Lesson 11
1. Compare the location and design of the conducting airways and alveoli
Conducting airways
o Dead space that does not exchange air
o Nose/mouth, larynx, trachea, bronchi to carina and bronchioles
o 10 bronchial segments on the right, 8 on the left (self-contained
units)
Alveoli
o Tiny air sacs at the end of the bronchioles for diffusion of gases
o Large surface area
o Short distance between capillary and alveolus
o Gas moves from high concentration to low concentration,
ventilation exchanges gases
2. Explain how the lung develops and when surfactant is developed.
The lung is not fully developed until the 32nd to 36th weeks of life.
Type II alveolar cells (produce surfactant) are also developed at this time
3. List and discuss the 3 factors for gas exchange to occur.
Large surface area
Short distance between capillary and alveolus
Correct concentration gradients to promote movement of gases
o Ventilation exchanges gases
o From high concentration to low concentration
4. Identify the cell that produces surfactant and the purpose of surfactant.
Type II alveolar cell produces surfactant
Surfactant keeps the lung from collapsing when you exhale, keeps the
alveoli from closing all the way
5. Describe how inspiration and expiration occurs.
Inspiration
o Air enters the lung actively
o A vacuum is created with inspiration
Diaphragm drops, intercostals open creating negative
pressure in chest which pulls lung along
Expiration
o Air exits the lungs passively
o Elastic recoil in the diaphragm/ lung pushes air out
o Surfactant keeps the alveoli open with exhalation
,6. Draw a graph and label the volumes and capacities of the lung, demonstrate
where COPD, asthma and cystic fibrosis are using pulmonary function tests.
Normal volumes and capacities
COPD/Emphysema/Asthma (they are all obstructive diseases)
o This chart shows the expansion of IRV, VT and EV in patients with
emphysema (a form of obstructive lung disease). Note how the
ERV is not higher, because they lack the elastic recoil needed to
increase exhalation.
o PFT will reveal a compromised expiratory flow
Low FEV1, FVC, and FEV1/FVC ratio
, CF shows restrictive lung disease
o For restrictive lung disease, this chart shows the reductions in IRV
and RV. These patients cannot inhale easily, but due to the marked
elasticity of the lung they can exhale well.
o Low VC, FRC and TV
7. Compare and contrast compliance, recoil and resistance.
Compliance: ability to expand with inspiration, the opposite of stiffness
o The stiffer the lung, the less compliant
o Effected by 2 factors:
Elastic properties of the lung tissue
Surface tension within the lung
Noncompliant: CF
Compliant: Emphysema
Recoil: ability of the lung to collapse during exhalation, the same as
elasticity
o less recoil with emphysema
Resistance: the ease at which air flows into the lungs
o Higher resistance in smaller tubes
o Asthma would have greater resistance
8. Identify the protective functions of the lung.
Mucous lined airways
o Filters, humidifies, warms air
o Trap and destroy particulate/ infectious material
Cilia in airways
o Inhaled air follows non laminar flow
o Nasal cilia beat downward
o Airway cilia beat upward
Cough reflex
o Removes abnormal secretions, exudate, inflammatory products,
foreign bodies, irritating sensations
, Closure of airway during swallowing
o Cessation of breathing (brief)
o Receptors in laryngeal nerve
Activated by swallowing
Coordinate laryngeal closure and breathing
IgE and IgG in airways
o Allergic response
Fibroblasts and macrophages
o Interstitial spaces
9. Discuss perfusion and ventilation, listing examples of shunting and low and high
V/Q.
Ventilation (V): ventilation is the movement of air into and out of the lungs
Perfusion (Q): distribution of blood
Low V/Q: impaired ventilation, no impaired blood flow, leading to
hypoxemia
High V/Q: impaired perfusion, alveolar dead space
Shunting: if ventilation is absent and blood flow is not
10. Recall the process of viral infection and the role of mucus, the mucociliary
escalator and immune cells to combat it.
Mucus is produced from goblet cells in the sinuses and airway
Mucociliary escalator moves material up into pharynx for removal
11. Compare and contrast the three upper respiratory infections.
Acute Rhinosinusitis: inflammation of the lining of the paranasal sinuses
o Patho is related to 3 factors:
Obstruction of sinus drainage pathways (polyps, foreign
bodies, deviated septum, tumors)
Ciliary impairment (smoke, dehydration, anticholinergics,
antihistamines, cold air, bacteria)
Altered mucous quantity and quality
Viscosity, the thicker the mucous the more obstruction
to flow
Pharyngitis: viral inflammation of the upper airway
o Enter through the ciliated epithelium of the nose
o Edema and hyperemia of the nasal mucous membrane
o Increased mucus production and obstruction of the passages
o Viral differences:
Rhinovirus does not invade the pharynx
Adenovirus more common in children
Fever and conjunctivitis, does invade the pharynx
Epstein-Barr virus (infectious mononucleosis)
Invades tonsils and pharynx
1. Compare the location and design of the conducting airways and alveoli
Conducting airways
o Dead space that does not exchange air
o Nose/mouth, larynx, trachea, bronchi to carina and bronchioles
o 10 bronchial segments on the right, 8 on the left (self-contained
units)
Alveoli
o Tiny air sacs at the end of the bronchioles for diffusion of gases
o Large surface area
o Short distance between capillary and alveolus
o Gas moves from high concentration to low concentration,
ventilation exchanges gases
2. Explain how the lung develops and when surfactant is developed.
The lung is not fully developed until the 32nd to 36th weeks of life.
