CVS reflexes Flashcards
where are the arterial baroreceptors found
carotid sinus
aortic arch
what does loading mean
effect of increase in BP on baroreflexe.g. stress
4 effects of the depressor response
BP falls
bradycardia
vasodilatation
pulse pressure falls
what is unloading
effect of decreased BP on the baroreflex e.g. in hamorrhage
4 effects of the pressor reflex
adrenaline secretion
vasopressin secretion
stimulation of RAAS
vasoconstriction
3 types of cardiac receptors
nociceptive sympathetic afferents
veno-atrial mechanoreceptors
ventricular mechanoreceptors
what is the nociceptive sympa afferents stimulated by
K+/H+ produced during ischaemia
what does the nociecptice sympa afferents cause
angina
what is the venoatrial mechanoreceptors stimulated by
overdistension of atria
what are the two parts to the veno-atrial mechanoreceptor reflex
initial pressor reflex(inc HR)
long term depressor reflex(inc diuresis)
what are ventricular mechanoreceptors stimulated by
over distension of ventricles
what does the ventricular mechanoreceptors cause
sends cardiac vagal afferents to NTS which initiates a depressor response
override hearts response
where are muscle metaboreceptors found
skeletal muscle
what metabolites are released during exercise
ATP
K+
lactate
adenosine
what are muscle metaboreceptors activated by
metabolites released during exercise
what does the activated metaboreceptors initiate
pressor reflex
what does local anaesthetic do
blocks metaboreceptors afferent fibres
prevents pressor receptors
what does NTS send impulses to
CVLM
what does CVLM do
inhibit RVLM
what does RVLM do
inc sympa
what do baroreceptors do when they sense a rise in BP
increase impulses to NTS
what doe baroreceptors do when they sense a decrease in BP
decrease impulses sent to NTS
what happens when baroreceptors innervated by parasympathetics sense a rise in BP
afferents to NTS
NTS stimulates nucleus ambiguus
vagal to SAN
bradycardia
what is fainting also called
vaso-vagal attack
what is fainting initiated by
emotion stimulating parasympathetics to the heart
