VPHY 3100 Respiratory Physiology
Ventilation - ANSWERSMoving air in and out of the respiratory system
External respiration - ANSWERSgas exchange between air and capillaries in lungs
Internal respiration - ANSWERSgas exchange between systemic capillaries and tissues of the body, pressure
gradients generate diffusion
Conducting zone - ANSWERSoutside the lungs - nasal passages --> pharynx --> epiglottis --> larynx (glottis)
Inside the lungs - yrachea --> bronchus (2 branches) --> bronchiole --> terminal bronchiole.
No gas exchange in conducting zone
Respiratory zone - ANSWERSrespiratory bronchioles, alveolar ducts, alveolar sacs
What happens to individual airway diameter and length as you go deeper into the lungs? Collective x-sectional
area? - ANSWERSDiameter and length decreases. Total cross sectional areas increases
Functions of the conducting zone - ANSWERSPassage of air, warming, humidification, filtration, immune
surveillance
mucociliary apparatus - ANSWERSMovement of mucus w/ dust particles out of the lungs
Functions of respiratory zone - ANSWERSGas exchange, passage of air, immune surveillance
Gas exchange in the lungs - ANSWERSOxygenated blood is transported by branches of the pulmonary vein to
the heart. Deoxygenated blood is transported by the branches of the pulmonary artery to the lungs and aveoli.
Gas exchange with blood only occurs in aveoli
Alveoli - ANSWERSSite of gas exchange. ~300x10^6. 0.25-0.5 mm in diameter. Total area = 60 - 80 m^2
, Alveolar Wall - ANSWERSType 1 Alveolar cells - the major lining cells, accounts for 95-97% of the total surface
area
Type 2 alveolar cells - production of surfactants
Air blood barrier - ~0.3 um
Layers of respiratory membrane - ANSWERS1. fluid layer with surfactant
2. Type 1 alveolar cell membranes
3. narrow interstitial space
4. capillary endothelial cell membranes
Thoracic Cavity - ANSWERSSurrounded by the rib cage (chest wall) and respiratory muscles
Pleural (intrapleural) space - ANSWERSThin fluid layer between visceral pleura covering lungs (visceral) and
parietal pleura lining thoracic cavity walls.
Air free, potential space --> lungs cling to inside of thorax
Diaphragm - ANSWERSMuscle between thoracic and abdominal cavities
Mediastinum - ANSWERSseparates two sides of the lungs
Quiet inspiration - ANSWERSActive process
1. contraction of diaphragm --> increase in thoracic volume vertically
2. Parasternal and external intercostals contract --> raising the ribs --> increase in thoracic volume laterally
(horizontally)
Quiet expiration - ANSWERSpassive process, relaxation of inspiratory muscles
Forced expiration - ANSWERSActive process, assisted by the abdominal muscles
Pulmonary innervation - ANSWERSSomatic NS: innervates diaphragm and intercostal muscles
Ventilation - ANSWERSMoving air in and out of the respiratory system
External respiration - ANSWERSgas exchange between air and capillaries in lungs
Internal respiration - ANSWERSgas exchange between systemic capillaries and tissues of the body, pressure
gradients generate diffusion
Conducting zone - ANSWERSoutside the lungs - nasal passages --> pharynx --> epiglottis --> larynx (glottis)
Inside the lungs - yrachea --> bronchus (2 branches) --> bronchiole --> terminal bronchiole.
No gas exchange in conducting zone
Respiratory zone - ANSWERSrespiratory bronchioles, alveolar ducts, alveolar sacs
What happens to individual airway diameter and length as you go deeper into the lungs? Collective x-sectional
area? - ANSWERSDiameter and length decreases. Total cross sectional areas increases
Functions of the conducting zone - ANSWERSPassage of air, warming, humidification, filtration, immune
surveillance
mucociliary apparatus - ANSWERSMovement of mucus w/ dust particles out of the lungs
Functions of respiratory zone - ANSWERSGas exchange, passage of air, immune surveillance
Gas exchange in the lungs - ANSWERSOxygenated blood is transported by branches of the pulmonary vein to
the heart. Deoxygenated blood is transported by the branches of the pulmonary artery to the lungs and aveoli.
Gas exchange with blood only occurs in aveoli
Alveoli - ANSWERSSite of gas exchange. ~300x10^6. 0.25-0.5 mm in diameter. Total area = 60 - 80 m^2
, Alveolar Wall - ANSWERSType 1 Alveolar cells - the major lining cells, accounts for 95-97% of the total surface
area
Type 2 alveolar cells - production of surfactants
Air blood barrier - ~0.3 um
Layers of respiratory membrane - ANSWERS1. fluid layer with surfactant
2. Type 1 alveolar cell membranes
3. narrow interstitial space
4. capillary endothelial cell membranes
Thoracic Cavity - ANSWERSSurrounded by the rib cage (chest wall) and respiratory muscles
Pleural (intrapleural) space - ANSWERSThin fluid layer between visceral pleura covering lungs (visceral) and
parietal pleura lining thoracic cavity walls.
Air free, potential space --> lungs cling to inside of thorax
Diaphragm - ANSWERSMuscle between thoracic and abdominal cavities
Mediastinum - ANSWERSseparates two sides of the lungs
Quiet inspiration - ANSWERSActive process
1. contraction of diaphragm --> increase in thoracic volume vertically
2. Parasternal and external intercostals contract --> raising the ribs --> increase in thoracic volume laterally
(horizontally)
Quiet expiration - ANSWERSpassive process, relaxation of inspiratory muscles
Forced expiration - ANSWERSActive process, assisted by the abdominal muscles
Pulmonary innervation - ANSWERSSomatic NS: innervates diaphragm and intercostal muscles
