MRCS Part B Revision · Anatomy
Mediastinum 1 — MRCS Part B Anatomy
By Dr Richard Miller, MBChB FRCS · Reviewed
Mediastinum 1 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 Mediastinum 1 station
The Medistinum (1)
The Mediastinum
The mediastinum lies between the right and left pleurae in and near the median sagittal plane of the chest. It extends from the sternum in front to the vertebral column behind, and contains all the thoracic organs except the lungs. It may be divided for purposes of description into two parts: an upper or superior part and a lower or inferior part.
The superior mediastinum extends from the upper level of the pericardium with its upper limit at the superior thoracic aperture and its lower limit at the thoracic plane which runs from the sternal angle (the joint between the manubrium and the body of the sternum) to the intervertebral disc of T4-T5. The (transverse) thoracic plane divides the mediastinum into these upper and lower parts. The inferior mediastinum extends below the upper level of the pericardium onto the diaphragm. This lower part is subdivided into three regions all relative to the pericardium. The anterior mediastinum is in front of the pericardium. The middle mediastinum contains the pericardium and its contents. The posterior mediastinum is behind the pericardium.
It is surrounded by the chest wall in front, the lungs to the sides and the spine at the back. It is continuous with the loose connective tissue of the neck.
Images from this station
What are you asked at the Mediastinum 1 station?
The station runs to 15 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.
- How is the mediastinum anatomically divided?
- What are the boundaries of the superior mediastinum?
- What are the contents of the superior mediastinum?
- Which area of the mediastinum does this specimen demonstrate
- Identify structures 1-2
- Identify structures 3-4
- Identify vessels 5-8
- Identify structure 9
- Identify vessels 10-12
- Identify vessels 13-16
- What is structure 17
- Identify nerves 18-19
And 2 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 Mediastinum 1 station ask?
It opens with "How is the mediastinum anatomically divided?" and runs to 15 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