Type II alveolar cells (produce surfactant) are also developed at this time
3. List and discuss the 3 factors for gas exchange to occur.
Large surface area
Short distance between capillary and alveolus
Correct concentration gradients to promote movement of gases
o Ventilation exchanges gases
o From high concentration to low concentration
4. Identify the cell that produces surfactant and the purpose of surfactant.
Type II alveolar cell produces surfactant
Surfactant keeps the lung from collapsing when you exhale, keeps the
alveoli from closing all the way
5. Describe how inspiration and expiration occurs.
Inspiration
o Air enters the lung actively
o A vacuum is created with inspiration
Diaphragm drops, intercostals open creating negative
pressure in chest which pulls lung along
Expiration
o Air exits the lungs passively
o Elastic recoil in the diaphragm/ lung pushes air out
o Surfactant keeps the alveoli open with exhalation
,6. Draw a graph and label the volumes and capacities of the lung, demonstrate
where COPD, asthma and cystic fibrosis are using pulmonary function tests.
Normal volumes and capacities
COPD/Emphysema/Asthma (they are all obstructive diseases)
o This chart shows the expansion of IRV, VT and EV in patients with
emphysema (a form of obstructive lung disease). Note how the
ERV is not higher, because they lack the elastic recoil needed to
increase exhalation.
o PFT will reveal a compromised expiratory flow
Low FEV1, FVC, and FEV1/FVC ratio
, CF shows restrictive lung disease
o For restrictive lung disease, this chart shows the reductions in IRV
and RV. These patients cannot inhale easily, but due to the marked
elasticity of the lung they can exhale well.
o Low VC, FRC and TV
7. Compare and contrast compliance, recoil and resistance.
Compliance: ability to expand with inspiration, the opposite of stiffness
o The stiffer the lung, the less compliant
o Effected by 2 factors:
Elastic properties of the lung tissue
Surface tension within the lung
Noncompliant: CF
Compliant: Emphysema
Recoil: ability of the lung to collapse during exhalation, the same as
elasticity
o less recoil with emphysema
Resistance: the ease at which air flows into the lungs
o Higher resistance in smaller tubes
o Asthma would have greater resistance
8. Identify the protective functions of the lung.
Mucous lined airways
o Filters, humidifies, warms air
o Trap and destroy particulate/ infectious material
Cilia in airways
o Inhaled air follows non laminar flow
o Nasal cilia beat downward
o Airway cilia beat upward
Cough reflex
o Removes abnormal secretions, exudate, inflammatory products,
foreign bodies, irritating sensations
, Closure of airway during swallowing
o Cessation of breathing (brief)
o Receptors in laryngeal nerve
Activated by swallowing
Coordinate laryngeal closure and breathing
IgE and IgG in airways
o Allergic response
Fibroblasts and macrophages
o Interstitial spaces
9. Discuss perfusion and ventilation, listing examples of shunting and low and high
V/Q.
Ventilation (V): ventilation is the movement of air into and out of the lungs
Perfusion (Q): distribution of blood
Low V/Q: impaired ventilation, no impaired blood flow, leading to
hypoxemia
High V/Q: impaired perfusion, alveolar dead space
Shunting: if ventilation is absent and blood flow is not
10. Recall the process of viral infection and the role of mucus, the mucociliary
escalator and immune cells to combat it.
Mucus is produced from goblet cells in the sinuses and airway
Mucociliary escalator moves material up into pharynx for removal
11. Compare and contrast the three upper respiratory infections.
Acute Rhinosinusitis: inflammation of the lining of the paranasal sinuses
o Patho is related to 3 factors:
Obstruction of sinus drainage pathways (polyps, foreign
bodies, deviated septum, tumors)
Ciliary impairment (smoke, dehydration, anticholinergics,
antihistamines, cold air, bacteria)
Altered mucous quantity and quality
Viscosity, the thicker the mucous the more obstruction
to flow
Pharyngitis: viral inflammation of the upper airway
o Enter through the ciliated epithelium of the nose
o Edema and hyperemia of the nasal mucous membrane
o Increased mucus production and obstruction of the passages
o Viral differences:
Rhinovirus does not invade the pharynx
Adenovirus more common in children
Fever and conjunctivitis, does invade the pharynx
Epstein-Barr virus (infectious mononucleosis)
Invades tonsils and pharynx
