INTRODUCTIONINTRODUCTION

The Oxygen Transport The Oxygen Transport SystemSystem

I. Pulmonary VentilationMovement of Air in & out of the Lungs

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A. Minute Ventilation .. V V

The amount of Air ventilated The amount of Air ventilated by the lungs in one Minuteby the lungs in one Minute

.. V VEE

Volume Expired in One MinuteVolume Expired in One Minute

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Tidal Volume (TV)Tidal Volume (TV)The volume of Air ventilated per The volume of Air ventilated per

BreathBreath

Frequency (f)Frequency (f)The Number of Breaths/minuteThe Number of Breaths/minute

VVE E = TV x f= TV x f

MMinute ventilation =TV x finute ventilation =TV x f5

Ventilation during ExerciseVentilation during Exercise

ANT RISE

Rapid Rise

Slower Rise

levelingRapid

Decrease

Slower Decrease

0

5

10

15

20

25

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ANT RISE ExhaustionREST

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Ventilation as a Limit to Ventilation as a Limit to PerformancePerformance

•Performance is not limited by ventilation

•Ventilation will INCREASE out of proportion to workload so that

Ventilation becomes greater than Necessary-HYPERVENTILATIONHYPERVENTILATION -

•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 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

those areas of the body that air enters but

does not go into the alveoli - hence - NO GAS EXCHANGENO GAS EXCHANGE

DEAD SPACE

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Ventilation and Smoking

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• 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

• Pulmonary Ventilation

• Endurance

Ventilation and Smoking

• MAXIMUM Oxygen Consumption

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VOVO22max = the max max = the max rate rate at which O at which O2 2 can be can be

consumed per minuteconsumed per minute

• 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

Second Wind

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• 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

Stitch in Side

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II. GAS EXCHANGEGAS EXCHANGE

•TWO TYPESTWO TYPES–Alveolar Capillary Membrane–Tissue Capillary Membrane

Exchange of Oxygen & Carbon Exchange of Oxygen & Carbon DioxideDioxide

between the Air and Bloodbetween the Air and Blood

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Alveolar Capillary MembraneAlveolar Capillary Membrane

Thin layer of tissue that separates air in Aleoli Thin layer of tissue that separates air in Aleoli from blood in Capillariesfrom blood in Capillaries

1st EXCHANGE of O1st EXCHANGE of O22 and CO and CO22

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Capillary with RBC

Tissue Capillary MembraneTissue Capillary Membrane

Thin capillary membrane between blood and Thin capillary membrane between blood and tissues in bodytissues in body

2nd EXCHANGE of O2nd EXCHANGE of O22 and CO and CO22

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GAS EXCHANGE by GAS EXCHANGE by DIFFUSIONDIFFUSION

Movement of gases from higher concentrations to lower

concentrationsDiffusion GradientDiffusion Gradient=pp of gas in highest conc. Minus Minus

the pp of gas in venous blood

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Partial PressurePartial 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 Diffusion Gradients dependent on Partial pressures (p) of gas in 2 Partial pressures (p) of gas in 2

different areasdifferent areas

AlveolipO2 HIGH

BloodpO2 LOW

AlveolipCO2 LOW

BloodpCO2 HIGH

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Diffusion Capacity in Diffusion Capacity in AthletesAthletes

• 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 Combination-OOXYHEMOGLOBINXYHEMOGLOBIN

Hb + O2 = HbO2

2. Dissolved in Plasma 22

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. 25

BLOOD DOPING BLOOD DOPING or Blood Boostingor 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 faster26

Transport of CO2Carbon Dioxide

Transport

H2 CO2 CO2 + H2O

H2 CO2 H+ + H-CO3

CA

Carbonic Acid

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. 28

Anatomy of the HeartAnatomy of the Heart

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BLooD FloW through the BLooD FloW through the HeaRtHeaRt

Establishment of the four-chambered heart, along with the Establishment of the four-chambered heart, along with the pulmonary and systemic circuits, completely separates pulmonary and systemic circuits, completely separates

oxygenated from deoxygenated blood. Fig8.9, p. 201 oxygenated from deoxygenated blood. Fig8.9, p. 201 3030

