Storage and emptying of the bladder

1. How do alpha-adrenergic receptors respond to NE? Beta receptors?
2. What is the innervation of the internal urethral sphincter?
3. What is the innervation of the external urethral sphincter?
4. What is the job of alpha-1 adrenergic receptors in bladder storage? What is the job of B2 adrenergic receptors in bladder storage?
5. What is the job of M2 muscarinic cholinergic receptors in bladder emptying? What is the role of B2 adrenergic receptors in bladder emptying?

Answers:
1. Alpha responds with contraction, beta responds with relaxation.
2. T11-T12 sympathetic nerve.
3. S2-S4 pudendal nerve, under voluntary control.
4. Alpha-1 receptors close the internal spincter and detrusor outlet, promoting bladder storage. B2 receptors are located in the body of the bladder and result in relaxation of the body of the bladder to allow for storage.
5. M2 receptors allow for contraction of the bladder and emptying. B2 receptors in the bladder neck relax, allowing for voiding.