Efferent Autonomic Regulation Flashcards
What is chronotropy?
Modulation of heart rate
What is Inotropy?
Modulation of force of contraction
What is lusitropy?
Modulation of rate of relaxation
What is dromotropy?
Modulation of conduction through AV node
Where can adrenaline and noradrenaline be secreted from?
Chromaffin cells in adrenal gland
What nerve is involved with parasympathetic stimulation of the heart?
Vagus nerve (cranial nerve X)
Where does the vagus nerve originate from in the brain?
Nucleus Ambiguus (NA)
Dorsal Vagal Motor Nucleus (DVMN)
Where does the sympathetic innervation of the spinal cord arise from?
Rostral Ventrolateral Medulla
What receptor does ACh bind to on the spinal cord?
Nicotinic receptors
What is the neurotransmitter involved with the parasympathetic response?
ACh
What does ACh bind to in the cardiac and smooth muscles?
M2 receptors
What is the neurotransmitter involved with the sympathetic response?
Noradrenaline
What receptors does NA bind to in cardiac and smooth muscles?
Alpha adrenoreceptors
Beta 1 adrenoreceptors
What happens to the pacemaker potential during sympathetic stimulation?
Increase in slope -> reaches threshold quicker -> increases HR
What happens to the pacemaker potential during parasympathetic stimulation?
Decrease in slope -> takes longer to reach threshold -> slows down HR
What causes parasympathetic effects to be rapid?
Short signalling cascade
Effect of acetylcholinesterase
What does cAMP affect?
Increases permeability of F-type channels -> causes depolarization
Activates protein kinase A
What does protein kinase A affect?
Increases permeability of L-type Ca2+ channels-> increases pacemaker potential
Activates Kv channels -> commences repolarization
