1. 14 November 2012 Respiratory Physiology
Lab this week: EKGs and Blood Pressure. Bring calculator and textbook to lab.
Wear clothes and shoes you can run in comfortably.
Work on Hemorrhage Diagram!

2. 1QQ 27 for 8:30
Beginning with a loss of 1 liter of blood, diagram the sequence of events that leads to a change in the frequency of action potentials in baroreceptors. (No abbreviations allowed.)

3. 1QQ 27 for 9:30
Beginning with a loss of 1 liter of blood, diagram the sequence of events that leads to a change in the frequency of action potentials in baroreceptors. (No abbreviations allowed.)

4. Respiration is the overall movement of gases between the outside environment and the internal cells.
Ventilation is the movement of air in and out of the lungs.
Ventilation should be matched to metabolism. O2
CO2
CO2 O2
Carbon Dioxide reacts with water!
CO2 + H20 ↔ H2CO3 ↔ H+ + HCO3-
Carbonic Acid Bicarbonate
So disturbances in gas exchange or ventilation are often associated with disruptions of pH.
pH changes with
Hypoventilation &
Hyperventilation

5. Gas Laws Dalton’s Law Total pressure = sum of partial pressures
PATM = P N2 + P O2 + P CO2
100% = 79% + 21% + <1%
P O2 = 0.21 x 760mmHg = 160
Partial pressure of Oxygen in atmosphere at sea level is 160 mmHg
Regardless of elevation, air is always 21% O2.
N2 is physiologically inert; ignore except for decompression sickness
Henry’s Law
Gases dissolve in liquids in proportion to their partial pressure in the air in contact with that liquid
air
P O2 =160 mmHg
liquid
P O2 =160 mmHg

6. Why the difference in partial pressures in Air and Alveoli?
Ventilation by Bulk Flow
Gas exchange by Diffusion
Where should the receptors be for the negative feedback loop for homeostasis?
Gas exchange
Gradient for CO2 is only 6 mmHg;
CO2 is more soluble and permeable than O2

7. Gas exchange All gases move by diffusion. Thus limited by:
Surface area
Distance
Concentration (partial pressure) gradient
In the lung, gases must move from air to water and vice versa. The amount is proportional to
Solubility (CO2 more soluble than O2)
Temperature (colder fluids dissolve more gas)
Pressure gradient

9. Respiratory Physiology
The physics of air flow
Flow in tubes
2) Ventilation
Poiseulle’s equation

10. Bronchitis= infection/inflammation of conducting airways
The Structure underlying the function:
Upper
Respiratory
Tract
Lower
Respiratory
Tract
Intercostal muscles
Bronchitis= infection/inflammation of conducting airways
Asthma = smooth muscles contract →increase resistance to airflow in conducting airways.

11. Greg R. and the story of spontaneous pneumothorax
Pneumothorax (unilateral due to each lung having its own compartment.
Visceral pleura and parietal pleura separated by fluid-filled pleural cavity which allows lung and chest wall to slide relative to each other but remain adhered unless air enters the pleural cavity (which leads to collapse of the lung and outward expansion of chest wall on that side.)
Greg R. and the story of spontaneous pneumothorax

12. Sleep Apnea a)obstructive, b)central
Upper Tract
Sleep Apnea a)obstructive, b)central
&
CPAP

13. Continuous Positive Airway Pressure