MRCS Part B Revision · Anatomy
Oropharynx — MRCS Part B Anatomy
By Dr Richard Miller, MBChB FRCS · Reviewed
Oropharynx 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 Oropharynx station
A sagittal section through the head and neck, with the pharynx in the middle of it. The numbered structures run from the palate to the larynx and out to the skull base, so the summary follows the same route.
The three parts of the pharynx
The nasopharynx lies behind the nasal cavity above the soft palate, with the opening of the auditory tube on its lateral wall, the tubal elevation behind it, and the adenoid in its roof. The oropharynx lies behind the mouth, from the soft palate to the tip of the epiglottis, opening forward through the oropharyngeal isthmus between the palatoglossal folds. The laryngopharynx runs from the epiglottis to the lower border of the cricoid at C6, where it becomes the oesophagus, with the piriform fossae either side of the laryngeal inlet.
The oropharynx
Its anterior wall is the back of the tongue and the valleculae, the two hollows between the tongue and the epiglottis where a fish bone lodges. Its lateral wall carries the palatine tonsil in the tonsillar fossa between the palatoglossal fold in front and the palatopharyngeal fold behind. Its roof is the under-surface of the soft palate and the uvula. The walls are lined by non-keratinised stratified squamous epithelium, and the tonsils, adenoid and lingual tonsil together form Waldeyer's ring.
The tonsil
Lymphoid tissue on the superior constrictor, supplied by the tonsillar branch of the facial artery, with the paratonsillar vein on its lateral surface, which is the vessel that bleeds after tonsillectomy. The glossopharyngeal nerve runs close behind the bed, so tonsillar pain is referred to the ear. The internal carotid artery lies about 2.5 cm posterolateral to it.
Swallowing
The soft palate rises to close the nasopharynx (levator veli palatini), the larynx rises and the epiglottis folds back over the inlet, the vocal folds close, and the constrictors sweep the bolus down. The whole sequence is under the vagus, with the pharyngeal plexus supplying every pharyngeal and palatal muscle except stylopharyngeus (glossopharyngeal) and tensor veli palatini (mandibular nerve).
Bones and vessels on the section
The hyoid bone at C3 with the hyoid muscles above and below it; the hard palate, the nasal septum and the sphenoid sinus in the midline; the atlas and axis behind the pharynx with the dens; the cricoid ring at C6 and the thyroid cartilage above it. The vessels seen laterally are the common carotid dividing at C4, the internal carotid running up without branches behind the pharynx, and the external carotid giving the lingual and facial arteries towards the tongue and tonsil.
Images from this station
What are you asked at the Oropharynx station?
The station runs to 21 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 and 2
- Identify structure 3
- Identify structures 4 and 5
- Identify structures 6 and 7
- Identify areas 8 and 9
- Identify structure 10
- Identify the isthmus located at 11
- Identify folds 12 and 13
- Identify structure 14
- Identify structure 15
- Identify structures 16 and 17
- What is structure 18?
And 8 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 Oropharynx station ask?
It opens with "Identify structures 1 and 2" and runs to 21 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