Transcript The Oxygen Transport System

INTRODUCTION
The Oxygen Transport
System
I. Pulmonary Ventilation
Movement of Air in & out of the Lungs
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A. Minute Ventilation
.
V
The amount of Air ventilated by
the lungs in one Minute
.
VE
Volume Expired in One Minute
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Tidal Volume (TV)
The volume of Air ventilated per Breath
Frequency (f)
The Number of Breaths/minute
VE = TV x f
Minute ventilation =TV x f
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Ventilation during Exercise
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leveling
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Rapid
Decrease
Slower Rise
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Slower
Decrease
10
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Rapid Rise
ANT RISE 0
ANT RISE
REST
Exhaustion
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Ventilation as a Limit to
Performance
•Performance is not limited by ventilation
•Ventilation will INCREASE out of
proportion to workload so that
Ventilation becomes greater than NecessaryHYPERVENTILATION •excessive movement of air in & out caused by increased depth and
frequency of breathing and resulting in elimination of CO2
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II. Alveolar Ventilation
AIR (O2)
into lungs
Alveoli
blood
Tiny air sacs deep in lung which have contact with the
Pulmonary Capillaries to exchange gases
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II. Alveolar Ventilation
DEAD SPACE
those areas of the body that air enters but
does not go into the alveoli - hence -
NO GAS EXCHANGE
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Ventilation and Smoking
• Shortness of Breath
• Increased Airway Resistance
– Respiratory Muscles work Harder to
ventilate
- thus, these muscles require MORE
Oxygen
Results in LESS Oxygen for Skeletal
Muscles
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Ventilation and Smoking
•
Pulmonary Ventilation
•
Endurance
•
MAXIMUM Oxygen Consumption
VO2max = the max rate at which O2 can be
consumed per minute
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Second Wind
• Sudden transition of feeling distress or fatigue
early in prolonged exercise to a more
comfortable feeling later in exercise
• Possible Causes include:
– slow ventilatory adjustments brought on by the
breathlessness felt early’
– Removal of lactic acid built early from delayed
blood flow changes
– Relief from muscle fatigue
– Adequate Warm-up
– Psychological factors
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Stitch in Side
• Occurs early in prolonged exercise and
subsides as exercise continues
• Sharp Pain or “Stitch “ in side or rib
cage area
• May interfer w/ exercise- must stop
• Possible Causes include:
– HYPOXIA or lack of O2 in Resp
Muscles
– occurs more in Untrained athletes
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II. GAS EXCHANGE
Exchange of Oxygen & Carbon
Dioxide
between the Air and Blood
• TWO TYPES
– Alveolar Capillary Membrane
– Tissue Capillary Membrane
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Alveolar Capillary Membrane
Thin layer of tissue that separates air in Aleoli
from blood in Capillaries
1st EXCHANGE of O2 and CO2
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TissueCapillary
Capillary
Membrane
with RBC
Thin capillary membrane between blood and
tissues in body
2nd EXCHANGE of O2 and CO2
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GAS EXCHANGE by
DIFFUSION
Movement of gases from higher
concentrations to lower concentrations
Diffusion Gradient=
pp of gas in highest conc. Minus
the pp of gas in venous blood
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Partial Pressure
The pressure exerted by gas in relation to the % or
concentration of the gas within a volume
At sea Level- alveolar pO2 =100mmHbg = 100% sat Hbg
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Diffusion Gradients dependent on
Partial pressures (p) of gas in 2
different areas
Alveoli
pO2 HIGH
Alveoli
pCO2 LOW
Blood
pO2 LOW
Blood
pCO2 HIGH
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Diffusion Capacity in Athletes
• Alveolar- Capillary diffusion is greater
during max exercise in (endurance)
athletes than Nonathletes
• see Table 8.5
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NEW SECTION
Transport of Gases by the
Blood
O2 and CO2 are carried in the blood by:
1.Chemical CombinationOXYHEMOGLOBIN
Hb + O2 = HbO2
2. Dissolved in Plasma
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Oxyhemoglobin
Oxyhemoglobin Dissociation
Curve
Fig. 8.8- Relationship between Amt of HbO2 and Partial
Pressure of O2
Hb O2 Saturation Increases as
Partial Pressure of O2 Increases
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Smoking and
Oxyhemoglobin
Comparison of the oxygen dissociation curves of normal blood,
blood containing 20%, 40% and 60% carboxyhemoglobin
(COHb), and blood from a severely anemic patient.
