Autonomic Regulation of the Heart - Quiz 1 Flashcards
(35 cards)
role of SA node on actions on the heart
- changes nodal action potential
- changes heart rate
parasympathetic role on heart rate
- decreases heart rate
sympathetic role on heart rate
- increases heart rate
sympathetic role on contractility
- increases contractility
sympathetic role on vasculature
- constricts smooth muscle of blood vessels
autonomic role of baroreceptor reflex
- regulates autonomic response to changes in pressure and volume in the vasculature
NE or EPI binds to
- beta1 adrenergic receptors on SA nodal cells
beta receptors on SA nodal cells have what kind of receptor
- G protein coupled receptor
NE or EPI binding to B1 adrenergic receptor causes what?
- increases open state probability of HCN (mostly Na+) - due to cAMP
- increases opening of T type Ca channels - due to more negative membrane potential
- increases opening of L-type Ca channels - due to cAMP -> PKA which opens DHP
opening of HCN and T-type Ca channels causes
- faster rate of phase 4 depolarization
- major effect
opening of L-type Ca channels causes
- less positive threshold
additional sympathetic effect of NE or EPI binding to B1 adrenergic receptor
- increased conduction velocity of action potentials
- increased heart rate
increased conduction velocity of action potentials is what kind of effect
- positive dromotropic
increased heart rate is what kind of effect
- positive chronotropic
parasympathetic effect Ach binds to
- muscarinic receptors
what type of receptor are muscarinic receptors
- G coupled protein receptors
results of Ach binding to muscarinic receptor
- increases permeability to K+
result of increased permeability to K+
- hyper polarization maximum diastolic polarization more negative
- slows depolarization
additional parasympathetic effect of Ach binding to muscarinic receptor
- decreased conduction velocity
- decreased heart rate
decreased conduction velocity is what kind of effect
- negative dromotropic
decreased heart rate is what kind of effect
- negative chronotropic
sympathetic stimulation effects on cardiac muscle contractility
- increased tension developed
- increased rate of tension increase
- increased rate of relaxation
sympathetic stimulation effects on cardiac muscle contractility a result of
- L-type channels increasing permeability to Ca2+
- increasing activity of Ca2+ pumps to make myocyte ready for next depolarization and increase amount of Ca2+ in stores for next release burst
where are the baroreceptor sensory receptors located?
- aortic arch
- carotid sinus
