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80 Cards in this Set
- Front
- Back
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Function of CV?
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-deliver oxygen
-remove waste -deliver nutrients -regulate temp |
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CV major adjustments to exercise?
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1-Cardiac output
2-Blood flow distribution |
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Heart- Right and left side?
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Right-Pulmonary circuit
Left- Systemic circuit |
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3 layers of heart?
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Epi
Myo Endocardium |
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Unique aspects of myocardium?
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-short branched fibers
-intercalated disc connections -Atrial/ventri separation -highly aerobic fibers, large # of mito |
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Arterial blood pressure
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Systolic: Contraction phase
Diastole: Relaxation phase Normal 120/80 High: 140/80 |
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What are factors that influences arterial blood pressure?
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-Heart rate increases
-Stroke vol increases -peripheral resistance (changes) -blood viscosity increases -blood volume increases |
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Electrical activity of heart?
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-specialized authorythmic cells
-SA/AV node/bundle branches/purk fibers |
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Define EKG and QRS etc...
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P-wave: Atria begins depolarizing
QRS: Ventricular depolarization begins at apex and progresses superiorly as atria repolarize. T-wave: Ventricular repolarization begins at apex and progresses superiorly. |
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Cardiac Output (Q)
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Determines performance.
=Stroke volume (SV)xHR |
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Factors affecting Q?
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-preload
-afterload -contractility -HR |
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Q at rest? Exercise?
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Rest: 5 L/min
Max: 25 L/min |
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Systolic/Diastolic pressure during exercise
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Rest: Slow. S: .3 sec D: .5 sec
Ex: Fast. S: .2 sec D: .13 sec |
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If HR goes up, Q goes up. What regulates HR?
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Para: (-) via vagus and SA/AV nodes
Symp: (+) via cardiac accelerator nerves, SA node, and ventricles (norepi) Hormones: Epi causes Na permeability. |
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What alters HR?
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Para withdrawl and sympth output. (para tone)
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Regulation of SVs?
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End-diastolic volume (EDV): *venous return and volume of blood in ventricles at the end of diastole (preload)
*Average aortic blood pressure: pressure at the heart must pump against to eject blood (afterload) *Strength of ventricular contraction (contractility) |
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Define Preload (Frank Starling's Law)
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-increased EDV=increased ventricular stretch=increased SV
-enhances actin/myosin interaction (sliding filament theory) -enhanced Ca kinetics: Ca and contraction -Graph x-ventr EDV y-ventricular perfomance, line upward-inside curve |
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Factors that affect EDV
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-increased venous return:
1-venoconstriction from symp output and smooth muscle contraction 2-muscle pump from muscle contraction and compression of veins 3-respiratory pump from increased abdominal pressure (inspiration) |
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Define afterload
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Load the heart must pump against (aortic pressure). causes total peripheral resistance, dilation and constriction of blood vessels and impacts pumping time (valve opens later, closes early)
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Define contractility
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-strength of ventricular contraction. It's all about Ca. Have myosin, actin. Increased EDV and increased Ca= increased Q. Intracellular Ca increases symp output to myocardium and circulating epi. Know graph.
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What are the physical characteristics of blood?
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Bottom: Hematocrit (38-45%) RBC
Middle: WBC and platelets Top: Plasma |
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What are the factors affecting blood flow?
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-Pressure gradient (Pressure goes down over time)
-vessel diameter -vessel length -blood viscosity. |
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Define Poiselle's equation
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P1 to P2
F=(P1-P2)pi*R^4/8LN takes flow, pressure, radius, vessel length, viscosity into account. Small change in diameter=large change in blood flow. |
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Increased O2 delivery accomplished by...
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1-increased cardiac output
2-redistribution of blood flow to skeletal muscles |
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What are the regulations of muscle blood flow during exercise?
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-Autoregulation (local) override of symp output and local vasodilation.
-meets local blood flow demand -activators (metabolic byproducts) are adenosine, PO2, PCO2, pH, nitric oxide (NO) |
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CV control center
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Located in medulla and pons (brainstem area), it receives inputs from central command and several afferents, also directly affected by PO2 and PCO2
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Define Central Command
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It's the initial activator. Higher brain center is associated with motor output, routed directly through CV center, and at and during onset of exercise. (vasoconstriction, higher HR, higher contraction force)
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Factors that affect CVC
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Chemoreceptors, hypothalamus, baroreceptors, muscle afferents
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Central command affects what...
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chemo and mechanoreceptors in skeletal muscles, which will then affect CVC to adapt blood vessels and heart. CVC also affected by baroreceptors.
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Look at graphs on page...
