Cardiovascular: regulating blood pressure and baroreceptors Flashcards
mean arterial pressure (MAP) is important in causing tissue perfusion and creating pressure gradients. eg for brain, when upright, blood pressure in brain is ??? than other sites
lower
Central Venous Pressure (CVP) refers to pressure at ??? near right atrium
vena cava
MAP must be maintained to ensure all tissue are ???
perfused
TRUE or FALSE: the CV system allows flexibility for distributing blood flow, mostly by controlling systemic MAP, therefore change in flow of one bed doesn’t dramatically change other vascular beds
TRUE
because CV system allows flexibility of blood flow distribution, changes in one vascular bed doesn’t or does dramatically change other vascular beds?
DOESN’T change dramatically
we have a MAP at a high enough level to ensure brain perfusion when standing, very high vascular resistance in ??? and high pressure of MAP needed for glomerular filtration
high vascular resistance in the eye
CVP is important for the pressure inside the large systemic veins leading to the right or left side of the heart? this is due to atrial filling
right side of heart
CVP affects atrial filling ??? which determines intrinsic contractility
atrial filling pressure
High pressure Baroreceptors are found in the arterial or venous systems?
arterial systems, especially carotid sinus and aortic arch
low pressure Baroreceptors are found in the venous or arterial system as well as the heart?
venous system and heart
Which baroreceptor type focuses on MAP regulation?
High pressure baroreceptors
which type of baroreceptor focuses on volume regulation and cardiac filling? (THINK CV)
low pressure baroreceptors
baroreceptors in the Carotid Sinus refers to the distensible portion of the internal carotid ???
carotid artery
aortic arch is highly compliant and distends with each left or right ventricular ejection?
LEFT
baroreceptors are ???-sensitive: the ??? of a vessel distorts the receptor causing afferent nerve impulse via CN IX and CN X
baroreceptors are STRETCH-sensitive, the stretch of a vessel distorts
high pressure baroreceptors are located in highly ??? vessels and the receptors are bare nerves
compliant/distensible
receptor potential for HP Baroreceptors: input activates the receptor, which activates ion channels and triggers a current = membrane ??? in sensory afferent nerve fibres
membrane depolarisation
increased pressure = increased stretch = increased receptor potential for high or low pressure baroreceptors?
high pressure baroreceptors
increased stretch = increased receptor potential, causing inward current to repolarise or depolarise the nerve membrane?
depolarise
a biphasic response (HPB) is the large ??? depolarisation (dynamic overshoot) which then settles into a modest steady state component of receptor potential
large initial depolarisation
a Graded response (HPB) is the amplitude and ??? proportional to stretch input
frequency
TRUE or FALSE a graded response is unlike ‘normal’ action potentials where amplitude = all or nothing as it can mean nothing.
TRUE
during exercise high pressure baroreceptor sensitivity increases or decreases in proportion to intensity of exercise?
decreases
TRUE or FALSE: HP baroreceptors can reset after several days which is useful because they can become desensitised if overworked
TRUE
