Urinary Continence and Renal Pain

Question 1

What nerve fibres give sensory innervation?

Answer 1

Somatic sensory = sensations from body wall

Visceral afferent = sensations from organs

Question 2

What nerve fibres give motor innervation?

Answer 2

Somatic motor = motor responses to body wall and stimulate skeletal muscle to contract
Parasympathetic/sympathetic = stimulate smooth and cardiac muscle and glands

Question 3

What nerves modalities control ureteric peristalsis and bladder contraction?

Answer 3

Sympathetic and parasympathetic

Question 4

What nerve modalities are responsible for urethral sphincter control?

Answer 4

Sympathetic and parasympathetic = internal sphincter

Somatic motor = external sphincter, levator ani

Question 5

What nerve modality is responsible for the perception of pain from the kidneys, ureters and bladder respectively?

Answer 5

Visceral afferent nerve fibres

Question 6

What nerve modality is responsible for pain from the urethra?

Answer 6

Visceral afferent in pelvis

Somatic sensory in perineum

Question 7

What nerve modality is responsible for pain from the testes?

Answer 7

Visceral afferents with some somatic presentation also

Question 8

What modalities are involved in the voluntary control of urinary elimination?

Answer 8

Sympathetic, parasympathetic, somatic motor, visceral afferent

Question 9

Where do the lumbar and sacral plexuses supply?

Answer 9

Perineum and lower limbs = supply both somatic motor and sensory

Question 10

How many pairs of spinal nerves are there?

Answer 10

31 pairs in total = 12 pair of cranial nerves

Question 11

What is the only way any type of nerve fibre can communicate with the CNS?

Answer 11

By being carried within the cranial or spinal nerves

Question 12

Where do sympathetic fibres leave the CNS?

Answer 12

Within spinal nerves between T1-L2 (thoracolumbar outflow) = join somatic motor and sensory fibres

Question 13

How do sympathetic fibres reach the smooth muscle and glands of the body wall?

Answer 13

Within spinal nerves

Question 14

How do sympathetic fibres reach the smooth muscle and glands in the body?

Answer 14

Within the splanchnic nerves = cardiopulmonary or abdominopelvic

Question 15

How do sympathetic fibres reach the head?

Answer 15

Follow the arteries which supply the same structure

Question 16

What level do sympathetic fibres leave the cord at to supply the urinary system?

Answer 16

Between T10-L2 levels = enter sympathetic chain bilaterally but don’t synapse

Question 17

What do sympathetic fibres leave the sympathetic chain with when travelling to supply the urinary system?

Answer 17

Abdominopelvic splanchnic nerves

Question 18

Where do sympathetic fibres synapse when travelling to the urinary system?

Answer 18

Synapse at the abdominal sympathetic ganglia = located around the abdominal aorta

Question 19

Where do post-synaptic sympathetic fibres pass to once they leave the abdominal sympathetic ganglia?

Answer 19

Pass onto the surface of the arteries which head towards the organs

Question 20

What is a peri-arterial plexus?

Answer 20

Collection of nerve fibres found on the outside of arteries = also contain parasympathetic and visceral afferent fibres

Question 21

How do parasympathetic fibres leave the CNS?

Answer 21

Within four cranial nerves = CN III, VII, IX and X

Within the sacral spinal nerves

Question 22

Do parasympathetic fibres supply the smooth muscle and glands of the body wall?

Answer 22

No = supply smooth muscle and glands of head and body

Question 23

How do parasympathetic fibres reach the hindgut and pelvic organs?

Answer 23

Via pelvic splanchnic nerves = also carried briefly within sacral spinal nerves

Question 24

What cranial nerve carries parasympathetic fibres to the kidneys and ureters?

Answer 24

Vagus nerve (CN X)

Question 25

What nerves innervate the bladder?

Answer 25

Pelvic splanchnic nerves = S2-4

Question 26

Where do somatic motor fibres supply?

Answer 26

Only structures of the body wall

Question 27

What parts of the renal system receive somatic motor fibres?

Answer 27

Only parts within the perineum = urethra distal to the pelvic floor, external urethral sphincter, levator ani

Question 28

What are some nerves that carry somatic motor fibres to the urinary system?

Answer 28

S2-4, pudendal nerve

Question 29

Where is pain from the kidney felt?

Answer 29

Dull, achy pain felt in loin = posterior aspect of flank on affected side, usually felt in dermatomes

Question 30

Where is pain from the bladder felt|?

Answer 30

Midline in the suprapubic region = dull, achy pain

Question 31

Where is pain from the perineal part of the urethra felt?

Answer 31

Quite localised in the perineum

Question 32

Where is pain caused by a calculus obstructing the ureter felt?

Answer 32

Radiates from loin to groin on affected side

Question 33

Where is pain from the distal urethra felt?

Answer 33

Localised within perineum = sharp pain

Question 34

Where is pain from the testes felt?

Answer 34

Often felt in scrotum but can radiate to groin and anterior lower abdomen

Question 35

Where do visceral afferent fibres from the kidney travel?

Answer 35

Run alongside sympathetic fibres back to spinal cord = enter spinal cord between T11 and L1

Question 36

What are some differentials for loin pain?

Answer 36

Skin origin (e.g shingles), muscular pain, vertebrae pain, spinal nerve root compression, lower lobe pneumonia

Question 37

Where do visceral afferent fibres from the ureters enter the spinal cord?

Answer 37

Between T11 and L2 level = pain may be felt anywhere along their path

Question 38

What are some differentials of groin pain?

