Bladder Function (Neurological Pathologies)

Automatic bladder
- partial emptying when bladder volume approx. 250ml
- spinal cord lesion above S2, 3, 4

Automatous bladder
- weak uncoordinated bladder contractions without desire to micturate
- lower motor neuron cord lesion @ S2, 3, 4

Atonic bladder
- distended bladder with overflow
- sensory neuropathies (eg. Diabetes)

Parasympathetic Nervous System

Afferent branch of micturition reflex runs in spinal cord via parasympathetic nerves to pontine micturition centre (under voluntary control).

Efferent branch runs from pontine micturition centre to sacral micturition centre (S 2, 3, 4).
- preganglionic parasympathetic –> pelvic plexus –> bladder (causes contraction of detrusor muscles)
- also inhibits hypogastric and pudendal nerves, causing relaxation of outflow region and pelvic floor