Term
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Definition
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Term
| Two systems that influence HR |
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Definition
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Term
| Parasympathetic (PNS) does.... |
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Definition
-starts in cardiovascular control center in medulla oblongota
-makes up vagus nerve
-Acetylcholine decreases SA and AV via hyper-polarization.
-reduces HR
-Parasympathetic tone = vagus impulses that affect nodes at rest
-initial ex increase due to w/drawl of pns |
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Term
| Sympathetic (SNS) influeces on CO |
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Definition
-increases HR
-reaches heart via cardiac accelerator nerves which hits SA node and vetricles.
-releases norepinephrine wich acts on beta receptors.
-this ^ HR and contraction |
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Term
| Balence b/t SNS and PNS controlled by what? |
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Definition
| Cardiovascular control center in medulla oblongata |
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Term
| 3 things that regulate SV |
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Definition
1) end-diastolic volume (EDV)
2) avg aortic BP
3) strength of ventricular contraction |
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Term
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Definition
-aka preload
-frank - starling law = strength of vent contraction ^ w/ ^ EDV (stretch of vents) which lengthens cardiac fibers --> ^ contraction force
-^ rates of venous return = ^ EDV (explains ^ SV during upright ex) |
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Term
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Definition
-streght of v entricular contraction ^ w/ ^ EDV stretch of vents
-^ EDV --> ^ cardiac fibers length --> ^ # of myosin crossbrdige interactions w/ actin --> ^ force production |
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Term
| 3 factors that ^ venous return (aka EDV) |
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Definition
1) VAsoconstriction (^ VR via V blood vol and capacity of veins, occurs via SNS contriction of veins that drain sk M)
2) Muscle Pump (rhythmic Sk M contractions compreses veins moving B to H. 1 way valves stop backflow)
3) Respiratory Pump (inspiration V chest pressure and ^ abdominal pressure. this is main factore for ^ venous return to H during EX |
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Term
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Definition
-aka Afterload
-pressure in L vent must > than pressure in aorta to eject blood
-SV inverse to afterload (^ aortic BP = V SV)
-afterload minimized during ex via arteriole dilation |
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Term
| 3) Strength of Ventricle Contraction |
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Definition
circulating epinephrine-norepinephrine and SNS stimulate this
- increase contraction by ^ Ca available to myocardial cell |
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Term
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Definition
| study of physical principles of blood flow |
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Term
| T/F: blood is more viscous than H2O |
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Definition
true
-results in increase difficulty for blood pumping
-# of RBCs affects this |
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Term
| Factors that influence BF |
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Definition
1) Pressure (high vs low results in flow)
2) Resistance (decreased resistance = ^ BF)
-proportional to vessel length and blood viscosity
-diameter of blood vessel very important
-greatest resistance found in arterioles |
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Term
| 2 ways to increase oxygen delivery |
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Definition
1) increase CO (CO increase proportional to metabolic need of sk M; linear to % max VO2; untrained SV doesn't ^ pass 40-50% VO2 max)
Frick Equation = VO2 =Q x (a-vo2 diff)
2) Redistribution of Blood flow during ex
(15% of total CO directed towards working Sk M and decrease in BF towards skin and abdominal organs not involved in work out) |
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Term
| Regulators of redistribution of BF during ex |
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Definition
1) arteroles in sk M have high vascular resistance at rest SNS vasoconstriction produces low BF to M at rest
2) REdistribution of BF during ex (aka autoregulation) |
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Term
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Definition
instrinsic control of BF by changei n local metabolites (ie: O2 tension, pH, K, adenosine, NO)
-this is most important factor in redistribution
-causes vasodilation resulting 20x ^ in FB to working M |
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Term
| As Ex begins metabolic rate increases. These changes follow: |
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Definition
1) decreases O2 tension (b/c of increase O2 extraction)
2) Nitric Oxide (NO) [produced in arterioles and promotes relaxtion and vasodilation of arterioles in working M]
3) Adenosine (promotes vasodilation)
4) decrease pH (casued by ^ CO2 and increased lactic acid break down) |
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Term
| Circulatory responses to ex |
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Definition
HR and BP
Depends on emotional influence (sns) and stuff...bad slide |
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Term
| Transition from rest to Ex results in |
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Definition
| rapid increase in HR, SV, and CO (1 sec of M contraction) if ex is below lactate threshold then steady state is achieved ast |
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Term
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Definition
| HR and CO increase lineraly w/ work reate |
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Term
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Definition
-involved with incremental ex
-rate-pressure product
DP = HR x systolic BP
-used to prescribe ex to at risk patients |
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Term
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Definition
-arm work has > hr and bp than leg work
-this is cause leg is vasoconstricted and its a huge M. |
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Term
| Recovery from intermitten ex depends on these factors. |
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Definition
| Subjects fitness, the environment (hot?), and duration and intensity of ex |
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Term
| SV and HR effect in prolonged ex |
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Definition
decreased SV and increased HR aka CARDIOVASCULAR DRIFT - due to influence of ^ BT on dehydration and decreased plasma vol
-hot environment exaggerates this drift |
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Term
| What turns on cardiovascular system at the onset of exercise? |
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Definition
Central command theory.
