Autonomic control of the CVS system Flashcards
receptors in the heart and vessels, nerves, chemoreceptors, baroreceptors, respiratory and cardiovascular centres
Which receptors receive sympathetic innervation in the heart
B1 (the main one - 1 heart)
B2
a1
(All adrenergic receptors)
Neurotransmitter which binds receptors for sympathetic innervation in the heart
NA
Neurotransmitter which binds receptors for parasympathetic innervation in the heart
Ach
Receptors receiving parasympathetic innervation in the heart
M2 (muscarinic Ach)
Effect of sympathetic innervation of the heart
Increased: HR, contractility, ionotropy…
Effect of parasympathetic innervation of the heart
Decreased: HR, contractility, ionotropy…
Which branch of the autonomic nervous system innervates the blood vessels
sympathetic only (controlled by the vasomotor centre in the medulla) causes vasoconstriction
receptors involved in sympathetic innervation of the coronary arteries
a1-adrenoreceptors
receptors involved in parasympathetic innervation of the coronary arteries
M3-cholinergic receptors
What overrides sympathetic and parasympathetic innervation of the coronary arteries?
vasoconstrictor and vasodilator metabolites coming from the myocardium
Where does the parasympathetic nerve (vagus) which stimulates the heart originate in the brain?
nucleus ambiguus (medulla)
Where do the sympathetic nerves which stimulate the heart and vessels originate in the brain?
rostral ventrolateral medulla (RVLM)
How does parasympathetic innervation of the heart (Ach binding M2 receptors) effect the ion channels and pacemaker potential at the SA node?
Opens K channels hyperpolarising the cell
reduces the slope of the pacemaker potential
How does sympathetic innervation of the heart (NA binding B1 receptors) effect the ion channels and pacemaker potential at the SA node?
Opens Na and Ca channels
Increases the slope of the pacemaker potential
What sympathetic adrenergic receptors are on ALL blood vessels?
a-1 - vasodilation
