Excitation-contraction coupling in cardiac muscle Flashcards
(19 cards)
what is the regulatory protein on actin filaments?
1-2
troponin C
what does “sarco” basically mean?
1- 3
muscle
what is the sarcoplasm?
1-3
cytoplasm of cardiac muscle cells
when resting, how much calcium ions do we release?
1-3
2uM
give examples of typed of drug that would clam down the heart?
1-3
- calcium channel blockers
- beta blockers
what does the word “inotropic” mean?
1-5
strengthening - contract harder
what type of substance are adrenalin and noradrenaline?
1-5
catecholamines
what are the three mechanisms for regulating force?
1-5
- size of calcium ion current
- affinity of contractile proteins for calcium ions
- actin-myosin overlap
a cheap drug that can take the strain off the heart?
1-5
propranolol
How many discharges does the sinoatrial node produce?
1-6
1 per second (just under a second)
where are pacemaker cells found?
1-8
SA node
is is the SA node always ready to fire (unstable)
1-8
pacemaker cells in the SA node have leaky sodium channels. (sodium goes into cell)
what is the chronotropic effect?
1-10
increase in rate of pacemaker potential - more heart rate (increase speed)ff
what is the main parasympathetic nerve to the heart?
1-12
vagus (cranial nerve 10)
what do the parasympathetic nerves release?
1-12
acetylcholine
what does bradycardia mean?
1-12
slowing down in heart rate
what does tachycardia mean?
1-12
a fast heart rate
what is hyperkalaemia?
1-16
excess potassium ions in the bloodstream
what happens when someone has hyperkalaemia?
1-16
heart rate can get out of control and cause ventricular fibrillation
