PHGY 216- MODULE 3 EXAM
QUESTIONS & ANSWERS
External Respiration Steps - Correct Answers -1. Ventilation
2. exchange of O2 and CO2 between air and blood
3. Transport of O2 and CO2.
4. Exchange of O2 and CO2 between blood and tissue.
Upper Tract - Correct Answers -Nose --> nasal cavity --> pharynx --> larynx
Lower tract - Correct Answers -trachea --> main bronchus -->bronchus -->bronchiole -->
terminal bronchiole -->Respiratory bronchiole -->alveolar duct --> alveolar wall
muscles of inspiration - Correct Answers -diaphragm, external intercostal muscles
muscles of expiration - Correct Answers -internal intercostal muscles , abdominal
muscles
pleural space - Correct Answers -between 2 membranes, lung covered by this, pleural
fluid fills it, allows membranes to rub against each other without causing friction
Respiration- 2 Processes - Correct Answers -1. Generating pressure gradient to move
air through airways
2. ability of O2 and CO2 to diffuse across alveolar-capillary barrier (pressure in alveoli
must be less then pressure in nose for air to flow down to alveoli)
VC - Correct Answers -vital capacity: max volume of air that can be expelled during
single breath following maximal inspiration (4500mL= IRV+ Vt+ERV)
TLC - Correct Answers -total lung capacity: max volume of air lungs can hold (5700mL=
VC+RV)
FEV1 - Correct Answers -forced expiratory volume in one second: derived only from 1st
second of expiratory effort. Normally expressed as ratio (FEV1/FVC), converted to %
Respiration Formula - Correct Answers -delta Pressure/ resistance = flow (diffussion)
Atmospheric Pressure (Pa) - Correct Answers -760mmHg at sea level, 0 remains
contast throughout body, decreases are altitude gained
, Alveolar Pressure (PA) - Correct Answers -pressure in alveoli, at end of inspiration,
alveolar pressure is the same as atmospheric pressure
Pleural Pressure (Ppl) - Correct Answers -pressure in pleural space, negative to
atmospheric pressure (because lungs want to collapse, yet chest wall wants to expand)
Transpulmonary Pressure (Ptp) - Correct Answers -Difference between alveolar
pressure and plerual pressure, also known as lung recoil pressure
Elastic Recoil in Lungs- 2 methods - Correct Answers -1. Elastin fibres: connective
tissue of lungs contain these, inhalation causes lungs to stretch, elastic recoil causes
lungs to contract
2. Surface tension- 70% of recoil properties, liquid layer resists forces, water molecules
are strong and resist being pulled apart
Alveolar Stability - 2 methods - Correct Answers -1. Pulmonary Surfactant- type 2
alveolar cells secrete lipids, dispersing water, reducing attraction, increased compliance
= decreased surface tension
2. Alveolar Interdependence- alveolus collapses , surrounding alveoli are stretched,
when they recoil, they pull outward on collapsed alveolus
Law of LaPlace - Correct Answers -2T (Surface tension)/ r (alveolar radius)= P
(collapsing pressure)
Alveolar Pressure Equation - Correct Answers -Alveolar Pressure (PA)- Pleural
Pressure (Ppl)= Lung Recoild Pressure (Pl)
Inflation and Exhalation - Correct Answers -- result of change in pleural and alevolar
pressure
1. Before inspiration= no flow, alveolar pressure= atmospheric pressure
2. During inspiration= pressure gradient established from atmosphere to alveoli
3. Ending inspiration= inspiratory muscle contraction decreases, elastic recoil pressure=
pleural pressure
4. EXPIRATION STARTS WHEN INSPIRATORY MUSCLES STOP CONTRACTING
Process of Inhalation and Exhalation (3 Steps) - Correct Answers -1. Onset of
Inhalation: alveolar pressure=atmospheric pressure, contraction causes decreased
pleural pressure, enlarges thoracic cavity, air flows down pressure gradient INTO lungs,
continues until alveolar pressure= atmospheric pressure again
2. Onset of Exhalation: end of inspiration when inspiratory muscles relax, increases
pleural pressure= increases alveolar pressure, air flows FROM lungs until alveolar
presure=atmospheric pressure
3. Active Exhalation: rest expiration is passive, inside pressure < outside pressure
(compressed lungs), pressure gradient generating air flow is the recoil pressure of lungs
