MRCS Part B Revision · Anatomy
Parotid Gland — MRCS Part B Anatomy
By Dr Richard Miller, MBChB FRCS · Reviewed
Parotid Gland 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 Parotid Gland station
The parotid region dissected, with the structures that pass through the gland and the facial nerve branches on its surface.
The gland
A serous salivary gland wedged between the ramus of the mandible in front and the mastoid process and sternocleidomastoid behind, below the external acoustic meatus, with a deep part reaching in towards the styloid process. It is enclosed in a tough capsule from the investing fascia, which is why parotitis is so painful. Its duct leaves the anterior border, crosses masseter a finger's breadth below the zygomatic arch, turns in through buccinator and opens into the mouth opposite the upper second molar. Parasympathetic secretomotor fibres come from the glossopharyngeal nerve through the otic ganglion and reach the gland on the auriculotemporal nerve.
Structures within it
From superficial to deep: the facial nerve and its branches, the retromandibular vein, and the external carotid artery dividing into the superficial temporal and maxillary arteries. The great auricular nerve supplies the skin over it, and the auriculotemporal nerve runs up behind the temporomandibular joint with the superficial temporal vessels.
The facial nerve
It leaves the stylomastoid foramen, gives the posterior auricular nerve and branches to the posterior belly of digastric and stylohyoid, and enters the gland, where it divides into upper and lower divisions and then into five terminal branches that emerge from the anterior border: temporal, zygomatic, buccal, marginal mandibular and cervical. The temporal branch crosses the zygomatic arch to frontalis and orbicularis oculi; the zygomatic branches supply orbicularis oculi; the buccal branches supply buccinator and the upper lip; the marginal mandibular branch runs along the lower border of the mandible to the muscles of the lower lip; the cervical branch supplies platysma.
Muscles seen
Masseter from the zygomatic arch to the angle and ramus of the mandible; temporalis passing under the arch to the coronoid process; buccinator in the cheek; the posterior belly of digastric and stylohyoid emerging from behind; sternocleidomastoid below; and the muscles of facial expression — orbicularis oculi, zygomaticus major, orbicularis oris, depressor anguli oris and platysma.
Clinical points
A parotid lump is a pleomorphic adenoma until proved otherwise; facial weakness with it means malignancy. Parotidectomy dissects the gland off the nerve, which is found at the stylomastoid foramen using the tragal pointer, the posterior belly of digastric and the tympanomastoid suture as landmarks. Frey's syndrome, sweating on the cheek when eating, follows regrowth of parasympathetic fibres into the sweat glands of the skin.
Images from this station
What are you asked at the Parotid Gland station?
The station runs to 14 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 structure 1
- Identify muscles 2 and 3
- Identify structures 4-6
- Identify muscle 7
- Identify muscle 8
- Identify muscle 9
- Identify structures 10-12
- Identify arteries 13 and 14
- Identify veins 15 and 16
- What is structure 17?
- Identify branches 18 and 19
- Identify branch 20
And 1 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 Parotid Gland station ask?
It opens with "Identify structure 1" and runs to 14 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