Innervation to pelvis

Question 1

Describe the concept of the ‘pelvic pain line’

Answer 1

• Decided by relation to inferior peritoneum
• Structures above or in contact with inferior peritoneum - Sensation follow sympathetic innervation. Sympathetic innervation comes from the superior hypogastric plexus.
• Structures below the inferior peritoneum - Sensation follows parasympathetic (pelvic splanchnic nerves S2-4) supply.

Question 2

What nerve plexus may be injured during a radical hysterectomy during dissection of the parametrial tissues?
What are the short-term complications associated with this nerve plexus injury?

Answer 2

• The inferior hypogastric plexus may be injured.

- Results in voiding dysfunction and urinary retention.

Question 3

What nerve supplies sensory and motor function to the anterior thigh?
What is this nerves’ origin?

How can it be damaged?

Answer 3

• Femoral nerve
• Origin: lumbar plexus (L2-4)
• Injury occurs from retractor placement or by hyper flexion or external rotation of hip during lithotomy position
• Injury may lead to anaesthesia in the anterior and medial thigh and reduced flexion at hip and extension of knee, with absent patellar tap reflex

Question 4

What are the six branches of the lumbar plexus

Answer 4

Iliohypogastric (L1)
Ilioinguinal (L1)
Genitofemoral (L1,2)
Lateral cutaneous nerve of the thigh (L2, 3)
Obturator (L2-4)
Femoral (L2-4)

2 from 1, 2 from 2, 2 from 3

L1-4
Psoas major

Question 5

What are the 5 major peripheral nerves of the sacral plexus?

Answer 5

Superior gluteal (L4, L5, S1)
Inferior gluteal (L5, S1, S2)
Sciatic (L4-S3)
Posterior femoral cutaneous nerve (S1-3)
Pudendal nerve (S2-4)

Forms from the anterior rami of S1-4, with contribution from L4 and L5
Located on the surface of the posterior pelvic waLl, anterior to the piriformis

Question 6

What is the innervation of the pelvic viscera?

Answer 6

From the 2 inferior hypogastric plexuses; a broad expansion of nerves and ganglia lateral to the pelvic viscera. They receive neurones form the sympathetic and parasympathetic autonomic nervous systems:

Sympathetic:

• hypogastric nerves - a downward extension from the superior hypogastric plexus, laying anterior to the aorta around the level of its bifurcation
• sacral splanchnic nerves (a continuation of the sympathetic trunk)

Parasympathetic nerves:
- Pelvic splanchnic nerves from S2-S4

Sensory
- sensory efferents follows sympathetic fibres and correspond to levels T10 - L1

Question 7

What are the 3 divisions of the hypogastric plexus?

Answer 7

• vesical plexus
• uterovaginal plexus (Frankenhauser ganglion)
• middle rectal plexus

Question 8

What is the innervation of the ovary and fallopian tube?

Answer 8

Neural plexus companies ovarian vessels in IP ligament

Sympathetic from T10
Parasympathetic from branches of vagus nerve