QUESTIONS & ANSWERS
External Respiration Steps - Correct Answers -1. Ventilation
2. exchange of O2 and CO2 between air and blood
3. Transport of O2 and CO2.
4. Exchange of O2 and CO2 between blood and tissue.
Upper Tract - Correct Answers -Nose --> nasal cavity --> pharynx --> larynx
Lower tract - Correct Answers -trachea --> main bronchus -->bronchus -->bronchiole -->
terminal bronchiole -->Respiratory bronchiole -->alveolar duct --> alveolar wall
muscles of inspiration - Correct Answers -diaphragm, external intercostal muscles
muscles of expiration - Correct Answers -internal intercostal muscles , abdominal
muscles
pleural space - Correct Answers -between 2 membranes, lung covered by this, pleural
fluid fills it, allows membranes to rub against each other without causing friction
Respiration- 2 Processes - Correct Answers -1. Generating pressure gradient to move
air through airways
2. ability of O2 and CO2 to diffuse across alveolar-capillary barrier (pressure in alveoli
must be less then pressure in nose for air to flow down to alveoli)
VC - Correct Answers -vital capacity: max volume of air that can be expelled during
single breath following maximal inspiration (4500mL= IRV+ Vt+ERV)
TLC - Correct Answers -total lung capacity: max volume of air lungs can hold (5700mL=
VC+RV)
FEV1 - Correct Answers -forced expiratory volume in one second: derived only from 1st
second of expiratory effort. Normally expressed as ratio (FEV1/FVC), converted to %
Respiration Formula - Correct Answers -delta Pressure/ resistance = flow (diffussion)
Atmospheric Pressure (Pa) - Correct Answers -760mmHg at sea level, 0 remains
contast throughout body, decreases are altitude gained
, Alveolar Pressure (PA) - Correct Answers -pressure in alveoli, at end of inspiration,
alveolar pressure is the same as atmospheric pressure
Pleural Pressure (Ppl) - Correct Answers -pressure in pleural space, negative to
atmospheric pressure (because lungs want to collapse, yet chest wall wants to expand)
Transpulmonary Pressure (Ptp) - Correct Answers -Difference between alveolar
pressure and plerual pressure, also known as lung recoil pressure
Elastic Recoil in Lungs- 2 methods - Correct Answers -1. Elastin fibres: connective
tissue of lungs contain these, inhalation causes lungs to stretch, elastic recoil causes
lungs to contract
2. Surface tension- 70% of recoil properties, liquid layer resists forces, water molecules
are strong and resist being pulled apart
Alveolar Stability - 2 methods - Correct Answers -1. Pulmonary Surfactant- type 2
alveolar cells secrete lipids, dispersing water, reducing attraction, increased compliance
= decreased surface tension
2. Alveolar Interdependence- alveolus collapses , surrounding alveoli are stretched,
when they recoil, they pull outward on collapsed alveolus
Law of LaPlace - Correct Answers -2T (Surface tension)/ r (alveolar radius)= P
(collapsing pressure)
Alveolar Pressure Equation - Correct Answers -Alveolar Pressure (PA)- Pleural
Pressure (Ppl)= Lung Recoild Pressure (Pl)
Inflation and Exhalation - Correct Answers -- result of change in pleural and alevolar
pressure
1. Before inspiration= no flow, alveolar pressure= atmospheric pressure
2. During inspiration= pressure gradient established from atmosphere to alveoli
3. Ending inspiration= inspiratory muscle contraction decreases, elastic recoil pressure=
pleural pressure
4. EXPIRATION STARTS WHEN INSPIRATORY MUSCLES STOP CONTRACTING
Process of Inhalation and Exhalation (3 Steps) - Correct Answers -1. Onset of
Inhalation: alveolar pressure=atmospheric pressure, contraction causes decreased
pleural pressure, enlarges thoracic cavity, air flows down pressure gradient INTO lungs,
continues until alveolar pressure= atmospheric pressure again
2. Onset of Exhalation: end of inspiration when inspiratory muscles relax, increases
pleural pressure= increases alveolar pressure, air flows FROM lungs until alveolar
presure=atmospheric pressure
3. Active Exhalation: rest expiration is passive, inside pressure < outside pressure
(compressed lungs), pressure gradient generating air flow is the recoil pressure of lungs
