Regulation of stroke volume and heart rate Flashcards
Where is adrenaline released from?
Adrenal medulla
Where is noradrenaline released from?
Sympathetic fibre
What receptors does adrenaline and noradrenaline bind to on the sinoatrial node?
beta 1 receptors
What receptors does acetylcholine act on on the sinoatrial node?
Muscarinic receptors
What is starlings law?
The energy of contraction is proportional to the initial length of the cardiac muscle fibre
In the regulation of stroke volume, what determines preload?
End diastolic volume, capacitance vessels
In the regulation of stroke volume, what determines afterload?
Total peripheral resistance (arterioles, resistance vessels)
What affect does the sympathetic and parasympathetic nervous system have on stroke volume?
Sympathetic - increases contractility give stronger but shorter contractions, increasing stroke volume
Parasympathetic - little effect
What determines cardiac output?
CO = HR x SV
