Perfusion Flashcards
CAD results in impaired blood flow to ________
a. veins
b. brain
c. myocardium
d. toes
c. myocardium
what is the formula used to determine Blood pressure
cardiac output x systemic vascular resistance = blood pressure
define cardiac output
the amount of blood pumped by the heart in 1 minute
define blood pressure
force exerted by the blood against the walls of the blood vessels
how do you determine cardiac output?
heart rate (HR) x stoke volume (SV)
define stroke volume
the volume of blood ejected everytime the heart beats (ml per beat)
define systemic vascular resistance (SVR)
force opposing the movement of blood in the vessels
what determines SVR?
Determined by the radius of arteries and arterioles
* Arteries narrow= SVR
* Arteries dilate=SVR
Regulation of BP is a complex process involving both _________ and _______mechanisms.
short term and long term
short term mechanisms include: SELECT ALL THAT APPLY
a. sympathetic nervous system
b. vascular endothelium
c. renal processes
d. hormonal processes
A and B
the long-term mechanisms include: SELECT ALL THAT APPLY
a. sympathetic nervous system
b. renal processes
c. vascular endothelium
d. hormonal processes
b and d
the renal and hormonal processes regulate ____ resistance and ______
a. venous; blood volume
b. arteriolar; blood volume
c. arteriolar; blood vescocity
d. venous; blood thickness
b
how does angiotensin II act on the heart and blood vessels?
Causes vasoconstriction and tissue growth –> remodeling of vessel walls=primary HTN and atherosclerosis
how do changes in blood volume affect blood pressure?
the higher the blood volume, the greater work is needed for the heart to pump blood through the circulatory system
increased blood volume = increased blood pressure
how does overall compliance affect blood pressure?
the elastic characteristics of the vessels contribute to the overall pressure in the vessels. The more elastic the blood vessels are, the lower the blood pressure.
increased blood vessel elasticity = decreased blood pressure
how does cardiac output affect blood pressure?
related to heart rate and stroke volume
increased HR + Stroke Volume = increased cardiac output = increased BP
how does peripheral resistance affect blood pressure?
the resistance of the arteries is related to the overall compliance characteristics
increased peripheral resistance = decreased overall compliance = increased arterial blood pressure
Normal blood pressure range
systolic: less than 120
and
diastolic: less than 80
elevated blood pressure range
systolic: 120-129
and
diastolic: less than 80
high blood pressure (hypertension) stage 1 range
systolic: 130-139
or
diastolic: 80-89