Lung Structure and Breathing

• What is average human breathing rate?

  12 to 15 times a minutes
• How much is breathed in per breathed?

  500ml
• What is cellular respiration?

  Occurs within tissues and is breakdown of glucose to produce ATP. It requires oxygen and releases CO2
• How can the respiratiory be split?

  physiologically or anatomically
• what are the two anatomical splits of respiratory system?


  Upper and lower
• how many lobes does the right lung have?

  3
• why does the left lung have 2 lobes?

  has a section for the heart
• How many division from trachea?

  23
• What covers alveoli?


  capillary network
• what is in the upper respiratory system?


  Nose, Pharynx, Larynx
• What is the function of the nose?

  • Filtration of particles
  • Air passage
  • Smell
  • Humidifying air
  • Elimination of mucous (expectoration)
  • Warming air
• What is the function of Pharynx?

  • Food passage
  • Air passage
  • Elimination of mucous (expectoration)
  • Warming air
• what is the function of Larynx?

  • Vocalisation
  • Food passage
• What is present in the lower respiratory system?

  anything in the lungs
• What does Cili do?

  moves mucus out of lung
• What do goblet cells produce?


  secrete mucin
• what is cilli in the lungs refered?

  Mucociliary blanket
• Why is cold air a bad thing?

  Leads to the constriction of airways
• what does the mucociliary do?

  filtration
• what does the lack of goblet cells and cilli tell us?

  gas exchange takes place here
• What are the components of the physiological system?

  conducting zone, respiratory zone
• what is the role of conducting system?

  transfer of air into the lungs
• what is the role of the respiratory zone?


  Gas exchange between blood and air
• what is pulmonary ventilation?

  breathing
• what is used in normal 'quiet' breathing?


  Diaphram, internal and external intercostal
• What is used during forceful breathing?


  More muscles (this is the cause of forced breathing on exercise)
• What is alveolar pressure?

  760mmHg
• what is intrapleural pressure?

  756mmHg
• describe breathing at rest?

  diaphragm is relaxed and alveolar is equal to atmospheric pressure, and there is no air flow
• How does air move into lung?


  in response to changes or difference in pressure
• inhalation:

  1. Diaphragm contracts, external intercostal muscles contract
  2. Chest cavity and lung volume expand
  3. Alveolar pressure drops to 758mmHg
  4. Atmospheric pressure (760mmHg) is now higher than internal pressure
  5. Air is drawn in from high to low pressure
• Exhalation:

  1. Diaphragm and external intercostal muscles relax
  2. Lungs spring back (recoil) and chest cavity contracts
  3. Contraction increases alveolar pressure to 762mmHg
  4. Air flows out of lungs towards lower atmospheric pressure (760mmHg)
• What is boyles law?

  volume of a gas vaires inversely with pressure
• How to affect efficiency of pulmonary ventilation?

  • compliance
  • Surface tension
  • airway resistance
• What is compliance?


  How stretchy things are
• How does surface tension affect?

  surfactant reduces surface tension. Without it, alveoli would collapse
• Airway resistance:

  airflow: (P alveoli - P atmospher)/resistance
• where is ther respiratory centre?

  medulla oblongata and midbrain control breathing
• Where is the pontine respiratory centre?

  mid brain
• where is the dorsal respiratory group?

  in medulla