1. Pulmonary Systems
Chapter 9 in text

2. Mid session Available 21/8/07 – 28/8/07 Practice test now available
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“Mid session quiz”
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30 minute time limit

3. Pulmonary Systems Review
Structure
Function

5. Pulmonary Structure and Function
The ventilatory system
Supplies oxygen required in metabolism
Eliminates carbon dioxide produced in metabolism
Regulates hydrogen ion concentration [H+] to maintain acid-base balance
3 main functions
GAS EXCHANGE ANIMATION

6. Mechanics of Breathing

7. Breathing
At rest
Air in  Trachea- humidified and brought to body temperature
 divides into 2 branches lungs
Lungs hold 4-6 litres of ambient air- huge surface area
300 million alveoli
250 ml oxygen in and 200 ml Carbon dioxide out each minute
Main idea of the lungs is that they are a very compact and convenient area for gas exchange
Probably read in the text that, although lungs weigh only about 1 kg, if spread out, would cover the same area as ½ a tennis court, or 1 whole badminton court
Alveoli
Where all the action happens!! Latin for “little cavity”
Alveoli is completely intertwined with capillaries; and the walls of the alveoli and the cappilaries are both thin enough to allow oxygen and carbon dioxide to travel through the walls

8. Diaphragm contracts (flattens) Moves downward (10cm) Thoracic volume
Inspiration
Ribs rise
Diaphragm contracts (flattens)
Moves downward (10cm)
Thoracic volume
Air in lungs expands
Pressure
to 5 mm Hg below atmospheric pressure
Difference between outside air and lungs = air is sucked in until pressure inside and out is the same
Lungs do not contain muscle that contracts them (Like the heart)
Instead, diaphragm controls thoracic volume and subsequent pressure.
Ribs rise due to contraction of intercostal muscles

9. Expiration Ribs move back down Diaphragm relaxes (rises)
Thoracic volume
Pressure
Difference between outside air and lungs = air is pushed out until pressure inside and out is the same
Ribs move down due to relaxation intercostal muscles (breathing at rest)
Feel that pressure increase when you are swimming underwater, holding breath
Expiration during exercise is far more forceful due to the actions of the intercostal and abdominal muscles  more forceful expiration to eliminate Co2  also increased differences in pressure that results in increased oxygen being drawn in.
What do you notice about the arrows on both of these pages??
Up down up down or down up down up
Can simplify and say that when diaphragm goes down, air goes in and when diapraghm goes up, air goes out

11. Lung Volumes

12. Lung Volumes Static lung volume tests Dynamic lung volume tests
Evaluate the dimensional component for air movement within the pulmonary tract, and impose no time limitation on the subject
Dynamic lung volume tests
Evaluate the power component of pulmonary performance during different phases of the ventilatory excursion
Static= space available
Dynamic = power / force behind expiration

13. Spirometry
Static and Dynamic lung volumes are measured using a spirometer

14. Static Lung Volumes TV- breath normally- this is your tidal volume
IRV- breath normally, breath out normally, then breath in as much as you can. This is inspiratory reserve- it is the max capacity for air in the lungs. Can be 2-3 litres
Breath normally
ERV- Breath in normally, then breath out as much as you can – average one litre of air
FVC (Forced vital capacity) = maximum you can force in and out of lungs IRV + ERV
RLV- residual- the lungs are never empty- RLV is the amount left in them after forced expiration. Usually one litre\
TLC- Total lung capacity = amount you can force in/ out + residual volume left- TLC = IRV + ERV + RLV

15. Dynamic lung volumes Depend on Volume of air moved and the
Speed of air movement
FEV/FVC ratio
MVV
Remember dynamic is looking at the power behind what you can breath

16. FEV/FVC Ratio Forced Expiratory Volume Forced Vital Capacity
Ratio tells us the speed at which air can be forced out of lungs
Normal = 85% FVC can be expired in 1 second.
FVC= max amount expired after maximal inspiration
Ususally used in the diagnosis of obstructive lung diseases such as emphysema, asthma etc

17. Maximal Voluntary Ventilation
Breath as hard and fast as you can for 15 seconds
Multiply by 4
And you have Maximal Voluntary Ventilation
MVV-
Males: Litres
Females: Litres
Elite athletes up to 240 Litres