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BLOOD DOPING
or Blood Boosting
• The removal and then- reinfusion
of blood
• Done to temporarily increase blood volume
• Overloading would then increase O2 and
theoretically lead to INCREASED Endurance
• see Fig. 8.7- ability to run 5 miles faster
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Carbon Dioxide
Transport of CO2
Transport
CO2 + H2O
CA
H2 CO2
Carbonic Acid
H2 CO2
H+ + H-CO3
Bicarbonate ion
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Carbon dioxide is carried in the blood in three major forms:
1. dissolved (a little)
2. as bicarbonate and H+ (a lot)
3. attached to hemoglobin as a carbamino compound.
Loading of CO2 from tissue to blood and associated O2
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release from blood to tissue.
Anatomy of the Heart
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BLooD FloW through the HeaRt
Establishment of the four-chambered heart, along with the pulmonary
and systemic circuits, completely separates oxygenated from
deoxygenated blood. Fig8.9, p. 201
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Valves direct Blood Flow
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Blood Flow to the Body
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Blood Flow to the Body
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Blood Vessels and Flow Changes
35A
The Heart MUSCLE
Intercalated Discs
Myocardium
connect the individual
fibers of muscle to
act as ONE BIG FIBER:
Functional Syncytium
When one fiber contracts- all fibers
contract
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Conduction System
SA node
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SA
node
PACEMAKER
Conduction System
AV Node
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AV node
Bundle of His
PURKINJI FIBERS
Electrical System in Review
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Blood Supply to the Heart
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Blood Supply to the Heart
Coronary Vessels
Coronary Arteries
Coronary Veins
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Coronary vessels branch from Aorta:
L Coronary Artery & R Coronary Artery
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Blood Supply to the Heart
Coronary Veins
Coronary Sinus
Right Atrium
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CARDIAC OUTPUT
.
Q
L/min
= CARDIAC OUTPUT
SV (ML/BEAT) x HR (BEATS/MIN)
2 Components
STROKE VOLUME (SV)
HEART RATE (HR)
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CARDIAC OUTPUT
T RAINED
Bar 1
Bar 2
Bar 3
UNT RAINED
REST
0
10
20
30
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Cardiac Output increases for Endurance Athletes
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HEART RATE &
EXERCISE
HEART RATE
SUBMAX EXERCISE
REST
Max EXERCISE
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Exercise & Blood Flow
Vasoconstriction of Arterioles to Inactive Organs
Vasodilation of Arterioles to ActiveMuscles
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O2 Transport and
Endurance
• The arterial- mixed venous
difference (a- v O2 diff)
• Affected by:
–
the Amt. Of O2 extracted by muscles
– overall distribution of blood flow
– O2 extracted-–
a-v O2 diff --
ENDURANCE
»since less O in venous blood
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O2 Transport and
Endurance
Performance is affected by:
1. VO2 max
max O2 consumption
2. Anerobic Threshold
% of VO2 max utilized in relation to
Lactic acid production
3. Degree of Efficiency
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O2 Transport and
Endurance
Lactic Acid Accumulation begins only after a certain
% VO2 max
is reached- this starting point is
ANAEROBIC THRESHOLD
VO2
used
/ VO2 max x 100
= % VO2 max
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O2 Transport and Endurance
Efficiency of O2 Transport System
Amt of O2 Required during a given Exercise
level
If you require less of your VO2 max
you will be less fatigued and able to run
faster or farther=
MORE EFFICIENT
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O2 Transport &
Acclimatization
Acclimatization: the process of
adapting performance levels to a higher
Altitude
Physiological Changes:
Hyperventilation
Increased Hemoglobin Concentration
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