Cardiovascular and respiratory Flashcards
pulmonary circuit
heart and lungs
circulation of the blood, pulmonary a
to lungs
and pulmonary veins
back to heart
systemic circuit
heart and body
circulation of blood, aorta
to body
vena cava
back to heart
heart = MYOGENIC
generates its own electrical impulse
causes the cardiac muscle to contract
conduction system
SA
AV
bundle of his
bundle branches
purkinje fibres
diastole
relaxation phase
heart fills with blood - passively
systole
contraction phase
blood forcible ejected - aorta and pulmonary artery
atrial
ventricular
HR
typical value
number of time a heart beats per minute
72 bpm
SV
typical value
amount of blood ejected from LV per beat
70 ml
Q
typical value
amount of blood ejected from LV in one minute
5l/min
magic equation - heart
HR x SV = Q
brady cardia
heart rate below 60 bpm
maximum HR
220-age = HR max (bpm)
HR of untrained (rest)
70-72 bpm
HR of trained (rest)
50 bpm
SV of trained (rest)
50 ml
SV untrained (rest)
70 ml
Q trained (rest)
5l/min
Q untrained (rest)
5l/min
HR in response to exercise
increases in proportion to intensity until max HR is reached
SV response to exercise
increased in proportion to exercise until plateau is reached
at 40-60% of working capacity
why does SV increase
venous return
frank starlings law
venous return
return of blood to the RA through the veins
frank starlings law
increase VR = increase SV
= increase stretch in ventricular walls
= increased force of contraction
