MRCS Part B Revision · Anatomy
Inguinal Region — MRCS Part B Anatomy
By Dr Richard Miller, MBChB FRCS · Reviewed
Inguinal Region is a surgical anatomy station. Three of the seventeen examined stations in the MRCS Part B OSCE are surgical anatomy. The anatomy stations put a prosected specimen, a model or an image in front of you and ask you to identify structures and say what they do, what they relate to and what happens when they are injured.
What you need to know for the Inguinal Region station
The Inguinal Region
The Inguinal Canal
The inguinal canal is a passage in the anterior abdominal wall which in men conveys the spermatic cord and in women the Round ligament of uterus. The inguinal canal is larger and more prominent in men. There is one inguinal canal on each side of the midline.
During development gonads (ovaries or testes) descend from their starting point on the posterior abdominal wall (para-aortically) from labioscrotal swelling near the kidneys down the abdomen and through the inguinal canal to reach the scrotum. The testis then descends through the abdominal wall into the scrotum, behind the processus vaginalis (which later obliterates). Thus lymphatic spread from a testicular tumour is to the para-aortic nodes first, and not the inguinal nodes.
Inguinal Canal Boundaries
Boundaries of inguinal canal (MALT):
Roof: internal oblique and transversus abdominis Muscle fibres
Anteriorly: external oblique Aponeurosis and internal oblique
Floor: Inguinal Ligament
Posteriorly: Transversalis fascia
Inguinal Canal Contents
The structures which pass through the canal differ between males and females:
Males : the spermatic cord and its coverings and the ilioinguinal nerve.
Females : the round ligament of the uterus and the ilioinguinal nerve.
Spermatic Cord Contents
The classic description of the contents of spermatic cord in the male are:
- 3 arteries: artery to vas deferens (or ductus deferens), testicular artery, cremasteric artery;
- 3 fascial layers: external spermatic, cremasteric, and internal spermatic fascia;
- 3 other structures: pampiniform plexus, vas deferens (ductus deferens), testicular lymphatics;
- 3 nerves: genital branch of the genitofemoral nerve (L1/2), sympathetic and visceral afferent fibres, ilioinguinal nerve (N.B. outside spermatic cord but travels next to it)
Images from this station
What are you asked at the Inguinal Region station?
The station runs to 20 questions over nine minutes. A prompt the station repeats — against each marker on a specimen, for instance — is listed once here; the model answers are in the question bank.
- Identify structures 1-5
- Identify structures 6-9
- Name the origin and insertion of the rectus abdominis muscle
- Name the origin and insertion of the external and internal oblique muscles
- What is the nerve supply of the abdominal muscles?
- From where does a spigellian hernia emerge?
- What is the inguinal canal
- What are the boundaries of the inguinal canal?
- Define the superficial and deep inguinal rings
- Name the contents of the inguinal canal
- What are the anatomical differences between a direct and an indirect inguinal hernia?
- What is the difference between the midinguinal point and mid-point of the inguinal ligament?
And 7 more at this station.
How is the anatomy station marked in MRCS Part B?
An anatomy station is marked out of 20, and all 20 marks go to clinical knowledge and its application. No communication, technical-skill or professionalism marks are available in an anatomy bay, which is unusual: in most other stations more than half the marks sit outside your factual knowledge.
FAQ
What does the Inguinal Region station ask?
It opens with "Identify structures 1-5" and runs to 20 questions over nine minutes. An anatomy station is marked out of 20, and all 20 marks go to clinical knowledge and its application. No communication, technical-skill or professionalism marks are available in an anatomy bay, which is unusual: in most other stations more than half the marks sit outside your factual knowledge.
How many anatomy stations are there in MRCS Part B?
Three of the seventeen examined stations are surgical anatomy, and two more are surgical pathology. Together they make up the five Anatomy and surgical pathology stations of the Applied Knowledge component.
How are the anatomy stations marked?
Each station is marked out of 20 and all 20 marks are awarded for clinical knowledge and its application. You also receive a separate global rating of pass, borderline or fail for the station.
Are the specimens real?
Yes. Anatomy bays use prosected cadaveric specimens, models and images. Candidates report being shown photographs of specimens as well as the specimens themselves, so practise on real dissection photography rather than diagrams alone.
What happens if I get an early question wrong?
The intercollegiate guidance says that if a wrong answer would affect your performance on later questions at the same station, the examiner gives you the correct answer before moving on. One mistake does not have to cost you the whole bay.
How many stations are in the MRCS Part B OSCE?
Seventeen examined stations of nine minutes each, with a minute to read the task before each one. Two preparation stations and at least one rest station bring the circuit to about twenty, and the exam takes about three and a half hours.
What is the pass mark for MRCS Part B?
There is no published pass mark. The cut score is set separately for Applied Knowledge and Applied Skills, for each circuit, by borderline regression. Published pass rates across the 2024/25 diets ranged from 51% to 66%.
Can I fail a station and still pass?
Yes. There is no rule about how many stations you may fail: the cut score applies to your total mark in each component, so a weak station costs the marks you lost on it and strong stations elsewhere can make them back. Applied Knowledge and Applied Skills are passed separately and must both be passed at the same sitting, so a strong anatomy performance cannot rescue a weak communication one.
Dr Richard Miller, MBChB FRCS
Station summaries are reviewed against the current intercollegiate MRCS syllabus and the published marking blueprint. Guidance changes between diets: check the royal colleges' own pages before relying on a date, a fee or a threshold.
Practise this station
The question bank carries the model answer to every question above, with the rest of the anatomy stations.
More anatomy stations