Answer 38

Hernias (inguinal, femoral), lymphadenopathy, testicular pathology

Question 39

What part of the bladder do visceral afferent fibres carry pain from?

Answer 39

The part that touches the peritoneum = return to spinal cord at T11-L2 level

Question 40

Where do visceral afferent fibres from parts of the bladder not touching the peritoneum enter the spinal cord?

Answer 40

Run alongside parasympathetic fibres back to spinal cord between S2-4

Question 41

What are some differentials of supra-pubic pain?

Answer 41

Hindgut organ pain, other single midline pelvic organs whose superior aspect touches the peritoneum

Question 42

What part of the urethra do visceral afferent fibres innervate?

Answer 42

Proximal urethra (above levator ani and in pelvis) = run alongside parasympathetic fibres back to spinal cord at S2-4 level

Question 43

Where do somatic sensory fibres that supply the areas of the urethra not innervated by visceral afferent fibres enter the spinal cord?

Answer 43

Carried within pudendal nerve to S2-4 level = pain localised in perineum

Question 44

What are some differentials of perineal pain?

Answer 44

Vaginal tear, anal canal fissure, perineal genital ulcers

Question 45

Why do visceral afferent fibres from the testes run alongside the sympathetic fibres?

Answer 45

Due to their embryological descent = enter spinal cord at T10-11

Question 46

Why can pain from the testes sometimes be felt in the L1 region?

Answer 46

Due to their close relationship with the scrotal wall = pain may be localised to scrotum or groin

Question 47

What are the differentials of scrotal pain?

Answer 47

Skin lesions, strangulated inguinal hernia

Question 48

What level of the spinal cord is essential in controlling urine flow?

Answer 48

S2-4

Question 49

What modalities are present at S2-4 level?

Answer 49

Visceral afferents entering Pelvic splanchnic nerves (parasympathetic) leaving Pudendal nerves formed at this level = carry somatic sensory and motor nerve fibres

Question 50

What happens when the bladder fills?

Answer 50

Sensed by stretch receptors at end of visceral afferent fibres = relayed to CNS at S2-4 levels

Question 51

What bladder reflex only occurs in males?

Answer 51

Reflex to empty bladder by stimulation of detrusor muscle and inhibition of internal sphincter muscle

Question 52

Why are adults and potty trained children able to over-ride reflexive bladder voiding?

Answer 52

Have action potentials within inhibitory nerve fibres from the cortex which pass inferiorly

Question 53

What are adults able to do in regards to the bladder that infants cannot?

Answer 53

Voluntarily contract external sphincter and levator ani muscles

Question 54

What happens when an adult decides to void their bladder?

Answer 54

``` Detrusor contracts (parasympathetic) Internal urethral sphincter (parasympathetic), external urethral sphincter and levator ani relax (somatic motor) ```

Question 55

Why do the anterolateral abdominal wall muscles contract during bladder voiding?

Answer 55

Increases intra-abdominal pressure and forces urine out of the external urethral orifice = under somatic motor control

Question 56

What forms nerve plexuses?

Answer 56

Anterior rami of spinal nerves

Question 57

What nerves does the sacral plexus give rise to?

Answer 57

Pudendal nerve = S2-4 | Sciatic nerve = L4-S3

Question 58

What are some nerves given off by the lumbar plexus?

Answer 58

Iliohypogastric and ilioinguinal nerves = L1 level Lateral cutaneous nerve of the thigh = L2-3 levels Femoral and obturator nerves = L2-4 levels Genitofemoral nerve = L1-2 levels

Question 59

What structure is the femoral nerve located under?

Answer 59

The inguinal ligament = supplies anterior compartment of thigh, becomes saphenous nerve

Question 60

What structure does the obturator nerve pass through to supply the medial compartment of the thigh?

Answer 60

Obturator foramen

Question 61

How does the sciatic nerve reach the posterior compartment of the thigh?

Answer 61

Goes via the gluteal region = splits into tibial nerve and common fibular nerve

Question 62

Where does the tibial nerve supply?

Answer 62

Posterior compartment of leg and intrinsic muscles of foot

Question 63

Where does the common fibular nerve supply?

Answer 63

Deep branch = anterior compartment of leg | Superficial branch = lateral compartment of leg

Question 64

What nerves form the sural nerve?

Answer 64

Tibial and common fibular nerves = supplies sensation to lateral aspect of foot

Question 65

What supplies the first web space of the foot?

Answer 65

Deep fibular nerve

Question 66

What supplies sensation to the plantar aspect of the foot?

Answer 66

Tibial nerve

Question 67

What controls ureteric peristalsis?

Answer 67

Automatic action initiated and propagated by ureteric cells which have their own auto-rhythmicity

Question 68

What controls bladder contraction?

Answer 68

Parasympathetic fibres from S2-4 via pelvic splanchnic nerves stimulate detrusor muscle to contract

Question 69

What causes the internal urethral sphincter to contract in males?

Answer 69

Stimulation by sympathetic fibres = occurs during ejaculation

Question 70

What causes the internal urethral sphincter to relax?

Answer 70

Stimulation by parasympathetic fibres = allows urine to flow through urethra

Question 71

What causes the external urethral sphincter to contract?

Answer 71

Somatic motor fibres within the pudendal nerve (S2-4)

Question 72

What causes the levator ani to contract?

Answer 72

Somatic motor fibres within the nerve to levator ani (S3-4)