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