blood flow and gas transport

stroke volume- amount of _____ pumped by either the left or right ventricle per ____(mL)

blood, beat

cardiac output (Q)- amount of _____ ______ by either the left or right ventricle of the heart per ______ (L/min)

• both the left and right ventricles must have the ____ cardiac output so the blood flow through the pulmonary and systemic circuits is maintained _______

blood pumped, minute, same, equally

cardiac output = _____ ____ x _____ ______

heart rate x stroke volume

resting Q= __ bpm x __ mL = ____ mL (_L/ min)

62, 80, 4960, 5

maximum Q = ___ bpm x ___ mL (sedentary) to ___ mL (athlete) = __ to __ L/min

200, 100, 150, 20-30

since the blood transports ______, when cardiac output increases in exercise more oxygen will be transported to the working muscles, this relationship can be expressed by the ____ equation

oxygen, fick

fick equation:

VO2 = __ x __ x (_ - ___) diff

• VO2 = ______ uptake or utilization by the tissues in the body

• (a- VO2) diff = arterial- mixed venous ______ difference (how much oxygen is extracted at tissue capillary beds)

HR x SV x (a-VO2), oxygen, oxygen

therefore, in order to increase oxygen uptake, you must increase _______ ______ or extract more _______ from the arterial blood

cardiac output, oxygen

in general, the higher the maximal ______ volume → higher maximal _______ output → higher maximum _______ uptake (VO2 max)

stroke, cardiac, oxygen

the cardiac output required for a _____ workload is reasonably _______ for trained and untrained subjects

given, similar

to achieve the cardiac output required for a given workload, trained subjects will have a lower exercise _____ ____, as they have a higher ______ ______ than untrained subjects

heart rate, stroke volume

for any given subject, heart usually increases ________ with increasing workload until the subject’s _______ heart rate is reached

linearly, maximum

the heart rate at a given oxygen uptake is higher when the exercise is performed with the ____ than with legs due to smaller ________ mass, increased intra-thoracic _______, less effective muscle pump, feedback to ________ ______

arms, muscle, pressure, control center

stroke volume = ___ - ___________ volume minus ___ - ________ volume

end- diastolic, end- systolic

diastole- the _______ phase of the cardiac cycle, between heart beats

resting

systole- the ___________ phase of the cardiac cycle, when the ventricles pump out their stroke volumes

contraction

end- diastolic volume (EDV)- volume of blood in each ventricle at the end of ________, ___ mL in an untrained person at rest

diastole, 120

end- systolic volume (ESV)- the volume of blood that remains in each ventricle after the ventricles have finished ___________, __ mL in an untrained person at rest

contracting, 50

stroke volume = ___mL - __mL = __mL

120, 50, 70

ejection fraction- the __________ of EDV ejected with each contraction

percentage

ejection fraction = ______ ______ / ___ - ___________ _______, 120mL/ 70mL = __%

stroke volume, end- diastolic volume, 58

ejection fraction increases with ________

exercise

stroke volume increases to its highest values during __________ exercise ( __% VO2 max, heart rate: ___ - ___) and remains constant during the progression from ________ to _______ work

submaximal, 40, 110- 120, moderate, maximal

mechanism of increase in stroke volume during exercise: greater systolic emptying = greater ________ ________

ejection fraction

the heart has a functional residual volume- at rest in the upright position, only __ - __% of the blood in the ventricle is pumped out of the ventricle during contraction, __- __mL of blood remains in the ventricle

50-60, 50-80

during graded exercise, the heart progressively increases stroke volume by the means of a more complete emptying during systole- due to effect of ___________ hormones

sympathetic

at rest, __-__% of systemic blood flow goes to the skeletal muscles

15-20

during maximal exercise, __% of the cardiac output can be diverted to the working skeletal muscles

85

increased blood flow to the working muscles is caused by:

1. increased blood ________

2. ________ of arterioles in working muscles due to __________ of the smooth muscle in the walls of arterioles- release of local factors as result of muscle __________

3. ____________ of arterioles in the gut area and non- working muscles- due to ___________ nervous system simulation

pressure, dilation, relaxation, contraction, constriction, sympathetic

poiseuille’s law:

resistance to flow = (_____ __________ x ____ ______) / ______ of ____ ⁴

fluid viscosity, tube length, radius of tube

decreasing the radius by a factor of _ will increase resistance to flow by a factor of __, decreasing the ____ by a factor of 16

2, 16, flow

a __% decrease in the radius of the arterioles will produce a ___% increase in resistance to flow

33, 400

a small change in blood vessel radius will dramatically alter _____ ____

blood flow

the maximum oxygen uptake provides important information on the ________ of the oxygen transport system

capacity

VO2 max provides an integrated measurement of the capacity of ur physiological systems that contribute to: O2 _________ and O2 ___________ while maintaining body homeostasis

transport, utilization

the most important factors that determine VO2 max are:

1. the ability to ventilate the _____ and oxygenate the _____ passing through the lungs

2. the ability of the heart to ____ blood- _______ output

3. the ______ carrying capacity of the blood

4. the ability of the working muscles to accept a large _____ supply

5. the ability of muscle fibers to extract ______ from the capililary blood and use it produce ______- oxidative enzyme levels

lungs, blood, pump, cardiac, oxygen, blood, oxygen energy

as the duration of events requiring heavy continuous energy expenditure becomes progressively greater than one minute, ________ _________ becomes increasingly important as a determining factor for success as aerobic metabolism will contribute to a higher percentage of ___ regeneration

aerobic capacity, ATP

typical values for VO2 max:

1. untrained canadian male (20-29 years)- __ - __

2. untrained canadian female (20-29 years)- __ - __

40-50, 30-40

VO2 max test protocols:

1. the test protocol should exceed _ min, but less than __ min

2. incorporate a ___ __ period, first stage of test

3. the test protocol should be arranged in ______, with each stage progressively increasing in _________ until the termination criteria is reached

6, 15, warm up, stages, intensity

criteria for attainment of VO2 max:

1. the oxygen consumption cease to _______ ________ with increasing work rate and approaches a plateau, the last two values agreeing within +_mL/kg/min

2. heart rate should be close to the ___ - _________ _______ (___- ___)

3. blood lactate levels should be _ milimoles/liter or greater, 2-5 mins post exercise

4. respiratory exchange ratio (____/ ___) should be greater than ____

5. __________ ____________- did the subject look exhausted at the end of the test?

increase linearly, 2, age predicted maximum, 220 - age, 8, VCO2 over VO2, 1.15, subjective observations

in most subjects, the highest VO2 max values can be obtained during uphill _________ running- 5-7% higher than on a _______ ergometer, due to activation of a ______ muscle mass on the treadmill

treadmill, bicycle, larger

however, competitive athletes are able to achieve VO2 max values equal to, or higher than , their _________ scores while doing their own sport, since local muscle capillarization and aerobic enzyme levels are important determinants of ___ ___

treadmill, VO2 max

bicycle ergometer are of two main types:

1. __________- monach ergometers used in BPK labs

2. ____________ ______ bicycle ergometer- resistance is provided by moving a conductor through a magnetic field

mechanical, electrically braked

athletes should ideally be tested in the mode of exercise used in their _____

sport

advantages of bicycle ergometers as compared to treadmills for exercise testing:

1. ____ expensive

2. ________- can be used in field studies

3. don’t require ____________

4. patient is more ______ and body _______ is supported- easier to collect physiological data during exercise- heart rate, blood pressure, oxygen uptake, blood samples…

5. easier to quantify ____ rate

less, portable, electricity, stable, weight, work

disadvantage of bicycle ergometers:

1. cannot obtain as ____ a VO2 max as on the treadmill

2. cycling is not a common mode of movement for most individuals, _______ is a far more common activity

high, walking

based on research studies of identical and fraternal twins, current evidence indicates that VO2 max is 40-50% ___________ determined, improvements in aerobic capacity with training normally range between _ and __%

genetically, 6-20

VO2 max increases with ___ and reaches its peak between __ and __ years of age, then declines approximately ___ percent per year so that by age 55 is it on average 25-30% below values reported for a 20 year old

age, 18, 25 one

before puberty, there is no significant difference in VO2 max between boys and girls. after puberty, the average ____ has a VO2 max that is 20-35% higher than the average female

male

reasons for sex difference:

1. differences in body composition- male has more ________ and less ___, muscle is metabolically a more _______ tissue

2. average male has a 10-14% higher ____________ concentration

muscles, fat, active, hemoglobin

highest reported values for VO2 max:

• male: __ mL/ kg min- cross country skier

• female- __mL/ kg min- cross country skier

94, 77

reasons for the decrease with age:

1. decrease in maximum _____ ____ , _____ ______, and ______ ______ in addition to negative changes in other components of the oxygen uptake and transport systems

2. as individuals grow older, they usually become ____ physically active

heart rate, stroke volume, cardiac output, less

active individuals maintain a considerably higher VO2 max as they ___ as compared to sedentary individuals

age

why use a predictive test?

1. ____ expensive and specialized equipment is required

2. tests can be __________- safety

3. some tests can be administered to _____ groups

4. less __________ is required from the subject

less, submaximal, large, motivation

procedures which use submaximum exercise heart rate to predict VO2 max are based on the following assumptions:

1. ______ relation between heart rate and oxygen uptake- true over a wide range of exercise intensities, but in some subjects at heavy work rates VO2 increases relatively ____ than heart rate

2. _______ maximum heart rate for all subjects- standard deviation is approximately + __ beats/min about the average max heart rate for people of the same age group

   1. maximum heart rate declines with ____, must use an ___ correction factor to estimate maximum heart rate with ___ - age

3. in cases where VO2 is predicted from _____ rate, a fixed ___________ efficiency is assumed

   1. mechanical efficiency may vary by _% on a bicycle ergometer

4. day to day variation in _____ _____- even under highly standardized conditions (environmental temperature, time of the day, diet, drugs…) the variation is about _ beats/min

linear, more, similar, 10, age, age, 220, work, mechanical, 6, heart rate, 5

the VO2 max predicted from submaximal heart rate is generally within __ to __% of the person’s actual value for normal subjects. the type of subject for whom these tests are poor predictors tends to be in the very low or very high VO2 max categories

10-20

error in a well performed direct measurement of VO2 max is + _ - _%

4-5

the efficiency of muscular work is the percentage of ________ energy converted to __________ energy, with the remainder lost as _____

chemical, mechanical, heat

% efficiency = _____ performed (kcal) / _______ expended (kcal) x ___

• the efficiency of large muscle activities such as walking, running and cycling is usually __ - __ %

work, energy, 100, 20-25