18. Minute Ventilation At Rest 12 breaths per minute
Tidal volume = 0.5L per breath
= 6 Litres of air breathed p/min
During Exercise
50 breaths p/ minute
Tidal Volume = 2 L per breath
= 100L p/min

19. Alveolar Ventilation Minute ventilation is just total amount of air
Alveolar ventilation refers to the portion of minute ventilation that mixes with the air in the alveolar chambers
Minute ventilation minus anatomical dead space ( ml)- the air that is in the trachea, bronchi etc
Anatomical dead space = air that isn’t in alveoli and is therefore no good at all as is not involved with gas exchange in the blood

20. Alveolar Ventilation =
Minute ventilation (TV x breathing rate) – dead space

21. Gas exchange

22. Gas Exchange in the Body
The exchange of gases between the lungs and blood, and their movement at the tissue level, takes place passively by diffusion

24. Oxygen Transport in the Blood
Blood transports oxygen in 2 ways:
In physical solution — Dissolved in the fluid portion of the blood
Combined with hemoglobin — In loose combination with the iron-protein hemoglobin molecule in the red blood cell

25. CO2 Transport in Blood In physical solution As carbamino compounds
(~7%) dissolved in the fluid portion of the blood
As carbamino compounds
(~20%) in loose combination with amino acid molecules of blood proteins
As bicarbonate
(~73%) combines with water to form carbonic acid

26. Regulation of Pulmonary Ventilation

27. Temp- increse in body temp directly stimulates neurons to fire to tell the diaphragm and intercostal muscles to act

28. Regulation at rest: Plasma Pco2 and H+ Concentration
The partial pressure of CO2 provides the most potent respiratory stimulus at rest
[H+] in the cerebrospinal fluid bathing the central chemoreceptors provides a secondary stimulus driving inspiration
If you hold your breath, the thing that forces you to breath again is the high Co2

29. Ventilatory Regulation During Exercise
Chemical control
Po2
Pco2
[H+]
Nonchemical control
Neurogenic factors
Cortical influence
Peripheral influence
During exercise
Remember oxygen debt and deficit?
Start exercise- rapid increase in breaathing rate- 1st 20 seconds = plateau
Stop exercise- fairly rapid slowing down, but remains at 40% of what was happening during exercise
Think about what happened in lactate threshold test
Chemical- levels of these three prompt action Co2 is by product of atp production; Hydrogen is produced in glycolysis  Kreb’s cycle
Nonchemical-
Neural control- brain tells the neurons to tell the diaphragm and intercostals to relax/ contract  inflate
Cortical- anticipatory effect
Peripheral- respiration increases because the joints/muscles are moving  receptors

30. Ventilation in steady rate exercise
Of oxygen ( V E/ V O2)
Quantity of air breathed per amount of oxygen consumed
Remains relatively constant during steady-rate exercise- 25 L air breathed per 1L o2 consumed at 55% Vo2 max
Of carbon dioxide ( V E/ V CO2)
Remains relatively constant during steady-rate exercise

31. Ventilatory Threshold
The point at which pulmonary ventilation increases disproportionately with oxygen uptake during graded exercise
The excess ventilation relates to the increased CO2 production associated with buffering of lactic acid
Another threshold!

32. Have to increase ventilation to increase amount of oxygen to enable aerobic respiration

33. Pulmonary adaptations to Exercise
Chapter 13

34. Goals of aerobic training

35. Adaptations to Maximal exercise Minute ventilation increases
Increased oxygen uptake
Pulmonary adaptations often some of the first to be noticed basically reduced feeling of breathlessness in untrained
20 weeks of training increased pulmonary muscle strength by 16%  intercostals and diaphragm better able to create pressure differences which result in inspiration/ expiration

36. Submaximal Exercise Ventilatory equivalent for oxygen
Ventilatory muscles stronger
Ventilatory equivalent for oxygen
( V E/ V O2) reduces indicates breathing efficiency
This leads to
Reduced fatigue in ventilatory muscles
O2 that would have been used by those muscles can be used by skeletal muscle.
Ventlatory equivalent for oxygen is the ratio of the amount of air breathed to the amount of oxygen obtained

37. Pulmonary Adaptations
Increased tidal volume
Decreased breathing frequency
Increased time between breaths (Increased time for oxygen to get into bloodstream)
Therefore less oxygen in exhaled air