Micturition

Question 1

Explain the urinary consequences of cauda eqiuna. (6)

Answer 1

Painless retention of urine - stretch receptors damaged.
Urinary incontinance - EUS relaxes due to pudendal nerve loss.
Retention - sympathetics maintain bladder in relaxed state.

Question 2

Explain the urinary consequences of a thoracic spinal cord lesion. (4)

Answer 2

Parasympathetic stimulation would decrease because all stimulating higher thinking impulses were lost, so the detrusor muscle would not be told to contract by parasympathetics, causing urinary retention and hydronephrosis from the back pressure.

Question 3

Explain the differences in internal urethral sphincter between men and women. (2)

Answer 3

More prominent in men to prevent retrograde ejaculation.

Question 4

Describe the volume indicators of bladder fullness. (2)

Answer 4

150ml - awareness

500ml - overwhelming urge to urinate.