LECTURE 4: Cardiovascular responses to exercise, glycolysis, middle-distance athlete

Question 1

list three purposes of the circulatory system

Answer 1

deliver O2 & nutrition, remove CO2 and waste, regulate body temperature

Question 2

list the two major adjustment of blood flow during exercise

Answer 2

increased CO, redistribution of blood flow

Question 3

when the heart remodels as an exercise response, do the chambers increase or decrease in volume?

Answer 3

increase

Question 4

when the heart remodels as an exercise response, to the cardiac wall increase or decrease in thickness?

Answer 4

increase

Question 5

what is the Morganroth hypothesis?

Answer 5

endurance athletes experience eccentric cardiac remodelling that create large ventricle volumes and relatively low wall thickness, power athletes experience concentric remodelling that create thick ventricle walls and relatively small ventricle volume

Question 6

what is the leading cause of mortality in athletes during sport?

Answer 6

sudden cardiac death

Question 7

at rest, which is longer: diastole or systole

Answer 7

diastole

Question 8

in exercise, which is longer: diastole or systole

Answer 8

neither - same length

Question 9

the length of which of the following is decreased in exercise: diastole or systole?

Answer 9

diastole

Question 10

what causes the first heart sound?

Answer 10

closure of the AV valves

Question 11

what causes the second heart sound?

Answer 11

closure of the semilunar valves

Question 12

what is pulse pressure?

Answer 12

the difference between systolic and diastolic pressure

Question 13

what is mean arterial pressure?

Answer 13

mean pressure in the arteries

Question 14

what is the calculation for mean arterial pressure?

Answer 14

MAP = DBP + 0.33 (SBP - DBP)

Question 15

what blood pressure value is considered hypertensive?

Answer 15

> 140/90mmHg

Question 16

list five factors influencing blood pressure

Answer 16

blood volume, heart rate, stroke volume, blood viscosity, peripheral resistance

Question 17

what is the short term regulator of blood pressure?

Answer 17

SNS

Question 18

what is the long term regulator of blood pressure?

Answer 18

kidneys

Question 19

what is the calculation for cardiac output?

Answer 19

CO = HR x SV

Question 20

what regulatory properties does the PNS have on HR?

Answer 20

slowing HR by inhibiting SA & AV nodes via the vagus nerve

Question 21

what regulatory properties does the SNS have on HR?

Answer 21

speeding up HR by stimulating SA & AV nodes via cardiac accelerator nerves

Question 22

is the SNS stimulation or PNS withdrawal responsible for the initial rise in HR? (~100beats/min)

Answer 22

parasympathetic withdrawal

Question 23

is it more healthy to have a wide heart rate variability (HRV) or low HRV?

Answer 23

wide HRV

Question 24

what do beta-blockers do to heart rate in submax and maximal exerciser?

Answer 24

lowers HR

Question 25

list three factors affecting stroke volume?

Answer 25

Preload/EDV, afterload (average aortic BP or MAP), strength of ventricular contraction

Question 26

describe the frank-starling mechanism

Answer 26

greater EDV results in more forceful ventricular contraction due to greater stretch of ventricle walls

Question 27

list three mechanisms that increase venous return?

Answer 27

venoconstriction (by SNS), skeletal muscle pump, respiratory pump

Question 28

what is the calculation for ejection fraction?

Answer 28

EF% = SV / EDV

Question 29

describe ejection fraction

Answer 29

proportion of blood pumped out of ventricles with each pump

Question 30

what is the average EF% at rest and is it greater or lesser during exercise?

Answer 30

60% at rest, greater in exercise

Question 31

list the three functions of blood

Answer 31

transport gas, nutrients & waste, regulate temperature, buffer & balance acid/base

Question 32

what is the mandated haematocrit cap according to anti-doping authorities?

Answer 32

48%

Question 33

how much does muscle O2 demand increase in exercise from rest?

Answer 33

x15-20

Question 34

at what %VO2max does the increase in SV plateau?

Answer 34

~40%

Question 35

do elite athletes experience an SV plateau at a higher or lower %VO2max?

Answer 35

neither - elite athletes do not experience plateau

Question 36

does HR increase at a linear or non-linear rate as exercise intensity increases?

Answer 36

linear

Question 37

state whether the following increase or not during exercise: systolic BP, diastolic BP, MAP

Answer 37

increase, no increase, increase

Question 38

where is most glycogen stores: the liver or skeletal muscle/

Answer 38

skeletal muscle

Question 39

what is the ATP input requirement for using glucose in glycolysis

Answer 39

2ATP

Question 40

what is the ATP input requirement for using glycogen in glycolysis

Answer 40

3ATP

Question 41

when does glycogenolysis begin in relation to glycolysis?

Answer 41

soon after glycolysis begins and blood glucose has begun to drop

Question 42

what triggers up-regulation of glycolysis?

Answer 42

dropping ATP levels in the cell

Question 43

what triggers down-regulation of glycolysis?

Answer 43

rising levels of ATP in the cell (IE when fat metabolism meets energy demands)

Question 44

what is the main regulatory enzyme of glycolysis?

Answer 44

phosphofruktokinase (PFK-1)

Question 45

what cellular actions inhibit PFK-1 action?

Answer 45

raised ATP, citrate and H+ levels

Question 46

why does citrate presence inhibit PFK-1?

Answer 46

citrate indicates high use of the krebs cycle and FFA to meet ATP demands, reducing the need for glycolysis

Question 47

why do high H+ levels inhibit PFK-1?

Answer 47

H+ is a result of glycolysis, if levels rise too high cellular damage may occur. Thus, PFK-1 is inhibited to lower glycolysis rates

Question 48

what triggers activation of PFK-1?

Answer 48

low ATP, high ADP & AMP

Question 49

what energy system do middle distance athletes use most?

Answer 49

glycolysis

Question 50

do middle distance athletes produce the least or the most lactate?

Answer 50

the most

Question 51

what two systems produce energy in the initial stages of a middle distance event?

Answer 51

ATP-PC system, GLycolysis

Question 52

define oxygen deficit

Answer 52

lag in oxygen uptake at the beginning of exercise

Question 53

will people with higher fitness levels engage aerobic systems earlier or later than people with lower fitness in middle distance events? Why?

Answer 53

faster, means they can reserve their PC and glycogen stores for later

Question 54

describe the rapid portion of the O2 debt

Answer 54

resynthesis of stored PC, replenishing muscle and blood O2, takes up first part of recovery

Question 55

describe the slow portion of the O2 debt

Answer 55

elevated HR & breathing leads to higher energy needs, higher body temperature and catecholamine levels lead to higher metabolic rate, involves conversion of lactic acid to glucose (gluconeogenesis) occurs later in recovery after rapid portion

Question 56

how long does a middle distance event last for?

Answer 56

1-8mins

Question 57

what is the primary cause of exhaustion in 3-7mins of max effort?

Answer 57

accumulation of H+ in the cell

Question 58

do high H+ levels create an acidic environment in the blood or in the cell?

Answer 58

cell

Question 59

what is the resting pH of blood

Answer 59

7.40

Question 60

do high lactate levels cause acidity of the blood or cells?

Answer 60

blood

Question 61

what happens to 'recycled' lactate?

Answer 61

some taken by liver and undergoes gluconeogenesis, some taken by heart & muscles and converted to pyruvate for other biomechanical processes

Question 62

how is H+ cleared from the body after exercise?

Answer 62

reacts with bicarbonate in blood to be neutralised