The Oxygen Transport System

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INTRODUCTION
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The Oxygen Transport System
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I. Pulmonary VentilationMovement of Air in out
of the Lungs
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A. Minute Ventilation . VThe amount of Air
ventilated by the lungs in one Minute.
VEVolume Expired in One Minute
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Tidal Volume (TV)The volume of Air ventilated
per BreathFrequency (f)The Number of
Breaths/minuteVE TV x fMinute ventilation
TV x f
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Ventilation during Exercise
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
  Necessary-HYPERVENTILATION -
• 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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Capillary with RBC
Tissue Capillary Membrane
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 PressureThe 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
Blood pO2 LOW
Alveoli pO2 HIGH
Alveoli pCO2 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
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Transport of Gases by the Blood
O2 and CO2 are carried in the blood
by 1.Chemical Combination-OXYHEMOGLOBIN Hb O2
HbO2 2. Dissolved in Plasma
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Oxyhemoglobin
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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. 25
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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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Transport of CO2
Carbon Dioxide Transport
CA
CO2 H2O
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 release from blood to tissue.
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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
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The Heart MUSCLE
Myocardium
Intercalated Discs 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
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Conduction System AV Node
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AV node
Bundle of His
PURKINJI FIBERS
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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
CARDIAC OUTPUT
SV (ML/BEAT) x HR (BEATS/MIN)
L/min
2 Components STROKE VOLUME (SV) HEART RATE (HR)
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CARDIAC OUTPUT
Cardiac Output increases for Endurance Athletes
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HEART RATE EXERCISE
HEART RATE
SUBMAX EXERCISE
Max EXERCISE
REST
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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 O2 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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