1. The Respiratory System
Chapter 23, part 4
The Respiratory System

2. SECTION 23-9 Gas Pickup and Delivery

3. Blood in peripheral capillaries delivers O2 and absorbs CO2
Reactions are completely reversible

4. Figure 23.20 An Overview of Respiratory Processes and Partial Pressures in Respiration
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Animation: Respiratory Processes and Partial Pressures in Respiration
Figure 23.20a, b

5. Oxygen transport Carried mainly by RBCs, bound to hemoglobin
The amount of oxygen hemoglobin can carried is dependent upon:
PO2 pH
temperature
BPG
Fetal hemoglobin has a higher O2 affinity than adult hemoglobin

6. Figure 23.21 The Oxygen-Hemoglobin Saturation Curve

7. Figure 23.21 The Oxygen-Hemoglobin Saturation Curve

8. Figure 23.22 The Effect of pH and Temperature on Hemoglobin Saturation
Figure 23.22a, b

9. Figure 23.23 A Functional Comparison of Fetal and Adult Hemoglobin

10. Carbon dioxide transport
7% dissolved in plasma
70% carried as carbonic acid
buffer system
23% bound to hemoglobin
carbaminohemoglobin
Plasma transport

11. Figure 23.24 Carbon Dioxide Transport in Blood

12. Figure 23.24 Carbon Dioxide Transport in Blood

13. Summary of gas transport
Driven by differences in partial pressure
Oxygen enters blood at lungs and leaves at tissues
Carbon dioxide enters at tissues and leaves at lungs
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Animation: Gas Exchange and Gas Transport

14. Figure 23.25 A Summary of the Primary Gas Transport Mechanisms
Figure 23.25a, b

15. SECTION 23-10 Control of Respiration

16. Gas absorption/generation balanced by capillary rates of delivery/removal
Homeostatic mechanisms maintain balance
Local regulation of gas transport and alveolar function include
Lung perfusion
Alveolar capillaries constrict in low oxygen
Alveolar ventilation
Bronchioles dilate in high carbon dioxide

17. Respiratory centers of the brain
Medullary centers
Respiratory rhythmicity centers set pace
Pons
Apneustic and pneumotaxic centers

18. Figure 23.27 Respiratory Centers and Reflex Controls

19. Respiratory reflexes
Respiratory centers are modified by sensory information including
Chemoreceptor reflexes
Level of carbon dioxide
Baroreceptors reflexes
Hering-Breuer reflexes
Prevents overinflation
Protective reflexes

20. Figure 23.28 The Chemoreceptor Response to Changes in PCO2

21. Voluntary control of respiration
Regulation of respiratory rate is dependent upon:
Conscious and unconscious thought
Emotional state
Anticipation
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Animation: Control of Respiration

22. SECTION 23-11 Changes in the Respiratory System at Birth

23. Neonatal Respiration Upon taking the first breath:
Inhaled air enters the respiratory passages for the first time
The bronchial tree and most of the alveoli are inflated
Subsequent breaths complete inflation of the alveoli

24. SECTION 23-12 Aging and the Respiratory System

25. The efficiency of the respiratory system decreases with age as:
Elastic tissue deteriorates causing lower lung compliance and vital capacity
Chest movements are restricted by arthritic changes
Some degree of emphysema normally occurs

26. You should now be familiar with:
The primary functions of the respiratory system
The organs of the respiratory system and their functions
The processes of external and internal respiration
The physical principles governing the movement of air into the lungs and the diffusion of gases into the blood
The important structural features of the respiratory membrane
How oxygen and carbon dioxide are picked up, transported and released in the blood