Week 4 - Cardiovascular System and Exercise Flashcards
what is stroke volume?
the amount of blood ejected from ventricle during each heart beat
what is the average SV?
60-100ml
what is the cardiac output?
heart rate x stroke volume (HRXSV)
What is the average cardiac output?
5 litres per minute
what happens CO during exercise?
it increases
how much blood is circulated at rest?
10 litres, twice our blood volume
what is CO when SV= 70ml and HR=70bpm?
4900ml ~ 4.9L
What happens SV during exercise?
it increases slowly up until 150 watts and then decreases
what happens HR during exercise?
it increases proportionally with work load up until 200 watts
what happens CO during exercise?
it increases at a fast rate proportionally to work load increase - we need more oxygen and more blood flow to collect CO2
what drives CO?
SV and HR
what drives CO in light exercise?
HR and SV
what drives CO in strenuous exercise?
HR alone
what 3 key physiological variables within cardiovascular system that change with exercise?
SV, HR and CO
what controls where and when blood flows?
vas constriction and dilation
why at rest does kidneys get alot of blood flow?
they filter blood
where does blood flow go when exercising?
skeletal muscle is prioritised
why does total peripheral resistance TPR change during strenuous exercise?
more dilation than constriction
what is TPR?
the overall resistance to blood flow
does blood flow in brain change?
no
what happens CO in resistance exercise?
it increases much slower than aerobic exercise
what happens TPR during resistance exercise?
there is no major vasdialation compared to aerobic exercise, therefore no change occurs
what happens blood pressure during resistance exercise?
it increases faster than it does for aerobic
what happens the CVS during resistance training continuously?
heart increases in muscle size
skeletal muscles increase
resistance to fatigue
what is hypertrophy?
muscle growth
what happens the CVS in aerobic training?
size of chambers increase, thickness does not
resting heart rate decreases
SV increases
blood volume increases
why does heart change shape in response to exercise?
it is a physiological response to attempt to maintain homeostasis and increase efficiency
how does space effect heart shape?
muscle mass decreases
it becomes spherical and less efficient due to lack of gravity
what are CVS variables in elite althetes at rest?
low HR and high SV at rest
what is systolic pressure?
highest pressure in artery
what is diastolic pressure?
lowest pressure in artery
what is arterial measured in?
mm/Hg
what causes increase in BP?
stress, no exercise, fatty diet, salty diet, smoking
how do we recognise hypertension?
systolic pressure>130mmHg
diastolic pressure<90mmHg
how do we get rid of hypertension?
reduce blood volume and cardiac output
what do beta blockers do?
reduce CO
what do alpha blockers do?
reduce TPR
what is the leading cause of death?
CDV - cardiovascular disease
benefits of exercise for CVS?
decreases BP
decreases fat in blood
decreases bad cholesterol LDL
hardens arteries - strengthens them
maintains heart muscle
