1. Respiration Physiology

2. External Respiration vs. Internal Respiration
exchange of O2/CO2 btwn. fluids & environment (organ level) vs. btwn cells (cellular level)

3. Four major Steps of Respiration
1. Pulmonary Ventilation (breathing)  air into & out of lungs
2. Gas Diffusion Across Respiratory Membrane  from alveolar to alveolar capillaries
3. Storage and Transport of O2/ CO2  from alveolar caps to caps in tissues
4. Exchange of O2/ CO2 btwn blood and tissues

4. The last two will be referred to as Gas pickup & delivery.
If any of these steps is affected  hypoxia occurs ( tissues are starved of O2)
If O2 is completely shut off  anoxia

5. Hypoxia

6. Boyle’s Law-

7. Pulmonary Ventilation  air into and out of aveoli (continual supply of O2 prevents build up of CO2)
Boyle’s Law  inverse relationship btwn volume & pressure of a gas. As one increases, the other decreases.
Inhalation/expiration changes the size of the lungs which changes the pressure

8. Pressure gradients move air into & out from hi to low
Pleural cavity / fluid slide easily side to side but creates a suction when you try to separate
Ex. wet glass on table
Surface of each lung sticks to wall of chest and top of diaphragm

9. This fluid bond is actually what keeps lungs inflated!
Vol. of thoracic cavity changes when diaphragm or ribs move
When diaphragm is relaxed, it curves upward in a dome shape, when it contracts, it moves downward and increases the volume of cavity.
Pg. 453 Fig. 16.2

10. Inhalation = ribs elevate, diaphragm contracts, size of cage increases, pressure decreases & air goes into the lungs.
The opposite occurs upon Exhalation = rib cage gets smaller, volume decrease, pressure increases, & air moves out of lungs.

11. Respiratory Cycle = 1 single inhalation & exhalation
Tidal volume = amt. of air into & out of lungs in a single respiration; avg. 500ml
--- but only 350 ml. enters aveoli; the other 150 ml. keep alveoli inflated.
Collapsed lung = when pleural fluid bond is broken

12. Respiratory Muscles
internal and external intercostals ( ribs)  % of work
diaphragm 
75 % of work

13. Mouth to mouth  after each breath, contact is broken to permit passive exhalation, meets temporary O2 demands of cells.
CPR  cardiopulmonary resusitation
Pregnant women rely on costal breathing b/c diaphragm can’t move a lot

14. Respiration rate = # of breaths per minute; avg. adult = 12-18
Air in alveoli always contains less O2 and more CO2 than outside air. This ensures that O2 is constantly flowing INTO the aveoli.

15. Respiratory volumes
Resting tidal volume = amt. of air into/out of lungs during a quiet resp. cycle
Expiratory Reserve Vol. = amt. of air that COULD BE voluntarily expelled; 1000ml!
Residual vol. = amt. left after maximum exhalation

16. Inspiratory Reserve Vol. = amt
Inspiratory Reserve Vol. = amt. that can be taken in over & above the tidal vol.
Total Lung capacity = ( ER + TV + IR) + RV; 6 L in males; 4.2 L in females
Spirometer = used to measure lung volumes
Wheezing = air whistling thru. constricted airways

17. Henry’s Law

18. Gas exchange @ Resp. Membrane
Henry’s Law = gas molecules go from liquid into air easily
ex. open can of soda
Decompression sickness = decrease in pressure causes N2 to come out of soln. & collect in joints; ex scuba divers
Diffusion is efficient b/c
-Difference in partial pressures is great
- the greater the gradient, the faster the diffusion
- if the pressure of O2 decreases, that the diffusion into the blood decreases which makes people light altitudes of 3000m or more.
Fig pg. 462 As blood goes from heart to lungs, there is more CO2 than O2; picks up O2 and drops off CO2
Goes to heart to get pumped systemically
Goes to cells where O2 is low and CO2 is high; both are exchanged

19. BOHR Shift O2 transport Hb saturation1 heme can hold 4 O2
normally, heme is 50% saturated; only holds 2

20. Gas Pickup and Delivery
CO poisioning  CO
competes with O2 for binding sites; CO usually wins b/c it has a higher affinity (liking) for Hb
* treatments = breathe pure O2 or transfuse RBC’s

21. Hb/pH  THE BOHR SHIFT pg. 463
when pH drops to 7.2, Hb molecules change shape and release O2 (lose affinity)
CO2 combines with the water in the blood to make carbonic acid
H+ ionizes and lowers the pH

22. Hb and temp. as temp. increases, Hb releases more O2, and vice versa;
ensures that skeletal muscles generating heat get the O2 they need

23. Fetal Hb has a much higher affinity for O2 than adult Hb; ensures that fetus gets O2 across placenta
CO2 transport  opposite reaction of BOHR SHIFT occurs; as pH increases, heme gains affinity for O2