Lecture 4: Autonomic Control Of The Heart Flashcards
1
Q
Which autonomic system can enhance heart contractility?
A
Sympathetic
2
Q
At rest is there parasympathetic input to the heart or is it just innate beating?
A
Innate beating gives a heart rate of 100bpm, but at rest it’s lower than that, so there is parasympathetic innervation at rest.
3
Q
How does sympathetic innervation of the heart speed up heart rate?
A
Depolarisation is faster, reaching threshold sooner, resulting in more frequent action potentials, increasing heart rate.
4
Q
What hormone does isoproterenol act like?
A
Adrenaline.
5
Q
What decreases myofilament Ca-sensitivity?
A
Sympathetic stimulation.
6
Q
What is a “funny current” in the heart?
A
Constant leaking in of Na+
