Cardiac Ex phys

CO

Cardiac output: the total volume of blood your heart pumps through your body every minute

SV

Stroke Volume: amount of blood pumped by the heart with each heart beat

HR

Heart Rate: the speed at which your heart beats

TPR

Total peripheral resistance: the resistance blood must overcome to move through the body's circulatory system

EDV

End diastolic volume: the total amount of blood in the heart's ventricle right before it contracts

ESV

End systolic volume: the amount of blood left in the heart's ventricle right after it finishes squeezing

VR

Venus return: the flow of blood from the body back to the right atrium of the heart

MAP

Mean arterial pressure: the average blood pressure in a person's blood vessels during one complete heartbeat

SBP

Systolic blood pressure: (top number) the force and pressure of blood pushing against your artery walls when your heart beats and actively pumps blood out

DBP

Diastolic blood pressure: (bottom number) measures the force of blood pushing against your artery walls when your heart muscle rests between beats

EF

Ejection fraction: the percentage of blood pumped out of your heart's main pumping chamber (the left ventricle) with each heartbeat

Equation making up CO

HR x SV

what makes up SV?

EDV - ESV

Main goal of CO

to pump enough blood each minute to deliver vital oxygen and nutrients to the brain, muscles, and other organs while removing waste products

What effects SV?

Exercise, blood flow, blood volume, muscle function, hormones, nervous systems

What effects HR?

intrinsic controls, hormones, nervous system

What is the parasympathetic nervous system?

rest and digest

What is the sympathetic nervous system?

fight or flight

What are arterial baroreceptors?

located in the walls of carotid sinus and aortic arch, sense the level of arterial pressure, and changes level of activity in response to changes in arterial pressure. Short-term control

How to control the heart

central command, arterial baroreceptors, muscle metaboreceptors,

what is central command?

it is a feed forward system. increases heart rate and blood pressure at the start of exercise, decreasing parasympathetic activity

Muscle Metaboreceptors

sensory nerve endings in skeletal muscles that respond to chemical changes during contraction, increase sympathetic activity and arterial pressure.

What is preload?

the amount of blood in the ventricle prior to contraction. More tension, more forceful contraction

If you increase preload…

increase SV and CO, more volume of blood

what is afterload?

The resistance the heart must overcome in order to eject blood into systemic circulation

How much does blood volume increase under chronic training?

15-20%

Blood volume refers to changes in…

hematocrit / plasma

What is hematocrit?

the percentage of your total blood volume that is made up of red blood cells

When you increase blood volume…

you increase VR, increasing preload, increasing SV, increase CO

What is hypovolemia?

too little blood volume

What is hypervolemia?

too much blood volume

What is the first to increase in response to exercise?

plasma volume

What is the hearts response to exercise?

increase heart rate, sympathetic takes over, catecholamines will increase with intensity

what are catecholamines?

trigger sympathetic nervous system. Epinephrine and norepinephrine. the release of these increase with intensity

Why does the line drop at 160 bpm?

As cardiac output is increased and HR is increased, there is not enough time in between beats to fill the left ventricle