Adrenoreceptors

Question 1

Noradrenaline acts on which receptors?

Answer 1

Alpha 1/2 and beta 1/2

Question 2

Adrenaline acts on which receptors?

Answer 2

Alpha 1/2 and beta 1/2

Question 3

Dopamine acts on which receptors?

Answer 3

Dopmaine specific receptor and also alpha and beta adrenoreceptors

Question 4

What do the alpha adrenoreceptors do?

Answer 4

A1 (remember CONSTRICT):

• Veno and vasoconstriction
• Smooth muscle sphincter contraction
• Squeeze out sweat glands
• Squeeze iris muscles - cause dilatation
• Randomly causes glycogenolysis

A2 (CONSTRICT):

• Vasocontriction but no effect on cerebral and coronary vessels
• Decrease insulin secretion

Question 5

What do beta adrenoreceptors do?

Answer 5

B1 (REMEMBER ONE HEART, it does heart stuff):

• Increase heart rate, increase contractility
• Increase SBP but no change on DBP
• Increase excitability
• Increase conduction velocity
• Increase Cardiac O2 consumption
• Increase lipolysis to free energy for body

B2 (REMEMBER TWO LUNGS RELAX):

• Brochodilation
• Gut and bladder dilation
• Muscle and liver vasodilation
• Glycogenolysis