Inferior hypogastric plexuses and sacral sympathetic trunks (daves notes only)

Question 1

Describe the inferior hypogastric plexuses and their location

Answer 1

There is a right and left hypogastric plexus which together form the single pelvic plexus. This is an autonomic plexus on the sidewall of the pelvis (lateral to the rectum).

Question 2

What are the inputs to the inferior hypogastric plexuses, and where do these come from?

Answer 2

• Sympathetic and parasympathetic input.
• Sympathetic from lumbar ganglia (pre and post ganglionic), and sacral ganglia (pre and post ganglionic).
• Parasympathetic is from S2,3,4

Question 3

Describe the myelination and relay of the inferior hypogastric plexus

Answer 3

Half of the fibres are myelinated preganglionic relaying in the iliohypogastric plexus. The remaining fibres (including all of the parasympathetic) pass through without relay

Question 4

What do sympathetic vasoconstrictor fibres do? What else do they supply (list).

Answer 4

Sympathetic vasoconstrictor fibres accompany all vessels and are also motor to:
Bladder sphincter
Anal canal sphincter
Ductus deferens
Seminal vesicles
Prostatic muscle
Uterine muscle

Question 5

What is the role/destination of pelvic parasympathetic nerves?

Answer 5

Motor to detrusor

Secretomotor to the gut from the splenic flexure down.

Question 6

What sensory supply arises from what pathways in the inferior hypogastric plexus?

Answer 6

Sensory supply to abdominal viscera and gonads via sympathetic pathways

Question 7

What also receives pelvic parasympathetic supply? What is the developmental significance of this?

Answer 7

Cloacal derivatives: Bladder, rectal ampulla and anal canal also receive pelvic parasympathetics as does lower cervix and upper vagina