1. Respiratory Systems

2. Types of Respiration
External
Internal

3. Is the volume of air that you breath in equal to the volume of air that you breath out?
No. Typically, you burn more O2 than you release CO2 so more oxygen goes into your body than CO2 comes out. This ratio is typically 8 CO2 out for every 10 O2 in.

4. Respiratory Quotient (Carbon dioxide Production / Oxygen Consumption)
Carbohydrates 1.0
Proteins 0.8
Fats 0.7
AVERAGE 0.8

5. 4 Steps to Movement of Oxygen
Ventilation BULK
Lung Diffusion DIFFUSION
Blood Transport BULK
Tissue Diffusion DIFFUSION

6. 1. Ventilation 2. Gas 3. Circulation 4. Cellular exchange respiration
Figure 44-1
1. Ventilation
2. Gas
exchange
3. Circulation
4. Cellular
respiration
Environment
Ventilatory surface
Blood
Mitochondria
Respiratory system
Circulatory system

7. pressure of gas on either side of barrier to diffusion
Figure 44-5
Diffusion constant
(depends on
solubility of gas
and temperature)
Difference in partial
pressure of gas on either
side of barrier to diffusion
Area for
gas exchange
Distance
(thickness of
barrier to diffusion)

8. Partial Pressures % Gasses in Air Partial Pressure of Gases in air
79% “Nitrogen” (78.09% nitrogen; 0.93% argon)
20.95% Oxygen
0.038% Carbon Dioxide
Partial Pressure of Gases in air
Nitrogen * mmHg = 600 mmHg
Oxygen * 760 mmHg = 159 mmHg
CO * 760 mmHg = 0.29 mmHg

10. Partial Pressures in Air and in Water

11. pressure of gas on either side of barrier to diffusion
Figure 44-5
Diffusion constant
(depends on
solubility of gas
and temperature)
Difference in partial
pressure of gas on either
side of barrier to diffusion
Area for
gas exchange
Distance
(thickness of
barrier to diffusion)

12. Movement of O2 and CO2 is always “downhill”
Oxygen and Carbon Dioxide dissolve into the body fluid
O2 and CO2 are freely permeable to cell membranes
They can not be pumped or transported against a concentration gradient
They can be taken out of solution or converted to other chemicals for storage.
However, movement is always downhill

13. Mammalian Respiratory System

14. Breathing Air vs. Breathing Water
Water Air Ratio:water/air
O2 Concentration :30
(liter/liter)
Density (kg/liter) :1
Liters of medium :1
per liter O2
Kilograms medium ,000:1

15. Variations in O2, CO2, and pH in a tidal rock pool

16. Stagnant water can have a very
low oxygen partial pressure

17. Fish Respiratory System

18. Countercurrent flow Co-current flow Water flow over lamellae
Figure 44-8
Countercurrent flow
(seen in fish gills)
Co-current flow
(not seen in fish gills)
Water flow over lamellae
(% oxygen)
Water flow over lamellae
(% oxygen)
100%
70%
40%
15%
100%
90%
70%
50% O2
Diffusion
stops O2
90%
60%
30% 5% 0%
10%
30%
50%
Blood flow through lamellae
(% oxygen)
Blood flow through lamellae
(% oxygen)

19. Insect Respiratory System

20. Breathing through the anus

21. Breathing through Skin alone (large animal)

22. Pulmonary circulation
Figure 44-26
Tissues
PO2 40 mm Hg
PCO2 45 mm Hg
Blood leaving
tissue capillaries
PO2 40 mm Hg
PCO2 45 mm Hg
Blood entering
tissue capillaries
PO2 140 mm Hg
PCO2 40 mm Hg
Systemic
circulation
Inhaled air
PO2 160 mm Hg
PCO2 0.3 mm Hg
Exhaled air
PO2 120 mm Hg
PCO2 27 mm Hg
Pulmonary
artery
Pulmonary
vein
Aorta
Pulmonary circulation
Venae
cavae
Blood entering
alveolar capillaries
PO2 40 mm Hg
PCO2 45 mm Hg
Blood leaving
alveolar capillaries
PO2 104 mm Hg
PCO2 40 mm Hg
Alveoli of lungs
PO2 104 mm Hg
PCO2 40 mm Hg

23. PO2 & PCO2 Atmospheric CO2 = 397 ppm
(March 2013 Mauna Loa Observatory)
397 ppm = (divide by 1,000,000)
Percent = %
Partial Pres. = 0.3 mmHg
(760mmHg x )

24. Gas Exchange in Lung
PO2
&
PCO2

25. O2 Transport in Blood 1 Liter of blood contains 200 ml Oxygen
(assuming normal levels of Hemoglobin)
Dissolved in plasma - 1.5% (3 ml O2)
Bound to Hemoglobin % (197 ml O2)

26. Oxyhemoglobin Dissociation Curve
200
150
ml O2
L blood
100 50

28. Figure 44-18
Bohr Shift-Decreased binding of O2 to hemoglobin with
-increased temperature
-increased CO2
-decreased pH
pH 7.4
pH 7.2
% O2 unloaded
% O2 unloaded
Bohr shift

29. Figure 44-19
Fetal
hemoglobin
Adult (maternal)
hemoglobin

30. CO2 Transport in the Blood
Dissolved in plasma 10%
Bound to Hemoglobin 30%
Converted to bicarbonate 60%
CO2 + H2O <-> H2CO3 <-> HCO3- + H+

31. CO2 Transport: 1)Dissolved, 2)Bound to Hb 3)Bicarbonate
CO2 Transport: 1)Dissolved, 2)Bound to Hb 3)Bicarbonate *Note that CO2 has a big impact on pH.

32. Fick Principle of O2 transport
O2 delivery = C.O. * ([O2] a – [O2] v)