control of cardiac output

Question 1

How is cardiac output (CO) calculated?

Answer 1

Heart rate (BPM) x stroke volume (L)

Question 2

what is stroke volume?

Answer 2

volume of blood ejected by each ventricle per beat

Question 3

what’s the units of CO?

Answer 3

L/min

Question 4

do athletes have higher or lower resting CO?

Answer 4

higher

Question 5

do athletes have higher or lower resting CO?

Answer 5

higher

Question 6

why do athletes have higher COs?

Answer 6

reduced heart rate and increased stroke volume

Question 7

do athletes have a heavier or lighter heart mass?

Answer 7

heavier

Question 8

what factors affect Heart Rate (HR)?

Answer 8

autonomic innervation

hormones

Question 9

how is stroke volume calculated?

Answer 9

End diastolic volume (EDV) - end systolic volume (ESV)

Question 10

what’s EDV/ end diastolic volume?

Answer 10

volume of blood in a ventricle at the end of loading or filling (after atria emptying)

Question 11

what’s ESV/ end systolic volume?

Answer 11

volume of blood that remains in the heart after systole

Question 12

define contractility

Answer 12

contractile ability of cardiac muscle at given preload

Question 13

increasing contractility affects stroke volume how?

Answer 13

increases it

Question 14

what’s a positive intropic affect?

Answer 14

when a molecule increases the contractility of the heart

Question 15

what exerts a positive intropic effect on heart?

Answer 15

SNS and adrenaline

Question 16

as well as having a positive intropic effect on the heart, how else does the SNS affect the heart?

Answer 16

increases conduction of cardiac impulse

Question 17

what type of intropic influence does the PNS have on the heart?

Answer 17

negative

Question 18

where does the PNS have a negative intropic influence on the heart?

Answer 18

the vagal nerves only innervate the atria, not the ventricles

Question 19

what is a chronotropic effect?

Answer 19

something that effects heart rate

Question 20

what affects afterload?

Answer 20

vasoconstriction and dilation

Question 21

what’s afterload?

Answer 21

the pressure against the heart must work to eject blood during systole

Question 22

what is blood pressure?

Answer 22

the pressure placed on the walls of vessels by blood

Question 23

what is hypotension?

Answer 23

blood pressure too low

Question 24

what is hypertension?

Answer 24

blood pressure too high

Question 25

what can hypertension lead to and how?

Answer 25

coronary heart disease

Question 26

what is blood pressure determined by?

Answer 26

cardiac output

total peripheral resistance

Question 27

what is total peripheral resistance dependent on?

Answer 27

radius of blood vessels

Question 28

what regulates BP in the short term?

Answer 28

Heart rate, vasoconstriction, vasodilation

Question 29

what regulates BP in the long term?

Answer 29

HR, vasoconstriction and dilation and extracellular volume regulation

Question 30

what’s extracellular volume controlled by?

Answer 30

hormone changes