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207
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Define Skin blood flow
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Hypothalamus acts as the thermostat. Affected by temp, symp output, baroreceptors, local neurochemical vasodil. (sweat response up, skbf up)
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Define CV drift
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Due to dehydration, increased skbf (rising body temp) and increased symp output
1-prolonged exercise 2- up heat stress Graphs: Q remains stable Stroke volume decreases HR increases. |
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How does the fine-tune works for CVC
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Baro: aortic and carotid pressure/stretch
Chemo: aortic/carotid bodies (CO2, pH, O2) and muscles Mech: movement. All of those fine-tunes the CVC. |
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Differentiate pulmonary and cellular respiratory
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P: Gas exchange
C: cell/muscles |
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Define ventilation and diffusion
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V: movement of air
D: movement down a gradient. (Pressure gradient, PO2, PCO2) |
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Identify the upper/lower or conducting/respiratory zones
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Conductory: trachea, primary bronchus, bronchial tree, terminal bronchioles
Respiratory: Alveolar sac, alveolus, respiratory bronchioles |
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Purpose of conducting and respiratory zones?
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C: Humidifies, warms, filters air
R: Exchange gases. (Alveolar sacs/aveoli: 300 million) |
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name the muscles of inspiration and expiration
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I: SCM, Scalene, Ex/In intercostals, diaphragm
E: In intercostals, all obliques and rectus abdominis. |
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Pleura of lungs?
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. Parietal pleura lines the thoracic walls and diaphragm, visceral pleura adheres to the outer surface of the lungs. Between both pleura is a thin lubricant, allowing gliding action of each other.
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Mechanics of breathing
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Inspiration: (Active process) diaphragm pulls downward, lowering intrapulmonary pressure.
Expiration: (rest:passive, exer:active) diaphragm relaxes, rising intrapulmonary pressure. Resistance to airflow determined by airway diameter. |
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Define Pulmonary Ventilation. Ve
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amount of air moved in or out of the lungs per minute. (L/min)
-Product of tidal volume (Vt) and breathing frequency (fb) Rest: 7 L/min Max: 130-150 L/min |
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Partial pressure/Dalton's Law
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Total pressure of gas mixture is equal to sum of the pressure of each gas independently.
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Partial pressure of O2
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PO2= Air is 20% oxygen, expressed as a fraction, .20. Total pressure of air is 760 mmHg, so PO2= .2 x 760= 159 mmHG
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Air composition
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O2=20%
N2= 79% CO2= 1% |
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Altitude pressuref
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High alt: PO2= 56 mmHg
Med alt: PO2= 100 mmHg Low alt: PO2= 130 mmHg Gradients are steeper at low elevation, shallow at high alt, thus need more 'push'. |
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Pressure gradient of PO2 and PCO2 throughout body
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Lung exchange: PO2= 105, PCO2=40. After cell exchange of O2, CO2, PO2 is 40, PCO2=46.
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Oxygen transport
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Hemoglobin: high affinity for O2, 99% of O2 is bound to it. Know the disassociation curve.
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O2-Hb Disassociation curve with effects of pH
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Blood pH declines during heavy exercise, results in rightward shift of curve. Bohr's effect: favors unloading of O2 to tissues. Know Graph: less saturation of O2.
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O2-Hb disassociation curve with temp
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Increase temp results weaker O2-Hb bond, results in rightward shift of curve, easier unloading of O2 to tissues. Graph: Less saturation with increasing temp.
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Oxygen transport in muscle regarding myoglobin and hemoglobin
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Myoglobins bind O2 in muscles, has higher affinity than hemoglobin, maintains O2 flux from blood to mito, greater concentration in type 1 fibers. Know graph: Low PO2, venous blood- myo has more. High PO2, arterial blood, more similar.
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CO2 transport methods
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Dissolved: 7% (more soluble than O2)
Hemo: 20% Carbaminohemoglobin BiCarb: 70%. CO2 into HCO3 to H and H2CO3, carbonic anhydrase catalyzes CO2 to Carbonic acid, dynamic at muscles and lungs |
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Control of ventilation?
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(similar to CVC)
Respiratory Control Center: initial stimulus. Chemo: at medulla- cerebrospinal fluid pH and PCO2. At peripheral (aoritic/carotid)- pH, PCO2, PO2, K. Neural input: motor cortex, skeletal muscles (mech and chemo) |
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What are some limitations to performances (respiratory speaking)
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Exercise induced hypoxemia: desaturation at high intensity exercise and blood flow (Q) exceeds pulmonary diffusion capacity. Graph: less time of contact between blood/capillary.
