Pulmonary respiration refers to breathing and the exchange of gases in the lungs. During exercise, pulmonary respiration plays a key role in maintaining blood-gas homeostasis by increasing ventilation, gas exchange, and blood flow to the lungs. The conducting zone transports air to the respiratory zone, where gas exchange occurs in alveoli within the lungs.

1. Respiration During Exercise

2. • Respiratory physiology can be divided
into two separate but related subdivisions:
(I) Pulmonary respiration and
(2) Cellular respiration.

4. Pulmonary Respiration
• Pulmonary respiration refers to
ventilation (breathing) and the exchange
of gases (02 and CO2) in the lungs

5. • BLOOD-GAS homeostasis (ie, O2 and
CO2 tensions) during exercise,
• WHICH TYPE OF RESPIRATION ???

6. Cellular Respiration
Cellular respiration relates to O2 utilization
and CO, production by the tissues

7. PULMONARY RESPIRATION
Because
The pulmonary respiratory system
plays a key role in maintaining
blood-gas homeostasis

8. FUNCTIONS OF THE LUNG????

9. STRUCTURE OF THE RESPIRATORY
SYSTEM

10. • The air passages of the respiratory system
are divided into two functional zones:
(I) The conducting zone and
(2) The respiratory zone

11. •Conducting Zone includes all
those anatomical structures
(e.g., trachea, bronchial tree,
bronchioles) that
air passes through to reach the
respiratory zone.
The region of the lung where
gas exchange occurs is labeled
the Respiratory Zone and
includes the respiratory
bronchioles and alveolar sacs.

12. Conducting Zone
• The conducting zone of the respiratory system not only
serves as a passageway for air, but also functions to
humidify and filter the air as it moves toward the
respiratory zone of the lung.
• This warming and humidification of air serves to protect
body temperature and prevents the delicate lung tissue
from desiccation (drying out)

13. Respiratory Zone
• Gas exchange in the lungs occurs across about 300
million tiny (025-050 mm diameter) alveoli.
• It is estimated that the total surface area available for
diffusion in the human lung is 60 to 80 square meters. or
about the size of a tennis court .
• Passages that filter air and transport it into the lungs
where gas exchange occurs within tiny air sacs called
alveoli.

15. MECHANICS OF BREATHING
• Thus, inspiration occurs due to the pressure in the
lungs (intrapulmonary) being reduced below
atmospheric pressure.
• Conversely, expiration occurs when the pressure
within the lungs exceeds atmospheric pressure.

16. • The diaphragm is the most important muscle
of inspiration and is the only skeletal muscle
considered essential for life.
• This thin, dome-shaped muscle inserts into
the lower ribs and is innervated by the
phrenic nerves.

17. • During normal quiet breathing the
diaphragm performs most of the work of
inspiration.
• However, during exercise, accessory
muscles of inspiration are called into
play.

18. These include the:
•External intercostal muscles,
•Pectoralis minor,
•The scalene muscles, and
•The sternocleidomastoids

19. • Expiration is passive during normal, quiet
breathing.
• That is, no muscular effort is necessary for
expiration to occur at rest.
• This is true because the lungs and chest walls are
elastic and tend to return to equilibrium
position after expanding during inspiration

20. PULMONARY VENTILATION
• Pulmonary ventilation refers to the movement of
gas into and out of the lungs.
• The amount of gas ventilated per minute is the
product of the frequency of breathing (f) and the
amount of gas moved per breath (tidal volume)
V” means volume per unit of time (generally one minute).

21. Ventilation During Exercise
Forced or labored inspiration and
expiration are active processes,
dependent on muscle actions.

22. PULMONARY VOLUMES
AND CAPACITIES
• Pulmonary volumes can be measured via a
technique known as Spirometry.
• Modern spirometers use computer technology to
measure pulmonary volumes and the rate of
expired airflow .

23. • vital capacity (Ve) :is defined as the maximum amount of
gas that can be expired after a maximum inspiration.
• Second , the residual volume (RV) is the volume of gas
remaining in the lungs after a maximum expiration.
• Finally, total lung capacity (TLC) is defined as the
amount of gas in the lungs after a maximum inspiration,
and is the sum of the two lung volumes (VC + RV).

26. DIFFUSION OF GASES
• Dalton's law, the total pressure of a gas
mixture is equal to the sum of the pressures
that each gas would exert independently.
• Gas moves across the blood-gas interface in
• the lung due to simple diffusion

27. Pulmonary Diffusion
• Process by which gases
are exchanged across
the respiratory
membrane in the
alveoli.

28. Pulmonary Diffusion
• Gases diffuse along a pressure gradient,
moving from an area of higher pressure to
one of lower pressure.
• Thus oxygen enters the blood and carbon
dioxide leaves it.

29. • Difference in partial pressure across the
blood-gas interface, CO2 leaves the blood
and diffuses into the alveolus, and O2
diffuses from the alveolus into the blood.
• Blood leaving the lung has a P02 of
approximately 95 mm Hg and a PC02 of 40
mm Hg

30. Oxygen Exchange
• Oxygen diffusion capacity increases as you
move from rest to exercise.
• When your body needs more oxygen, oxygen
exchange is facilitated.

31. BLOOD FLOW TO THE LUNG