Physiology of the Urinary Tract

Question 1

The kidneys lie between T__ - __

Answer 1

T11-L3

Question 2

How are the kidneys supplied?

Answer 2

Renal artery from aorta at L1 level

Question 3

Every day, each kidney produces - litres of urine per day

Answer 3

1-1.5 litres

Question 4

How long are the ureters?

Answer 4

25-30cm

Question 5

What muscle do the ureters lie over?

Answer 5

Psoas

(Cross the iliac vessels at the pelvic brim and insert into trigone of bladder)

Question 6

Urine is produced by the kidney and enters the renal pelvis and is transported via ______ down the ureter into the bladder

Answer 6

Peristalsis

Question 7

How is parasympathetic involuntary control transmitted to the bladder and sphincter?

Answer 7

Pelvic nerve
S2-S4
Acetylcholine

Question 8

How is sympathetic involuntary control transmitted to the bladder and sphincter?

Answer 8

Hypogastric plexus
T11-L2
Noradrenaline neurotransmitter

Question 9

What somatic nerve is for voluntary control of the bladder and sphincter?

Answer 9

Pudendal nerve
S2-S4 (Onuf’s nucleus) to external sphincter
Acetylcholine neurotransmitter

Question 10

What is the sensory nerve for the bladder and sphincter?

Answer 10

Afferent pelvic nerve
Signals from detrusor muscle

Question 11

What is the normal adult bladder capacity?

Answer 11

400-500 ml

Question 12

As the volume in the bladder increases, the pressure remains low due to “r_____ r____” and detrusor muscle compliance

Answer 12

receptive relaxation

Question 13

At lower volumes in filling phase, the ____ ____ nerve sends slow firing signals to the pons via the spinal cord

Answer 13

afferent pelvic

Question 14

The firing of which nerve maintains relaxation of the detrusor muscle?

Answer 14

Sympathetic nerve (hypogastric plexus)

Question 15

Which nerve maintains urethral contraction when stimulated?

Answer 15

Somatic (pudendal) nerve

Question 16

Micturition reflex is an autonomic ____ reflex

Answer 16

spinal

Question 17

Higher volumes in the bladder stimulate the ____ ____ nerve to send fast signals to the micturition centre in the sacral spinal cord

Answer 17

afferent pelvic nerve

Question 18

When the pelvic parasympathetic nerve is stimulated the detrusor muscle ____

Answer 18

contracts

Question 19

When the pelvic parasympathetic nerve is stimulated, which nerve is inhibited causing the external sphincter to relax?

Answer 19

Pudendal nerve

Question 20

When guarding (eg not socially acceptable for micturition), afferent signals are received by the ___ / ___ and transmitted to the higher cortical centres

Answer 20

PMC / PAG
Pontine Micturition Centre /
Periaqueductal grey matter

Question 21

Stimulation of which nerve results in detrusor relaxation (guarding)?

Answer 21

Sympathetic (hypogastric) nerve

Question 22

Stimulation in which nerve results in contraction of the external urethral sphincter?

Answer 22

Pudendal nerve