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INTRODUCTION. The Oxygen Transport System. I. Pulmonary Ventilation Movement of Air in & out of the Lungs. 3. A. Minute Ventilation . V The amount of Air ventilated by the lungs in one Minute . V E Volume Expired in One Minute. 4.
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I. Pulmonary VentilationMovement of Air in & out of the Lungs 3
A. Minute Ventilation. VThe amount of Air ventilated by the lungs in one Minute. VEVolume Expired in One Minute 4
Tidal Volume (TV)The volume of Air ventilated per BreathFrequency (f)The Number of Breaths/minuteVE = TV x fMinute ventilation =TV x f 5
Ventilation during Exercise REST Exhaustion 6
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 7
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 8
II. Alveolar Ventilation DEAD SPACE those areas of the body that air enters but does not go into the alveoli - hence - NO GAS EXCHANGE 9
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 10
Ventilation and Smoking • Pulmonary Ventilation • Endurance • MAXIMUM Oxygen Consumption VO2max = the max rate at which O2 can be consumed per minute 11
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 12
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 13
II. GAS EXCHANGE Exchange of Oxygen & Carbon Dioxide between the Air and Blood • TWO TYPES • Alveolar Capillary Membrane • Tissue Capillary Membrane 14
Alveolar Capillary Membrane Thin layer of tissue that separates air in Aleoli from blood in Capillaries 1st EXCHANGE of O2 and CO2 15
Tissue Capillary Membrane Capillary with RBC Thin capillary membrane between blood and tissues in body 2nd EXCHANGE of O2 and CO2 16
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 17
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 18
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 19
Diffusion Capacity in Athletes • Alveolar- Capillary diffusion is greater during max exercise in (endurance) athletes than Nonathletes • see Table 8.5 20
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 22
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 23
Smoking andOxyhemoglobin 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 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 26
Carbon Dioxide Transport Transport of CO2 CA CO2 + H2O H2 CO2 Carbonic Acid H2 CO2 H+ + H-CO3 Bicarbonate ion 27
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
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 30
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 35
Conduction System SA node 36 SA node PACEMAKER
Conduction System AV Node 37 AV node Bundle of His PURKINJI FIBERS
Blood Supply to the Heart Coronary Vessels Coronary Arteries Coronary Veins 40 40
Coronary vessels branch from Aorta: L Coronary Artery & R Coronary Artery 41
Blood Supply to the Heart Coronary Veins Coronary Sinus Right Atrium 42
CARDIAC OUTPUT . Q = CARDIAC OUTPUT SV (ML/BEAT) x HR (BEATS/MIN) L/min 2 Components STROKE VOLUME (SV) HEART RATE (HR) 43
CARDIAC OUTPUT Cardiac Output increases for Endurance Athletes 44
HEART RATE & EXERCISE HEART RATE SUBMAX EXERCISE Max EXERCISE REST 45
Exercise & Blood Flow Vasoconstrictionof Arterioles to Inactive Organs Vasodilation of Arterioles to ActiveMuscles 46
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 47
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 48
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 49