Anatomy- renal continence and renal system pain

Question 1

What are the five nerve modalities?

Answer 1

Sensory- somatic and visceral afferent

Motor- sympathetic and parasympathetic, somatic

Question 2

Summarise the sympathetic supply to the body.

Answer 2

Thoracolumbar outflow- sympathetic neurones exit the spinal cord T1-T2
Enter the sympathetic chain ganglia
Fibres innnervating the soma- synapse in sympathetic chain ganglia, and enter spinal nerves
Fibres innervating visceral structures leave the sympathetic chain and enter SPLANCHNIC/SYMPATHETIC nerves, following the arteries to the structures they innervate

Question 3

How do sympathetic fibres reach the kidney, ureter and bladder?

Answer 3

Exit the spinal cord between T10-L2, within abdomenopelvic splanchnic nerves, synapse in the abdominal sympathetic ganglia and latch onto arteries going to the structures they innervate

Question 4

How are parasympathetic fibres carried to the

a) kidney and ureter
b) bladder

Answer 4

a) vagus nerve (CN X)

b) pelvic splanchnic nerves (S2-S4)

Question 5

Which nerve/nerve modality are responsible for:

a) bladder contraction
b) internal urethral sphincter relaxation/contraction
c) external urethral sphincter contraction
d) levator ani contraction

Answer 5

a) parasympathetic fibres from pelvic splanchic nerves
b) parasympathetic fibres from pelvic splanchic nerves
sympathetic fibres (during ejaculation)
c) somatic motor within the pudendal nerve (S2-S4)
d) somatic motor within the nerve to levator ani (S3-S4)

Question 6

Why are the nerves leaving S2-S4 vital to the voluntary control of micturition?

Answer 6

Carry:

• visceral afferents (detect when bladder is full)
• pelvic splanchic nerves- responsible for bladder contraction and internal sphincter relaxation
• pudendal nerve- controls external urethral sphincter contraction
• nerve to levator ani- controls

Question 7

Where is pain from the following structures usually felt:

a) kidneys
b) ureter
c) bladder
d) urethra
e) testes

Answer 7

a) dull, achey pain in the posterior flank region
b) “loin to groin”
c) suprapubic
d) localised within the perineum
e) often felt in scrotum but also anterior lower abdomen (due to embryogical origin)

Question 8

What is the “nerve of the perineum”?

Answer 8

The pudendal nerve

Question 9

Give the nerve root and function of:

a) femoral nerve
b) obturator nerve
c) lateral femoral cutaneous nerve

Answer 9

a) L2-L4- anterior thigh muscles and anterior thigh skin
b) L2-L4- adductors of hip, medial thigh skin
c) L2-L3- skin over lateral surface of thigh

Question 10

Which nerves root is the sciatic nerve formed from, and what are it’s branches?

Answer 10

L4-S3, tibial and common fibular