1. RESPIRATORY SYSTEM EXCHANGE OF GASES
PowerPoint® Lecture Slide Presentation by Robert J. Sullivan, Marist College
RESPIRATORY SYSTEM
EXCHANGE OF GASES
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.

2. What is Human Respiration?
The human respiratory system allows one to obtain oxygen, eliminate carbon dioxide.
Breathing consists of two phases, inspiration and expiration
Inspiration- the process of taking in air
Expiration- the process of blowing out air

3. Human Respiratory System
Figure 10.1

4. Organs in the Respiratory System
STRUCTURE
FUNCTION
nose / nasal cavity
 warms, moistens, & filters air as it is inhaled
pharynx (throat)
 passageway for air, leads to trachea
larynx
 the voice box, where vocal chords are located
trachea (windpipe)
 keeps the windpipe "open"  trachea is lined with fine hairs called cilia which filter air before it reaches the lungs
bronchi
 two branches at the end of the trachea, each lead to a lung
bronchioles
 a network of smaller branches leading from the bronchi into the lung tissue & ultimately to air sacs
alveoli
 the functional respiratory units in the lung where gases are exchanged

5. Components of the Upper Respiratory Tract
Figure 10.2

6. Upper Respiratory Tract Functions
Passageway for respiration
Receptors for smell
Filters incoming air to filter larger foreign material
Moistens and warms incoming air
Resonating chambers for voice

7. Components of the Lower Respiratory Tract
Figure 10.3

8. Lower Respiratory Tract
Functions:
Larynx: maintains an open airway, routes food and air appropriately, assists in sound production
Trachea: transports air to and from lungs
Bronchi: branch into lungs
Lungs: transport air to alveoli for gas exchange

9. Gas Exchange Between the Blood and Alveoli
Figure 10.8A

10. Respiratory Cycle
Figure 10.9

11. Breathing Regulation Involuntary
Have Chemoreceptors in walls of arteries that detect CO2 levels
High CO2 levels in blood detected and send message to respiratory center of brain (Medulla)
Medulla send message to diaphragm and rib muscles to increase rate and depth of breath
Low pH of blood also stimulates medulla

12. External vs. Internal Respiration
Gas exchange in alveoli with capillaries
Internal
Gas exchange in capillaries with body cells

13. Oxygen transport
In lungs oxygen combines with Hemoglobin to form oxyhemoglobin

14. Structure of hemoglobin

15. Oxygen Transport Oxygen released in locations of low O2 concentration
Carbon monoxide has greater binding ability to hemoglobin than oxygen

16. Carbon Dioxide Transport
70% as Bicarbonate in plasma
CO2 + H20  H2CO3  H++ HCO3-
carbonic bicarbonate
acid
Carbonic Acid Buffering system

17. Carbon Dioxide Transport
20% as carbaminohemoglobin
CO Hb HbCO2
(HbCO is carboxyhemoglobin)

18. Carbon Dioxide Transport
10% as free CO2 in plasma

19. Carbon Dioxide Transport

20. Video 1
video 2

22. Respiratory volumes
tidal volume: air inhaled or exhaled in one quiet breath
inspiratory reserve volume: air in excess of tidal inspiration that can be inhaled with maximum effort
expiratory reserve volume: air in excess of tidal expiration that can be exhaled with maximum effort
residual volume: air remaining in lungs after maximum expiration, keeps alveoli inflated

23. Measurement of Lung Capacity
Figure 10.10A

24. Malfunctions & Diseases of the Respiratory System
asthma
severe allergic reaction characterized by the constriction of bronchioles
 bronchitis
inflammation of the lining of the bronchioles
emphysema
condition in which the alveoli deteriorate, causing the lungs to lose their elasticity
pneumonia
condition in which the alveoli become filled with fluid, preventing the exchange of gases
lung cancer
irregular & uncontrolled growth of tumors in the lung tissue

25. Four Respiration Processes
Breathing (ventilation): air in to and out of lungs
External respiration: gas exchange between air and blood
Internal respiration: gas exchange between blood and tissues
Cellular respiration: oxygen use to produce ATP, carbon dioxide as waste

26. Perfusion and Ventilation

27. Oxygen Dissociation Curve
Click on the numbered sections on the graph for an explanation of what happens at each stage
Oxygen Dissociation Curve
Saturation of Haemoglobin / %
Partial Pressure of Oxygen/ kPa 2 4 6 8 10 12 20 40 60 80
100 5 4 3
The red blood cells transport the oxygen to respiring tissues. The partial pressure of oxygen in these tissues is low, as the oxygen is being used for respiration.
Under conditions of a lack of oxygen (low partial pressure of oxygen), the haemoglobin yields its oxygen to the respiring cells – we refer to this as dissociation.
Haemoglobin’s properties allow it to bind with a lot of oxygen at a high partial pressure of oxygen, but at low partial pressure, only a limited amount binds to it.
The partial pressure of oxygen is high and the haemoglobin reaches saturation.
The red blood cells collect oxygen in the capillaries surrounding the lungs.
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