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Exercise Physiology final exam
Circulatory Adaptations, Respiration, Physiology of Training
61
Physiology
Undergraduate 4
05/02/2009

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Term
Cardiac Output Formula
Definition
Q = HR x SV
Term
Two systems that influence HR
Definition
PNS and SNS
Term
Parasympathetic (PNS) does....
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
Term
Sympathetic (SNS) influeces on CO
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
Term
Balence b/t SNS and PNS controlled by what?
Definition
Cardiovascular control center in medulla oblongata
Term
3 things that regulate SV
Definition
1) end-diastolic volume (EDV)
2) avg aortic BP
3) strength of ventricular contraction
Term
1) EDV facts
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)
Term
Frank Starling law
Definition
-streght of v entricular contraction ^ w/ ^ EDV stretch of vents
-^ EDV --> ^ cardiac fibers length --> ^ # of myosin crossbrdige interactions w/ actin --> ^ force production
Term
3 factors that ^ venous return (aka EDV)
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
Term
2) Avg Aortic BP
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
Term
3) Strength of Ventricle Contraction
Definition
circulating epinephrine-norepinephrine and SNS stimulate this
- increase contraction by ^ Ca available to myocardial cell
Term
Hemodynamics
Definition
study of physical principles of blood flow
Term
T/F: blood is more viscous than H2O
Definition
true
-results in increase difficulty for blood pumping

-# of RBCs affects this
Term
Factors that influence BF
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
Term
2 ways to increase oxygen delivery
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)
Term
Regulators of redistribution of BF during ex
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)
Term
Autoregulation
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
Term
As Ex begins metabolic rate increases. These changes follow:
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)
Term
Circulatory responses to ex
Definition
HR and BP

Depends on emotional influence (sns) and stuff...bad slide
Term
Transition from rest to Ex results in
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
Term
Incremental ex
Definition
HR and CO increase lineraly w/ work reate
Term
Double Product
Definition
-involved with incremental ex
-rate-pressure product
DP = HR x systolic BP
-used to prescribe ex to at risk patients
Term
Arm vs Leg Ex
Definition
-arm work has > hr and bp than leg work
-this is cause leg is vasoconstricted and its a huge M.
Term
Recovery from intermitten ex depends on these factors.
Definition
Subjects fitness, the environment (hot?), and duration and intensity of ex
Term
SV and HR effect in prolonged ex
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
Term
What turns on cardiovascular system at the onset of exercise?
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
Term
Lowdown on ventilation-perfusion relationships
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
Term
Ideal ventilation-to-perfusion ratio
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
Term
Major % of O2 and CO2 blood transport
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
Term
Loading and unloading
Definition
loading = O2 combining w/ Hb in lung.....

unloading = opposite of loading in tissues

deoxyHb + O2 <---> OxyHb
Term
factors that deterimine the oxyHb dissociation reaction direction.
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)
Term
What is 2-3 DPG
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
Term
Myoglobin
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
Term
CO2 transported in blood 3 ways
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)
Term
Diff of PCO2 in pulmonary capillaries
Definition
PCO2 in blood greater than PCO2 alveolus which results in CO2 crossing blood-gas interface
Term
expired ventilation _____________ at onset of ex
Definition
it increases abruptly
Term
ventilation response to prolonged ex in hot environment
Definition
-ventilation drifts upward during prolonged ex
-there is little diff in PCO2 b/t hot and cool environments
Term
ventilatory threshold (Tvent)
Definition
after surpassing 50-75% of VO2max ventilation increases exponentially
Term
What is the big diff in ventilation response b/t trained and untrained?
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
Term
Ventilatory regulation at rest
Definition
-contraction and relaxion of resp M controlled by somatic motor nuerons....
--motor neurons controled by respiratory control center in medulla oblongata
Term
Respiratory control center
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 )
Term
2 types of input to respiratory control center
Definition
1) neural
2) humoral
Term
Central chemo receptors
Definition
located in medulla and are affeced by diff in PCO2 and H+ of cerebrospianl fluid
Term
2 types of peripheral chemoreceptors
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
Term
Initial signal to drive cardiovascular system comes from _____
Definition
higher brain centers.

-this signal is fine tuned by feedback from chemoreceptors, mechanoreceptors, and barorecepotrs
Term
Do Lungs adapt to Ex Training?
Definition
-structural capacity of lungs = overbuilt
0lung exceeds demand for O2 and COO2 transport DEX

so the answer is no.
Term
3 Principles of Training.
Definition
Overload, Reversibility, and Specificity
Term
2 Research Designs:
Definition
Cross-sectional and Logitudinal
Term
VO2 max =
Definition
reproducible measure of hte capacity of hte cardiovascular system to deliver oxygenated blood to large M mass that is working
Term
How can some people have high vo2 but don't work out?
Definition
Genetic basis

40-66% of VO2 probably genetically predisposed
Term
Dalton's Law
Definition
total pressure of a gas mixture is equal to the sum of the pressure that each gas would exert independently
Term
Timeline of detraining
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
Term
1 week of detraining can = ______ loss of performance gained over_______ weeks
Definition
1 week not training causes 50% drop in what you gained over five weeks
Term
hyperplasma
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.
Term
body builder vs powerlifter workouts
Definition
bodybuilders (more reps less weight hypertrophy maximized)

powerlifters (less reps and more weight with big increase in capillary density)
Term
Basics on Hickson Study
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
Term
2 enzymes
Definition
Term
Blood lactate concentratioin
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
Term
Biochemical adaptations to training influence the physiological response to ex
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
Term
Citrate synthase (CS)
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)
Term
Structural and biochemical adaptations to endurance training
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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