respiration

  1. Breathing

  2. External respiration

  3. Internal respiration

  4. Cellular respiration

  
• Breathing

  Involves breathing in (inspiration) and breathing out (expiration)
• External respiration


  The exchange of carbon dioxide and oxygen between the inspired air inside the lungs and the blood (gas exchange)

  
• Internal respiration


  The exchange of carbon dioxide and oxygen between the blood and the body's tissue cells
• Cellular respiration


  A series of chemical reactions that releases energy within the cell
• Respiratory surface


  • Must be large enough so that gas exchange can meet the body's needs
  • Must take place in a moist environment - in order for carbon dioxide and oxygen to be dissolved in water
• Ventilation


  The act of drawing/moving an oxygen-containing medium (water or air) over a respiratory surface

  
• Outer skin as respiratory surface

  Oxygen will diffuse through the skin and into the capillary network, while carbon dioxide will diffuse out of the capillary network, leaving through the skin
• Gills as respiratory surface


  Oxygen from the water will diffuse across the gills and into the capillaries, while carbon dioxide will diffuse out, towards the environment
• Tracheal system as respiratory surface


  Oxygen will enter the body through the spiracles, and diffuse into the tracheae - carbon dioxide will diffuse in the opposite direction
• Lungs as respiratory surface


  Oxygen diffuses across the epithelial lining into the capillaries, carbon dioxide travels in opposite direction
• Aquatic gas exchange


  Dissolved oxygen within the water will diffuse into the capillary system, while carbon dioxide will diffuse from the capillary network, across the gills, into the water
• Diffusion gradient


  A difference between concentrations that allows gas exchange to occur
• Counter-current exchange mechanism


  The blood and water flow in opposite direction, allowing the diffusion gradient to be continually high
• Inhalation


  Air is brought into the body, where gas exchange can then occur
• Exhalation


  Air is pushed out of the body
• Diaphragm


  A sheet of muscle that separates the thoracic cavity from abdominal cavity
• Intercostal muscles


  Muscles that are found near the rib cage
• Inhalation


  1. Intercostal muscles and diaphragm contract, moving the diaphragm downward

  2. Rib cage expands upward and outward

  3. Chest cavity volume increases, lung pressure decreases

  4. Air is drawn in

  
• Exhalation

  1. Intercostal muscles and diaphragm relax, moving the diaphragm upward

  2. Rib cage shrinks, moving inward

  3. Chest cavity volume decreases, lung pressure increases

  4. Air is pushed out

  
• Spirograph


  Used to visualize the amount of air that moves in and out of the lungs with each breath

  
• Spirograph features


  • Tidal volume
  • Inspiratory reserve volume
  • Expiratory reserve volume
  • Vital capacity
  • Residual volume
• Tidal volume


  The volume of air that is inhaled and exhaled in a normal breathing movement (assuming body is at rest)
• Inspiratory reserve volume


  The additional volume of air that can be taken into the lungs beyond a regular (tidal) inhalation

  
• Expiratory reserve volume


  The additional volume of air that can be forced out of the lungs beyond a regular (tidal) exhalation
• Vital capacity


  The total volume of gas that can be moved in or out of the lungs (forcefully)
• Residual volume


  The amount of gas that remains in the lungs and passageways even after a full exhalation
• Anatomy of Respiratory System

  1. Air enters mouth or nose

  2. Air warmed, moistened, and filtered in nasal passage

  3. Cilia trap foreign particles

  4. Air reaches pharynx

  5. Air enters larynx (voice box)

  6. Air passes through trachea

  7. Bronchi branch into lungs

  8. Bronchioles have alveoli

  9. Capillaries cover alveoli

  
• Glottis


  Valve between lungs and mouth, closed by epiglottis
• Vocal cords


  Two folds of membrane stretched across larynx, vibrate to produce sound
• Pleural membrane


  Double layered sac containing lubricating fluid, reduces friction between lungs and thoracic cavity
• Gas Exchange Within Humans

  1. Oxygen diffuses from alveoli into blood

  2. Carbon dioxide diffuses from blood into alveoli

  3. Oxygen-rich blood transports oxygen to tissue cells

  4. Carbon dioxide transported by hemoglobin

  
• Hemoglobin


  Protein in blood cells that contains iron and transports oxygen and carbon dioxide
• Respiratory Disorders


  • Tonsillitis
  • Laryngitis
  • Pneumonia
  • Bronchitis
  • Asthma
• Tonsillitis


  • Bacterial/viral infection of tonsils, symptoms are swollen tonsils, sore throat, fever, swollen neck glands
• Laryngitis


  • Inflammation of larynx caused by infection/allergy/overstraining of voice
• Pneumonia


  • Alveoli inflamed and filled with fluids, caused by bacterial/viral infections, treated with antibiotics
• Bronchitis


  • Bronchi inflamed and filled with mucus, can be short-term (bacterial) or long-term (COPD)
• Asthma


  • Bronchi and bronchioles become inflamed, muscles contract and cells produce more mucus, blocking airflow