Male pelvis

Question 1

Name the parts of the male urethra and their key features.

Answer 1

Intramural (surrounded by internal urethral sphincter)

Prostatic (widest, most dilatable part)

Intermediate (= membranous) surrounded by external urethral sphincter)

Spongy (penile part, 15cm long)

Question 2

What is the innervation of the urethra?

Answer 2

Prostatic nerve plexus (to the first 3 parts)

Dorsal nerve of the penis - from the pudendal nerve (to the spongy penile part)

Question 3

Which part of the male urethra is the narrowest?

Answer 3

Intermediate (membranous) part, and the external orifice.

Question 4

Describe the innervation of the bladder.

Answer 4

Sympathetic innervation to the internal urethral sphincter, causing contraction during ejaculation and in times of anxiety. Parasympathetic innervation to the bladder’s detusor muscles, causing contraction during micturition.

Question 5

Describe the course of the ureters, and identify the narrow parts.

Answer 5

- 25-30cm long

- Run from renal hila inferiorly

- Lie just medial to tips of lumbar transverse processes

- Pass over pelvic brim at bifurcation of common iliacs

- Inserts at posterior wall of bladder

- Narrow points are PUJ, pelvic brim, VUJ

(3/5 and 2 narrow points to pass)

Question 6

What is the arterial blood supply of the ureter?

Answer 6

Renal and gonadal arteries