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===Innervation===
 
===Innervation===
 
The bladder receives sympathetic and parasympathetic nerve supply.
 
The bladder receives sympathetic and parasympathetic nerve supply.
*Parasympathetic supply: This comes from S1-S3, synapses within the '''pelvic plexus''', continues as the '''pudendal nerve''' and is excitatory to the destrusor muscle. Parasympathetic dominance allows emptying of the bladder.
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*'''Parasympathetic supply''': This comes from S1-S3, synapses within the '''pelvic plexus''', continues as the '''pudendal nerve''' and is excitatory to the destrusor muscle via release of Acetylcholine which binds muscarinic acetylcholine receptors. Parasympathetic dominance allows emptying of the bladder.
*Sympathetic Supply: This comes from L1-L4, synapses within the '''caudal mesenteric ganglion''' before entering the '''pelvic plexus. It then continues as the '''hypogastric nerves''' which terminate on beta 2 receptors within the detrusor muscle. It has inhibitory action on muscular contraction, therefore enabling bladder filling.
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*'''Sympathetic Supply''': This comes from L1-L4, synapses within the '''caudal mesenteric ganglion''' before entering the '''pelvic plexus'''. Postganglionic fibres continue as the '''hypogastric nerves''', which terminate on beta 2 receptors within the detrusor muscle. It has inhibitory action on muscular contraction, therefore enabling bladder filling.
    
==Urethra==
 
==Urethra==
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