week 9

Question 1

what is stroke volume

Answer 1

the amount of blood pumped by the left or right ventricle per beat (ml)

Question 2

what is cardiac output (Q)

Answer 2

the amount of blood pumped by left or right ventricle per minute (l/min)

Question 3

both the left and right ventricles must have the _______ cardiac output

Answer 3

same

Question 4

cardiac output formula =

Answer 4

heart rate x stroke volume

Question 5

what happens when the cardiac output increases in excersise?

Answer 5

more oxygen is transported to the working muscles

Question 6

what does the Fick equation represent

Answer 6

the VO2 - how much oxyegn is utilized by tissues in the body

Question 7

what is a-vO2 diff

Answer 7

arterial-mixed venous oxygen difference
how much oxygen is extracted at the tissue capillary beds

Question 8

how do you increase oxygen uptake

Answer 8

by increasing the cardiac output

Question 9

the cardiac output required for a workload is _________ for trained and untrained subjects

Answer 9

similar

Question 10

what increases linearly with work rate and 02 consumption

Answer 10

heart rate

Question 11

for any workload trained subjects will have a lower________?

Answer 11

heart rate

Question 12

trained subjects have a higher ____________ than untrained subjects causing lower _________ than untrained for a work load VO2

Answer 12

heart rate
stroke volume

Question 13

which has the higher oxygen uptake? Arm excersises or leg?

Answer 13

arms

Question 14

formula for stroke volume

Answer 14

end-diastolic volume minus end systolic volume

Question 15

what is diastole

Answer 15

the resting phase of the cardiac cycle, (between heart beats)

Question 16

what is systole

Answer 16

the contraction phase of the cardiac cycle (when the ventricles pump out their stroke volume)

Question 17

what is end-diastolic volume (EDV)

Answer 17

the volume of blood in each ventricle at the end of diastole
- generally 120

Question 18

what is end-systolic volume esv

Answer 18

the volume of blood that remains in each ventricle after the ventricles have finished contracting
- generally 50

Question 19

what is the ejection fraction

Answer 19

the percentage of EDV (end-diastolic volume) edjected with each contraction

Question 20

what is the formula for ejection fraction

Answer 20

stroke volume divided by edv

Question 21

when does the stroke volume plateaus

Answer 21

at 40% vo2 max, prior it rises iwth excersise

Question 22

what is ment by the hearts functional residual volume

Answer 22

the volume of blood left in the heart as only 50-60% of blood in the ventricle is pumped out during contraction

Question 23

during excersise how does the heart progressively increase stroke volume

Answer 23

by more complete emptying of ventricles duirng systole by sympathetic hormones

Question 24

what is the difference in blood flow to skeletal muscles at rest vs when working

Answer 24

• at rest 15-20% of blood flow
• working 85% of blood flow

Question 25

what causes the increased blood flow to muscles during excersise (3)

Answer 25

1. increased blood pressure 2. dilation of arterioles in muscles becuase the smooth muscle relaxes in the walls of arterioles 3. constrictions of arterioles in the gut and non working muslces

Question 26

how do the arterioles dilate in working muscles

Answer 26

by the smooth muslces in the walls of the arterioles relaxing

Question 27

what does poiseuilles law determine

Answer 27

the resistance to flow

Question 28

what can alter blood flow the most

Answer 28

a change in the blood vessel radius (radius of tube)

Question 29

what is our maximal aerobic power (VO2 max)

Answer 29

our maximal capacity to utilize oxygen per minute

Question 30

factors that determine a persons vo2 max (5)

Answer 30

1. ability to ventilate lungs and o2 blood to pass through the lungs 2. ability of cardiac output(hearts ability to pump blood ) 3. the oxygen carrying capacity of the blood 4. ability of muscles to accept large blood supply 5. ability of muscle fibers to extract o2 and use it to produce energy (ATP)

Question 31

aerobic metabolism will contribute to a higher percentage of _____________

Answer 31

ATP regeneration

Question 32

V02 max will be ___________ for trained subjects

Answer 32

higher

Question 33

what are the 3 v02 test protocols

Answer 33

1. should exceed 6 min but be less than 15 2. there should be a warmup period 3. arranged in stages with each stage progressively increasing

Question 34

5 criteria for attainment of VO2 max

Answer 34

1. oxygen consumption approaches a plateau with increasing work rate 2. Heart rate should be close to age predicted max 3. blood lactate levels should be 8 millimoles/liter or greater, 3-5 min post excersise 4. VOC2 divided by VO2 (respiratory exchange ratio) should be greater than 1.15 5. does subject look exhausted at end of test

Question 35

atheletes are able to achieve higher vo2 max when _________

Answer 35

playing their sport

Question 36

what is a ergometer

Answer 36

the bicyle test for Vo2 max

Question 37

advantages of bicycle ergometers compared to treadmills

Answer 37

1. less expensive 2. portable 3. no electricty 4. patient more stable and supported 5. easier to quantify work rate

Question 38

disadvantages of bicyle ergometers

Answer 38

1. can't obtain as high a Vo2 max as on a treadmill 2. cycling is not a common mode of movement for most indviduals

Question 39

what is the heredity of V02 max and how much can training change it

Answer 39

40-5-% genertically determined 6-20% can be changed

Question 40

what age does vo2 max peak

Answer 40

18-20

Question 41

is there a sex difference in v02 max abilities

Answer 41

yes males after puberty have a vo2 max that is 20-25% GREATER

Question 42

why do males have higher vo2 max ability

Answer 42

- more muscle less fat - males have higher hemogloblin concentration

Question 43

how does vo2 decrease with age

Answer 43

by 1 percent each year

Question 44

why does vo2 decrease with age (2)

Answer 44

1. decrease in max hr, stroke volume and cardiac output 2. individuals become less phsyically active

Question 45

why do we use the predictive v02 max test

Answer 45

1, less expensive 2. tests can be submaximal (safe) 3. can be administered to large groups 4. less motivation needed from subject

Question 46

what are the 4 assumptions that allow us to use submaxiumal excersise heart rate to predict V02 max

Answer 46

1. linear relation between HR and oxygen uptake 2. similar max heart rate for all subjects of the same age 3. a fixed mechanical efficiency is assumed 4. variation in heart rate is approx +- 5 beats/min

Question 47

formula to estimate max hr with age

Answer 47

220 - age

Question 48

what is the efficiency of musclular work

Answer 48

the percentage of chemical energy converted to mechanical, remainder lost to heat

Question 49

what is the formla for mechanical efficfiency

Answer 49

%eff = (work performed (kcal) divided by energy expended (kcal)) x 100