Cardiac Output
Definition of cardiac output
Cardiac output is the amount of blood pumped by the heart per minute.
Preload
The precontraction pressure in the heart as the volume of blood builds up. @ end diastolic volume
as preload increases, what happens to cardiac muscle fibers
they are stretched
left heart failure
Congestive Heart Failure
Afterload
The force or resistance against which the heart pumps.
Stroke Volume (SV)
The volume of blood pumped forward with each ventricular contraction.
beta blockers
adrenergic antagonists reduce blood pressure heart beats slower w less force
left heart failure results
blood backs up in pulmonary circuit pulmonary congestion(force plasma into tissue of lungs) and edema (swelling)
Right heart failure results
blood backs up into systemic circuit
Medulla oblongata contains what heart rate control centers
cardioaccelerator center cardioinhibitory center
Atherosclerosis
condition in which fatty deposits called plaque (cholesterol) build up on the inner walls of the arteries
as contractility increases, end systolic volume
decreases
eventually, end diastolic volume _______ without adequate ________
decreases, filling time
large afterload causes
difficulty opening semilunar valves keeping these valves open less time to open
low afterload causes
easy opening semilunar valves keeping open is easy more time open
when stretched, what do cardiac muscle fibers do
elastic rebound (exercise helps this) this would decrease end systolic volume
Stroke volume =
end diastolic volume - end systolic volume
Preload increases or decreases
end diastolic volume increases or decreases respectively
Initially, stroke volume remains constant as ______ increases
heart rate
Cardiac Output (CO) =
heart rate (HR) x stroke volume (SV)
Right heart failure process
left ventricle blood - body good right ventricle blood -lungs BAD
in order to increase stroke volume
need to increase difference between end diastolic volume and end systolic volumr
racing heart rate is associated with what body response
pale appearance and fainting (can't properly circulate blood)
chronic hypertension
persistent high blood pressure, over 140/90 mm Hg
left heart failure process
right ventricle good - adequately moves blood to lungs left ventricle fail - cant move blood into body
contractility
strength of ventricular contraction
thus _______ decreases as _______ continues to increase
stroke volume, heart rate
Goals of CO
transportation (nutrients, gas, waste) blood pressure maintenance of body pH (7.4)
End Diastolic Volume (EDV)
volume of blood in each ventricle at end of ventricular diastole right before systole max amount of blood per beat
End Systolic Volume (ESV)
volume of blood remaining in each ventricle after systole minimum amount of blood per beat