---central command = motor signal developed w/in brain that initiates cardio changes.
---response to ex is fine-tuned by feedback from M chemoreceptors, M mechanoreceptors, and arterial baroreceptors to cardio control center |
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Term
| Lowdown on ventilation-perfusion relationships |
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Definition
| normal gas exchange needs matching ventilation to BF in order for exchange to occur. if this doesn't happen then there is no exchange |
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Term
| Ideal ventilation-to-perfusion ratio |
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Definition
V/Q >= 1.0 (this is optimum)
-V/Q in reality is rarely ideal and varies according to what part of lung is looked at (lung base is over perfused aka V/Q = <1)
--V/Q that are > 0.5 are so so ok
--light ex may increase v/q |
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Term
| Major % of O2 and CO2 blood transport |
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Definition
--99% of O2 binds to Hb
--CO2 becomes bicarbonate (HCO3)
----1 Hb transports 4 O2
# of O2 that can be moved per blood unit depends on Hb concentration (norn conc: males = 150 g/l of blood. Females = 130 g/l of blood) this changes in supersaturation |
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Term
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Definition
loading = O2 combining w/ Hb in lung.....
unloading = opposite of loading in tissues
deoxyHb + O2 <---> OxyHb |
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Term
| factors that deterimine the oxyHb dissociation reaction direction. |
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Definition
1) PO2 of the blood (high PO2 > while low PO2 <)
2) the affinity b/t Hb and O2
--low ph decreases affinity (Bohr effect) right shift
--temp is inverse to blood temperature (V temp < while ^ temp >)
increased temp weakens affinity
-DEX: M have ^ temp which shifts curve right which facilitates unloading of O2 to tissues) |
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Term
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Definition
DPG = diphosphoglycerate
--byproduct of RBC's glycolysis, combines w/ Hb and decreases Hb affinity for O2 results in right shift in OxyHb dissociation curve |
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Term
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Definition
Oxygen binding protein found in sk M and cardiac M fibers
--acts as shuttle to move oxygen from cell membrane to mitochondria
--large # found in slow twitch fibers
--1/4 weight of Hb
--its O2 stores serve as O2 reserve for time b/t initial M contraction and delivery of oxygen
-this store must be replinish and thus adds to oxygen debt |
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Term
| CO2 transported in blood 3 ways |
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Definition
1) dissolved CO2 (10% of CO2)
2) CO2 bound to Hb (carbaminoHb and is 20% of CO2)
3) Bicarbonate [HCO3] this is 70% of CO2 in body
when bicarbonate diffuses out of blood into lungs Cl replaces the lost electron (this is called the chloride shift) |
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Term
| Diff of PCO2 in pulmonary capillaries |
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Definition
| PCO2 in blood greater than PCO2 alveolus which results in CO2 crossing blood-gas interface |
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Term
| expired ventilation _____________ at onset of ex |
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Definition
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Term
| ventilation response to prolonged ex in hot environment |
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Definition
-ventilation drifts upward during prolonged ex
-there is little diff in PCO2 b/t hot and cool environments |
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Term
| ventilatory threshold (Tvent) |
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Definition
| after surpassing 50-75% of VO2max ventilation increases exponentially |
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Term
| What is the big diff in ventilation response b/t trained and untrained? |
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Definition
-untrained vent stays w/in 10-12 mmHg of Norm
-Trained PO2 drops 30-40 mmHg at near max work
---low PO2 = hypoxemia (40 % of athletes show this)
==this is unknown why |
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Term
| Ventilatory regulation at rest |
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Definition
-contraction and relaxion of resp M controlled by somatic motor nuerons....
