Adrenergic effects Flashcards
SYmpathetic responses (17 cards)
What does the α1 receptor activate? [1 mark]
It activates phospholipase C (PLC)
What does the α2 receptor inhibits? [1 mark]
It inhibits adenylyl cyclase
What do β receptors stimulate? [1 mark]
They activate adneylyl cyclase
Which adrenaline form is more potent in α-adrenoceptors? [1 mark]
Noradrenaline
Which adrenaline form is more potent in β-adrenoceptor? [1 mark]
Adrenaline
What do α1-adrenoceptors do? [1 mark]
Constrict blood vessels
What do α2-adrenoceptors do? [1 mark]
Inhibits transmitter release
What do β1-adrenoceptors do? [3 marks]
- Increase heart rate
- Increase force of contraction
- Increase blood pressure
What do β2-adrenoceptors do? [2 marks]
- Vasodilation
- Bronchodilation
What does protein kinase A do to voltage gated calcium ion channels? [1 marks]
Keeps them more responsive to voltage
What do beta and gamma subunits of Gαi do at nerve terminals? [3 marks]
- They turn on a potassium channel
- This hyperpolarises the nerve terminal
- This suppresses depolarisation
What is the funny channel? [2 marks]
- sodium/potassium ion channel opened by hyperpolarisation
- More responsive with cAMP bound
What do β2-adrenoceptors do? [2 marks]
- Lipolysis
- Relax the detrusor muscle (for urine storage)
What is renin? [2 marks]
- An aspartic protease in the juxta glomerular apparatus (JGA)
- Converts angiotensinogen to angiotensin I
Which G protein mediates the cardiac effects of noradrenaline? [1 mark]
Gαs
What does propanolol block and what are its effects? [3 marks]
- β-adrenoceptors
- Brachycardia
- VAsoconstriction
What does prazosin do? [3 marks]
- dilates resistance arterioles
- lowers blood pressure by reducing α1-adrenoceptor- mediated vasoconstriction
- may cause postural hypotension
