QuestionSBA
QuestionChoice
The inhibition of β3-adrenoreceptors causes contraction of the detrusor muscle. These would not help alleviate urinary symptoms.
10024423
d
β3 adrenergic receptor antagonist
QuestionChoice
Activation of M3 receptors causes smooth muscle contraction in the bladder through the Gq receptor pathway. This would not alleviate urinary symptoms.
10024422
c
M3 muscarinic receptor agonist
QuestionChoice
The stimulation of β3-adrenoreceptors causes relaxation of the detrusor muscle. An example of a β3 receptor agonist is mirabegron which is used to treat overactive bladder syndrome.
10024424
e
β3 adrenergic receptor agonist
QuestionChoice
Tamsulosin is an alpha-1 adrenoceptor blocker. Blocking α1 receptors in the bladder causes detrusor muscle relaxation which improves urinary storage symptoms. This is used in conditions such as benign prostatic hyperplasia, which is what this gentleman is likely presenting with.
10024420
a
α1 receptor antagonist
QuestionChoice
This induces contraction of the internal urethral sphincter which prevents the flow of urine.
10024421
b
α1 receptor agonist
Concept
Chapter
2693
4538
Micturition reflex
Topic
168
Renal Physiology
17282
A 69-year-old male presents to his general practitioner due to difficulty in emptying his bladder and waking in the middle of the night to urinate. The GP prescribes him tamsulosin.

What is the mechanism of action of tamsulosin?
a