KINES 380 Unit 4

Exam 2

2 major adjustments to blood flow during exercise

increased cardiac output and redistribution of cardiac output

hypertension is a BP above _______ mmHg

140/90

contraction of the heart depends on

electrical stimulation of myocardium

graded exercise test to see how electrical activity of heart responds

stress test

total volume of blood pumped by the heart per minute

cardiac output

cardiac output equation

CO = HR x SV

cardiac output depends on what 2 things

training state and stroke volume

3 factors that increase stroke volume

sympathetic nerves, contraction strength, EDV

factor that decrease stroke volume

MAP

heart rate is increased by

sympathetic nerves

heart rate is decreased by

parasympathetic nerves

heart rate _________ at the onset of exercise

increases

the volume of blood in the ventricles at the end of diastole (“preload”)

end-diastolic volume (EDV)

pressure in the heart must pump against to eject blood (“afterload”)

mean arterial pressure (MAP)

strength of ventricular contraction is enhanced by (2)

circulating epinephrine and norepinephrine, direct sympathetic stimulation of heart

low resting heart rate is due to

parasympathetic tone

Frank-starling mechanism

greater EDV = more forceful contraction

the Frank-starling law is due to

lengthening of cardiac fibers (increased cross-bridges)

end-diastolic volume is dependent on

venous return

venous return is increased by (3)

venoconstriction, skeletal muscle pump, respiratory pump

blood flow is ______________ to the pressure difference between two ends of the system

directly proportional

blood flow is _____________ to resistance

inversely proportional

blood flow equation

blood flow = right arterial (^) pressure / resistance

pressure is ___________ to the difference between MAP and right arterial pressure (^)

proportional

resistance equation

resistance = (length x viscosity) / radius^4

O2 demand by muscles is _________ at rest

lower

increased O2 delivery is accomplished by (2) during exercise

increased cardiac output, redistribution of blood flow

during exercise, heart rate increases _________

linearly

adult HR calculation

HR = 220 - age

child HR calculation

HR = 208 - (0.7 x age)

stroke volume increases, then

plateaus at ~40% VO2 max (no plateau in highly trained)

skeletal muscle vasodilation has autoregulation, which

increases blood flow to meet metabolic demands of tissues

changes in HR and BP depend on (3)

type/intensity/duration of ex, environmental condition, emotional influence

systolic BP ________ with exercise intensity

increases

how hard the heart has to work, increases linearly with exercise

double product

double product equation

double product = HR x systolic BP

recovery of HR and BP between bouts of exercise depend on (3)

fitness level, temp and humidity, duration/ intensity

cardiac output is _________ during prolonged exercise

maintained

there is a gradual __________ in SV during prolonged exercise due to (2)

decrease, dehydration and decreased plasma volume

there is a gradual __________ in HR during prolonged exercise due to (1)

increase, cardiovascular drift

pulmonary respiration

exchange of O2 and CO2 in lungs

cellular respiration

O2 utilization and CO2 production in lungs

2 purposes of the respiratory system during exercise

gas exchange and regulation of acid-base balance

major muscle of inspiration

diaphragm

asthma results in a

bronchospasm = narrowing of airways

exercise-induced asthma is a

bronchospasm during/immediately after exercise

increased airway resistance due to constant narrowing and decreased expiratory flow

chronic obstructive lung disease (COPD)

amount of air moved in/out of lungs per minute (V) =

V = tidal volume (Vt) x breathing frequency (f)

volume of air that reaches respiratory zone

alveolar ventilation (Va)

volume of air remaining in conducting airways

dead-space ventilation (Vd)

total pressure of gas that each gas would exert independently

Dalton’s law

the rate of diffusion is proportional to the tissue area, the diffusion of the coefficient of the gas and the difference in partial pressure of gas on the two sides of the tissue, and inversely proportional to the thickness

Fick’s law

when standing, most of the blood flow is

to the base of the lung

during exercise, more blood flow is

to the apex of the lung

____% of O2 is transported bound to hemoglobin (Hb)

99%

the amount of O2 transported per unit volume of blood is dependent on

Hb concentration

3 ways CO2 is transported in the blood

dissolved in plasma (10%), bound to Hb (20%), bicarbonate (70%)

increased ventilation results in (3)

CO2 exhalation, increases pH, decreases PCO2

decreased ventilation results in (3)

buildup of CO2, decreased pH, increased PCO2

training ________ ventilatory response to exercise

reduces

is the pulmonary system a limitation during low-moderate exercise intensity?

no

is maximal exercise a limitation during low-moderate exercise intensity?

yes

the difference between O2 content of arterial and mixed-venous blood

aVO2 difference

aVO2 ________ as exercise increases

increases

________ drives how much O2 is extracted or dropped off

affinity

at different places of the body, PO2 is different

O2-Hb dissociation curve

affinity of O2 and Hb is _______ at a lower PO2

lower

VO2 max =

HR max x SV max x (aVO2) max

improvements in VO2 max (3)

~50% increase in SV and aVO2 max, short duration training increases SV, long duration training increases aVO2

marker of mitochondrial oxidative capacity

citrate synthase (CS)

mitochondrial adaptations effects of exercise intensity

55%, 65%, or 75% VO2 max increases CS in 2a fibers

mitochondrial adaptations effects of exercise duration

no difference in 2a, increased CS activity in 2x fibers w/ high-long

endurance training improves

muscle antioxidant capacity

endurance training reduces

O2 deficit

muscle mitochondria _______ within ___ week(s)

double, 5

loss of ___% muscle mitochondrial gain within ___ week(s)

50%, 1

muscle mitochondrial regain requires ____ week(s) of retraining

3-4

training ________ is most important in improving VO2 max

intensity

what measures pulmonary volume?

spirometer

factors that increase VO2 max (2)

increased cardiac output and aVO2 difference

Bohr effect

rightward shift in curve = more acidic blood (O2-Hb)

cardiac output at rest

4 L/min

cardiac output during exercise

20-25 L/min