Lecture 5 Flashcards
What kind of blood pressure is measured typically?
Arterial blood pressure
What determines blood pressure of an artery?
Amount of blood (CO,
Diameter of blood vessels
What determines pulse pressure?
compliance of the artery
Reflective waves
Stroke volume
What is mean arterial pressure?
diastolic BP + 1/3 pulse pressure
Mean arterial pressure is the mean pressure of a blood pressure wave.
What happens to blood pressure when standing?
Pulse pressure decreases due to the increase in diastolic BP.
Systolic blood pressure decreases due to decrease in stroke volume caused by pooling of blood in legs.
Diastolic BP increases due to increase in TPR.
How much blood goes to the legs and doesn’t come back up to the chest?
about half a liter
Where are the body’s baroreceptors located?
In the common carotid artery and the aorta
How does the baroreceptor increase TPR?
baroreceptor stimulates the sympathetic nervous system via the brain this increases TPR
What happens milliseconds after standing?
There is a massive drop in BP caused by drop in stroke volume. Heart rate increases significantly when standing up actively. When passively held up this doesn’t happen.
Initially there is a drop in TPR. (Reason to be learned in assignment)
What happens when standing to blood pressure?
systolic doesn’t increase much
diastolic pressure increases
pulse pressure decreases as a result.
What things determine pulse pressure?
Syst - diast
Stroke volume
arterial compliance
reflected waves
How can MAP be approximated?
PP/3 + DBP
Where are baroreceptors located??
aorta and carotid contain the baroreceptors.
What happens to baroreceptor firing in response to blood pressure increase?
baroreceptor firind decreases when blood pressure increases.
What is the brain’s response to an increase in BP?
sympathetic nervous system is activated causing HR increase, TPR increase, and MAP increase
