Heart receptors Flashcards
which receptors are innervated sympathetically
B1 receptors
which receptors are innervated parasympathetically
M2 receptors
B1 receptors are innervated by
adrenaline/ noradrenaline release
which tissue is B1 receptors found in
San, atria, ventricles
what effect will innervated B1 receptors have on the heart
- increased heart rate
- increased contractility
- increased relaxation speed
- more action potential
- increased CO
- increase in blood pressure
what effect will innervated M2 receptors have on the heart
- decreased heart rate
- decreased contractility
- decreased relaxation speed
- decreased CO
- decreased BP
outline the b1 receptor cascade
1) adrenaline will bind to B1 receptor and Gs cascades will commence
2) Adenylyl cyclase will activate cAMP
3) cAmp activates PKA which causes two repsonsed
3) phosphorylates Ca2+ channels and causes calcium influx
4) calcium influx from the SR
5) increasing calcium conc= more contraction possible
outline M2 receptor cascade
1) Ach binds to M2
2) activates Gi
3) no conversion ATP to cAMP by adenylyl cyclase
4) less PKA
5) less calcium
6) less contraction
Q1) A 56-year old hypertensive patient presents to theQ1) A 56-year old hypertensive patient presents to the A&E with tetanic contractions and the doctor prescribes a different drug since beta1-blockers do not seem to be working. What is the likely drug prescribed?
a) Beta2-blockers
b) Adenyl cyclase blockers
c) Gai blockers
d) Calcium channel
calcium channel blockers
Q2) EDV: End diastolic volume = volume before contraction. What theoretical effect would hypercalcemia and increased EDV have on contractility and Cardiac output?
a) Increased contractility and cardiac output
b) Increased contractility but decreased cardiac output
c) Decreased contractility and cardiac output
d) Decreased contractility but increased cardiac output
increased contractility and cardio output
