Shortest part of male urethra is?

Appeared in: NIA - 29 January 2023

Explanation

The male urethra is divided into three segments: prostatic, membranous, and spongy.
The membranous urethra is the shortest of these segments, measuring approximately 1 to 2 cm in length.
It is also the narrowest and least distensible part, making it susceptible to injury during procedures like catheterization.
It passes through the deep perineal pouch and is surrounded by the external urethral sphincter.

Option A: The prostatic urethra is approximately 3-4 cm long, which is longer than the membranous urethra.
Option B: The spongy (or penile) urethra is the longest part of the male urethra, measuring about 15 cm.
Option D: The glans is the head of the penis, not a segment of the urethra. The urethra passes through the glans, but the glans itself is not a part of the urethra.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy of the male urethra as background academic context rather than a clinical decision trigger.
The membranous urethra's short length and narrowness make it a critical area during male urinary catheterization. It is the most common site of iatrogenic injury.
Nurses must use a gentle technique, adequate lubrication, and proper patient positioning (aligning the penis) to navigate the catheter through this segment without causing trauma or creating a false passage.
What if? If a patient has a history of urethral stricture (narrowing), especially in the membranous area, catheterization becomes even more high-risk. A smaller catheter size (e.g., 12-14 Fr) might be required, or a urologist may need to perform the procedure using specialized equipment like a guidewire.

How to Approach the Question

This is a factual recall question based on anatomical knowledge.
First, identify the key terms in the question: 'shortest part' and 'male urethra'.
Recall or visualize the three segments of the male urethra: prostatic, membranous, and spongy.
Compare the relative lengths of these three parts.
Eliminate options that are incorrect. 'Glans' is a part of the penis, not a distinct segment of the urethra.
Select the option that corresponds to the shortest segment, which is the membranous urethra.

Concept Tested & Keywords

Concept Tested: Anatomy of the male urethra
Stem keywords: shortest part, male urethra
Lead-in keywords: is
Clinical cues: Age/sex group narrows the expected diagnosis, intervention, or normal reference range.
Negative lead-in flag: false

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E6 Nursing Fundamentals Taylor p. 585-587

E6 Nursing Fundamentals Potter Perry 12e Part 5 p. 234-236

Practise the full NIA - 29 January 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.