--motor neurons controled by respiratory control center in medulla oblongata |
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Term
| Respiratory control center |
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Definition
-drive to breath comes from medulla oblongata
-2 areas in Pons control
1) apneustic area (inspiratory cutoff switch)
2) pneumotaxic area (fin tunes apneustic activity ) |
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Term
| 2 types of input to respiratory control center |
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Definition
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Term
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Definition
| located in medulla and are affeced by diff in PCO2 and H+ of cerebrospianl fluid |
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Term
| 2 types of peripheral chemoreceptors |
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Definition
1) aortic bodies (located in aortic arch)
2) carotid bodies ( located in carotid and more important than aortic)
----both respond to increasing H+ conc in arts and PCO2 |
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Term
| Initial signal to drive cardiovascular system comes from _____ |
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Definition
higher brain centers.
-this signal is fine tuned by feedback from chemoreceptors, mechanoreceptors, and barorecepotrs |
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Term
| Do Lungs adapt to Ex Training? |
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Definition
-structural capacity of lungs = overbuilt
0lung exceeds demand for O2 and COO2 transport DEX
so the answer is no. |
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Term
| 3 Principles of Training. |
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Definition
| Overload, Reversibility, and Specificity |
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Term
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Definition
| Cross-sectional and Logitudinal |
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Term
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Definition
| reproducible measure of hte capacity of hte cardiovascular system to deliver oxygenated blood to large M mass that is working |
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Term
| How can some people have high vo2 but don't work out? |
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Definition
Genetic basis
40-66% of VO2 probably genetically predisposed |
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Term
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Definition
| total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently |
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Term
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Definition
1st 12 days ( decreased vo2 b/c of decreased sv due to low plasma vol)
21st - 84th day (vo2 max decrease due to a-vo2 diff decrease...this is associated w/ mitochondria decrease while cap density stays the same)
-overall oxidative capacity of sk M reduced |
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Term
| 1 week of detraining can = ______ loss of performance gained over_______ weeks |
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Definition
| 1 week not training causes 50% drop in what you gained over five weeks |
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Term
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Definition
this is a hypothetical increase in the # of M fibers b/c of exercise.
not know if this exists but a study suggested that it occureed. |
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Term
| body builder vs powerlifter workouts |
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Definition
bodybuilders (more reps less weight hypertrophy maximized)
powerlifters (less reps and more weight with big increase in capillary density) |
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Term
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Definition
on intereactinos b/t strenght and endurance training
--E had increased vo2 first weeks but then it plataus. by adding S to E the S increased 30%, time to exhaustion increased 14 minutes but vo2 stayed the same
-cross-training may be counterproductive |
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Term
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Definition
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Term
| Blood lactate concentratioin |
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Definition
balance b/t production and removal
--lactate production during exercise via NADH, Pyruvate and LDH in cytoplasm
----Blood pH affected by blood lactate concentration |
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Term
| Biochemical adaptations to training influence the physiological response to ex |
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Definition
--sympathetic nervous system (decrease E/NE)
--cardiorespiratory system (decrease HR and ventilation)
---due to:
-------reduction in feedback from M chemorecepotrs and reduced # of motor units recruited.
this is demonstarted in one leg training studies |
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Term
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Definition
marker of mitochoncrea oxidative capacity.
during light to moderate ex: ^ CS in high oxidative fibers (type I and IIa)
--Strenuous ex training : ^ CS in low oxidative fibers (type IIb) |
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Term
| Structural and biochemical adaptations to endurance training |
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Definition
^ mitochondrial #, ^ oxidative enzymes (krebs cycle [citrate synthase], fatty acid cycle [beta oxidation], electron transport chain), ^ NADH shuttling system, change in type of LDH
---these adaptations are quickly lost w/ detraining |
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