Blood Pressure Flashcards
what is blood pressure?
force exerted by blood against inner walls of blood vessels
where is blood pressure lowest?
veins
Blood pressure usually refers to the pressure in this specific blood vessel
artery
the maximum blood pressure reached during ventricular contraction is called
systolic pressure
the minimum blood pressure reached during ventricular relaxation is called
diastolic pressure
numbers in a blood pressure reading are the ___ pressure over the ___ pressure
systolic; diastolic
instrument that measures blood pressure
sphygmomanometer
the expansion and recoil of arteries is called a
pulse
two common pulse points
radial and carotid arteries
Four factors that are directly related to BP
- cardiac output
- blood volume
- peripheral resistance
- blood viscosity
cardiac volume =
stroke volume * heart rate
amount of blood discharged from each contraction
stroke volume
what are two factors that would lower blood volume?
hemorrhage or dehydration
friction between blood and walls of blood vessels is called
peripheral resistance
peripheral resistance ___ blood flow, which means BP ____ it
hinders; fights
difficulty in which molecules flow past each other
blood viscosity
formula for blood pressure
cardiac output * peripheral resistance
what two things does the body adjust in order to adjust blood pressure
cardiac output and peripheral resistance
where are main baroreceptors locatated?
aortic arch and carotid arteries
what are the 4 steps in the cardioinhibitory reflex?
- baroreceptors sense BP increase
- baroreceptors send impulses to medulla oblongata
- MO sends parasympathetic impulses to SA node to slow
- results in decrease in CO
what are the 4 steps in the cardioaccelerator reflex?
- baroreceptors sense BP decrease
- BR send info to medulla oblongata
- MO sends sympathetic impulses to increase heart rate
- increases CO
peripheral resistance goes up with ____ and down with ___
vasoconstriction; vasodilation
what are three things that can cause a change in peripheral resistance?
- sympathetic impulses - vasomotor center in medulla oblongata
- gasses - CO2, decreased O2 and ph
- hormones - epinephrine and norepinephrine cause vasoconstriction