Control Of Cardiac Output Flashcards
Define afterload.
The load the heart must eject blood against.
Define preload.
Amount the ventricles are stretched in diastole.
Define central venous pressure.
The pressure in the large veins draining into the heart.
What is arterial pressure.
Pressure in the large arteries.
Define total peripheral resistance.
Resistance to blood flow offered by all the systemic vasculature.
What happens to pressure of a fluid in a tube as it encounters resistance.
Pressure that the blood exerts drops. Constriction of arterioles increases the resistance, pressure in capillaries and venous side falls, pressure on the arterial side rises.
What happens in TPR falls and CO is unchanged.
Arterial pressure will fall and venous pressure will increase.
What happens if TPR increases and CO is unchanged?
Arterial pressure will increase and venous pressure will fall.
What happens if CO increases and TPR is unchanged?
Arterial pressure will rise, venous pressure will fall.
What happens if CO decreases and TPR is unchanged?
Arterial pressure will fall, venous pressure will rise.
What are the cardiac output and stroke volume equations?
Cardiac output= stroke volume x heart rate. Stroke volume= end diastolic volume - end systolic volume.
Describe ventricular filling.
Happens during diastole, AV valves are open but the aortic and pulmonic valves are closed.
What are factors determining cardiac output?
How hard it contracts, how hard it is to eject blood.