Valves direct Blood FlowValves direct Blood Flow

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Blood Flow to the BodyBlood Flow to the Body

Blood Flow to the BodyBlood Flow to the Body

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Blood Vessels and Flow Blood Vessels and Flow ChangesChanges

35A

The Heart MUSCLEThe Heart MUSCLE Myocardium

Intercalated DiscsIntercalated Discsconnect the individual

fibers of muscle to

act as ONE BIG FIBER:

Functional SyncytiumFunctional SyncytiumWhen one fiber contracts- all fibers When one fiber contracts- all fibers

contractcontract

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Conduction System Conduction System SA SA nodenode

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SASAnodenode

PACEMAKERPACEMAKER

Conduction System Conduction System AV NAV Nodeode

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AV nodeAV node

Bundle of HisBundle of His PURKINJI PURKINJI FIBERSFIBERS

Electrical System in ReviewElectrical System in Review

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Blood Supply to the HeartBlood Supply to the Heart

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Blood Supply to the HeartBlood Supply to the Heart

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Coronary ArteriesCoronary ArteriesCoronary VeinsCoronary Veins

Coronary VesselsCoronary Vessels

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Coronary vessels branch from Aorta:L Coronary Artery & R Coronary Artery 41

Blood Supply to the HeartBlood Supply to the HeartCoronary VeinsCoronary Veins

Coronary SinusCoronary Sinus

Right AtriumRight Atrium42

CARDIAC OUTPUTCARDIAC OUTPUT..

QQ = CARDIAC OUTPUTCARDIAC OUTPUTL/min

2 Components2 ComponentsSTROKE VOLUME (SV)STROKE VOLUME (SV)

HEART RATE (HR)HEART RATE (HR)

SV SV ((ML/BEAT) x HR x HR ((BEATS/MIN)

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CARDIAC OUTPUTCARDIAC OUTPUT

0 10 20 30 40

REST

UNTRAINED

TRAINED Bar 1

Bar 2

Bar 3

Cardiac Output increases for Endurance Athletes44

HEART RATE & HEART RATE & EXERCISEEXERCISE

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HEART RATEHEART RATE

SUBMAX EXERCISE

Max EXERCISEMax EXERCISEREST

Exercise & Blood FlowExercise & Blood Flow

VasoconstrictionVasoconstriction of Arterioles to Inactive Organs

VasodilationVasodilation of Arterioles to ActiveMuscles46

• The arterial- mixed venous The arterial- mixed venous differencedifference (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

OO2 2 Transport and Transport and

EnduranceEndurance

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OO2 2 Transport and Transport and

EnduranceEndurancePerformance is affected by:

1. VO1. VO2 2 maxmaxmax O2 consumption

2. Anerobic Threshold2. Anerobic Threshold % of VO2 max utilized in relation to

Lactic acid production

3. Degree of Efficiency3. Degree of Efficiency

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Lactic Acid Accumulation begins only after a certain

% VO2 max is reached- this starting point is

ANAEROBIC THRESHOLDANAEROBIC THRESHOLD

VOVO2 2 used / VO/ VO2 2 max x 100 = % VOmax x 100 = % VO2 2 maxmax

OO2 2 Transport and Transport and

EnduranceEndurance

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OO2 2 Transport and EnduranceTransport and Endurance

Efficiency of Efficiency of OO2 2 Transport SystemTransport System

Amt of Amt of OO2 2 Required during a given Exercise Required during a given Exercise

levellevelIf you require less of your VOVO2 2 max max

you will be less fatigued and able to run you will be less fatigued and able to run faster or farther=faster or farther=

MORE EFFICIENTMORE EFFICIENT 50

OO2 2 Transport & Transport &

AcclimatizationAcclimatizationAcclimatization: the process of Acclimatization: the process of

adapting performance levels to a higher adapting performance levels to a higher AltitudeAltitude

Physiological Changes:Physiological Changes:HyperventilationHyperventilation

Increased Hemoglobin ConcentrationIncreased Hemoglobin Concentration

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