Five Steps of Respiration - Kirkwood Community · PDF file ·...
1
Intrapulmonary pressure (Ppul) – pressure within the alveoli (759-761 mmHg) Atmospheric pressure (Patm) Pressure exerted by the air (760 mmHg) Intrapleural pressure (Pip) – pressure within the pleural cavity (755-757 mmHg) Basic Pressures Respiratory Volumes Two forces act to pull the lungs away from the thoracic wall. Elasticity of lungs causes them to assume smallest possible size Surface tension of alveolar fluid draws alveoli to their smallest possible size The lungs would collapse if these were the only forces. 759 mmHg 755 mmHg Ppul pressure is less than atm = Breathing In 761mmHg 757 mmHg Ppul pressure is greater than atm = Breathing Out Atm= 760mmHg • Pressure Disturbances: – Unable to expand lung • Scar tissue • Reduced surfactant • Mucous • Fluid – Unable to contract lung • Emphysema • Resistance Disorders Tumor: obstruction Asthma: constriction of air ways. Boyle’s Law Decreased volume = Increased pressure Increased volume = Decreased pressure Breathe Out Breathe In 760 761 760 759 • • • • If the volume of the lung is decreased… The pressure increases… The pressure in the lung is higher than atmosphere… Breathe out • If the volume of the lung is increased… • The pressure decreases… • The pressure in the lung is lower than atmosphere… • Breathe in emphysema asthma scar tissue mucous fluid in lungs surfactant Matching of alveolar ventilation and pulmonary blood perfusion Structural characteristics of the respiratory membrane Partial pressure gradients and gas solubilities • Blood gases in blood: – CO 2 >> O 2 >> N 2 N 2 O 2 CO 2 N 2 CO 2 O 2 Air Blood Henry’s and Dalton’s Laws Slower flow, more time to take in O2 We’re full of O2 so lets go Is only 0.5 to 1 m thick, allowing for efficient gas exchange (thin) Have a total surface area (in males) of about 60 m2 (40 times that of one’s skin) (much surface area) Basics are, respiratory membranes are thin with a lot of surface area. Both thickening (edema) or loss of area (emphysema) will significantly alter respiration. Normal Range Reserve O 2 O 2 O 2 O 2 O 2 O 2 O 2 O 2 O 2 O 2 Hemoglobin is almost completely saturated at a PO Further increases in PO small increases in oxygen binding Oxygen loading and delivery to tissue is adequate when PO levels Work ↑ Temp ↑ BPG ↑ acid Hb likes O 2 less O 2 is dropped off ↑ CO 2 Tissue is nourished and recovers from Haldane effect CO2 O2 7% dissolved in plasma 70% carried as carbonic acid buffer system 23% bound to hemoglobin carbaminohem oglobin 98.5 % bound to Hb 1.5 % Dissolved in plasma 1. Ventilation 5. Cellular Respiration 2. External Respiration 3. Oxygen/Carbon Dioxide Transport 4. Internal Respiration Five Steps of Respiration Lung Collapse Disturbances of Pressure and Resistance Pressures during Ventilation Control of Ventilation
Transcript of Five Steps of Respiration - Kirkwood Community · PDF file ·...
Intrapulmonarypressure (Ppul) – pressure within the alveoli(759-761 mmHg)
Atmospheric pressure (Patm)Pressure exerted by the air(760 mmHg)
Intrapleural pressure (Pip) – pressure within the pleural cavity(755-757 mmHg)
Basic Pressures
Respiratory Volumes
Two forces act to pull the lungs away from the thoracic wall.
Elasticity of lungs causes them to assume smallest possible size
Surface tension of alveolar �uid draws alveoli to their smallest possible size
The lungs would collapse if these were the only forces.
759 mmHg
755 mmHg
Ppul pressure is less than atm = Breathing In
761mmHg
757 mmHg
Ppul pressure is greater than atm = Breathing Out
Atm=760mmHg
• Pressure Disturbances:– Unable to
expand lung• Scar tissue• Reduced
surfactant• Mucous• Fluid
– Unable to contract lung• Emphysema
• Resistance Disorders
Tumor: obstructionAsthma: constriction of air ways.
Boyle’s Law
Decreased volume =Increased pressure
Increased volume =Decreased pressure
Breathe Out Breathe In
760
761
760
759
•
••
•
If the volume of the lung is decreased…The pressure increases…The pressure in the lung is higher than atmosphere…Breathe out
• If the volume of the lung is increased…•The pressure decreases…•The pressure in the lung is lower than atmosphere…•Breathe in
emphysema asthmascar tissuemucous�uid in lungs surfactant
Matching of alveolar ventilation and pulmonary blood perfusion Structural characteristics of
the respiratory membrane
Partial pressure gradients and gas solubilities
• Blood gases in blood:– CO2 >> O2 >> N2
N2 O2 CO2
N2 CO2O2
Air
Blood
Henry’s and Dalton’s LawsSlower flow, more time to take in O2
We’re full of O2 so lets go
Is only 0.5 to 1 �m thick, allowing for e�cient gas exchange (thin)
Have a total surface area (in males) of about 60 m2 (40 times that of one’s skin) (much surface area)
Basics are, respiratory membranes are thin with a lot of surface area. Both thickening (edema) or loss of area (emphysema) will signi�cantly alter respiration.
Norm
al Range
Reserve
2 of 70 mm Hg2 produce only
2 is below normal
O2O2
O2O2
O2
O2O2
O2O2
O2
Hemoglobin is almost completely saturated at a POFurther increases in POsmall increases in oxygen bindingOxygen loading and delivery to tissue is adequate when POlevels
Work
↑ Temp
↑ BPG
↑ acid
Hb likes O2 less
O2 is dropped off
↑ CO2
Tissue is nourished and recovers from
Haldane effect
CO2
O2
7% dissolved in plasma 70% carried as carbonic acidbu�er system23% bound to hemoglobin carbaminohemoglobin
98.5 % bound to Hb1.5 % Dissolved in plasma
1. Ventilation
5. Cellular Respiration
2. External Respiration
3. Oxygen/Carbon Dioxide Transport
4. Internal Respiration
Five Steps ofRespiration
Lung Collapse
Disturbances of Pressureand Resistance Pressures during Ventilation
Control of Ventilation
