BY 409L Module 7

Three factors that affect blood pressure are...

- cardiac output

- peripheral resistance

- blood volume

cardiac output

the volume of blood leaving the ventricle per minute

Cardiac output is calculated by...

stroke volume x heart rate

vasoconstriction

the decrease in diameter of an artery which causes more resistance which increases pressure

vasodilation

the increase in diameter of an artery which reduces resistance which decreases pressure

More viscous blood has more...

cells

The more cells means ________ blood, which increases resistance.

thicker

blood volume

-fluid balance between what two things?

fluid balance between interstitial fluid and blood or blood loss through injury

True or false: Swelling or bleeding can increase blood volume.

False - decrease

baroreceptors

-where?

-detect what?

mechanoreceptors in the carotid and aorta that detect changes in blood pressure

Measuring the stretch of an artery is an ________ measurement.

indirect

atherosclerosis

-build up of? in the?

-which causes?

-therefore receptors are not?

-the brain interprets bp to be lower or higher?

-what does it do to compensate?

the build-up of plaque in the arteries which causes arteries to not stretch as easily, therefore receptors are not triggered, and the brain interprets blood pressure to be lower than it actually is and increases to compensate

baroreceptor reflex

keeps your blood pressure steady when you experience something that raises or lowers it

If pressure drops, then the artery stretches less, which causes blood pressure to __________________.

increase

If pressure increases, then the artery stretches more, which causes blood pressure to ____________________.

decrease

Mean Arterial Pressure (MAP)

the average of pressure in the system across one cardiac cycle

Mean arterial pressure is caused by... (2)

cardiac output and total peripheral resistance

Mean arterial pressure is calculated by...

diastolic pressure + 1/3 pulse pressure

True or false: Normal blood flow makes no noise.

True

Korotkoff sounds

used in manual measurement of blood pressure where the inflated cuff collapses an artery and stops blood flow which causes blood flow to be turbulent and noisy