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heat Production
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-Metabolism (biggest factor), biochemical reactions are inefficient and 75% of energy are released as heat and is dependent on exercise/metabolic rate. (breakdown of ATP)
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4 methods of heat transferral
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1-Evaporation (exercise and rest))
2-Radiation (rest) 3-Convection (rest) 4-Conduction |
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Graph of ambient temp and heat loss
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Low temp: Convective and Radiative heat loss. High temp: Evaporative heat loss. Crosses each other at 20 C
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Humidity and heat loss?
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80% heat lost during exercise, depends on core temp, sweating and evap. Core temp increases with humidity faster than dry. (Equilibrium)
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What monitors body temp and how?
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Hypothalamus (thermostat) and thermoreceptors: Central-blood/core temp, Peripheral-skin temp. Info goes through hypothalamus, which controls skbf and sweat response.
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Define environmental heat stress:
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Affected by air temp, humidity, air velocity and thermal radiation. Wet Bulb Globe Thermometer takes those into account.
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WBGT stats
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>28 C: very high risk
23-28 C: High risk 18-23 C: Mod risk <18 C: Low risk of heat injury <10 C: Low risk of hyperthermia, possible hypothermia |
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What are the stimulus for acclimatization?
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Elevated Core temp is primary stimulus for thermoregulatory adaptations- thus purpose is to regulate core temp, HR, blood volume.
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Graph of unacclimatized and acclimatized
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Core temp and HR drops for trained.
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In heat acclimatization, plasma volume response happens by:
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1.Sweat/heat/fluid balance, ADH/aldosterone response- expands plasma volume by 10-12%. Benefits are cardiac performance and muscle/skin blood flow
2. Earlier onset of sweating 3. Higher sweat rate (less heat accumulation) 4. Reduced NaCl loss in sweat, more dilute sweat (sweat gland adaption and response to increased aldosterone secretion. |
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What is the time frame for heat adaption?
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Acclimatization: 2-weeks with regular exposure. Plasma volume increases 4-6 days, enhanced sweat response 12-14 days.
Loss of adaption w/out exposure: measurable in 7 days, complete in 28 days |
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Graph of fluid affecting HR
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No fluid- HR rises dramatically
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Fluid consumption and composition during exercise
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Consumption: 150-200 ml/15 min
Composition: Glucose- 6-8% of sport drinks, more better but less tolerable (30-50 g CHO/hr) Electrolytes- fluid absorption and palatability. Exercise duration and composition: Exercise<60 min: water Exercise >60 min: 8% CHO, electrolytes, >500 ml/hr Exercise > 3 hrs: 8% CHO, electrolytes, >500 ml/hr |
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Principles of training?
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Overload, specificity, reversibility
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Overload minimum requirement?
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Endurance: 50% muscle mass, 15-20 min of continuous exercise; 3-5 days per week, 50-60% VO2 max. Level of adaption related to training.
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What are the myocardial adaptions to training?
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Heart pumps more blood- by increasing myocardial mass and left ventricle volume, thus increasing SV.
Endurance: Volume overload adaption Resistance: Pressure overload adaption. |
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Heart structure for each training method?
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Endurance: Volume overload: increases heart volume and muscle mass/thickness
Normal: Regular thickness and volume. Resistance: Pressure overload: Same volume but increased mass/thickness. |
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Training results for HR?
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Reduced HR, increased para, muscular and SV change.
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Training results for SV?
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Volume increases (15-20%) and increased LV volume/mass. (Rest: 60-100mL, Exer: 100-180 mL)
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Training results on Q?
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Resting/submaximal: No change
Maximal: 15-20% increase with training |
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Arterial-Venous oxygen difference?
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Content: O2 A- 20/100 mL V: 14/100 mL
avO2 difference: Rest- 6 Max-16 Change with exer: arterial level same, reduced venous content. |
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Training results on VO2max
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Resting: same
Sub: Same, if change, efficiency and learning, weight loss Max: increases |
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VO2max increases with training because...?
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Q and blood flow distribution (myocardial changes, blood volume, blood composition, capillary)
Oxygen extraction: mito adaptions (increased enzyme activities, myoglobin content) |
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Factors affecting potential alterations in VO2max?
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-Initial condition
-heredity/genetics -age -gender -specificity |
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Blood change after training?
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Pretraining: 44% hematocrit with volume of 2.2 L.
Posttraining: 41% hematocrit with volume of 2.4. RBC and plasma increases, hemodilution increases. |
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Muscle flow after training?
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1. Increased capillarization
2. Increased capillary recruitment Result: Improved blood flow distribution |
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Mito after training?
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Size, number, and development, enzymes increases. Consider CV changes with metabolic changes.
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