blood pressure Flashcards
how can you increase systolic blood pressure?
increase stroke volume and decreasing aortic elasticity
why does the decrease in aortic elasticity lead to high systolic BP?
less aortic elasticity means less dampening of the rise in pressure from VC
how would you increase diastolic blood pressure?
increase the total peripheral resistance and increasing aortic elasticity and decreasing heart rate.
why does a decrease in aortic elasticity decrease the DBP?
there will be less elastic recoil to support the DBP
how do you calculate mean arterial blood pressure.
CO * total peripheral resistance
how is the control of arterial blood pressure achieved?
using pressure sensors which are in the circulation and integration centres in the CNS, and the autonomic NS effectors.
where are the high pressure baroreceptors?
carotid arteries and aortic arch.
what is the transmural pressure?
the pressure difference between the outside ad inside of the blood vessel wall
what happens when the high pressure baroreceptors detect an increase in transmural pressure?
there is an increase in afferent nerve discharge. (from eh carotid sinus and aortic nerves, vagus etc)
where are the low pressure baroreceptors?
also called volume receptors
located in pulmonary vasculature and ventricular walls.
how does the integration centres of the medulla, control blood pressure?
when the baroreceptors detect high pressure, they increase discharge from carotid sinus, vagus, aortic nerves etc. this stimulates the NTS (nucleus of tracts solitarius)
what happens when the arterial blood pressure decreases.
a decrease in BP> decrease I baroreceptor discharge> decrease in pressor area inhibition> decrease in depressor area activation> increase in SNS activity> increase heart rate and peripheral resistance
this increase BP back to normal
what happens when arterial blood pressure increases?
arterial BP increase > increase in baroreceptor discharge > increased inhibition of pressor area> increased activation of depressor area > decrease in SNS activity > decrease in heart rate and peripheral resistance
blood pressure goes down
what is the difference between DBP and SBP?
the blood pressure is measured by the pressure on the blood vessel walls by the blood.
SBP is the pressure during ventral contraction
DBP is the pressure during the rest in between beats.
