MRCS Part A

# 21 HEAD INJURY Head injury is one of the highest-yield topics in MRCS Part A — expect three to five questions per paper. Questions are predictable in shape: a GCS calculation, a NICE-criteria triage question, a CT image pattern (lens vs crescent), and a physiology question on intracranial pressure

# 25 RAAS The renin-angiotensin-aldosterone system (RAAS) is the body's long-term regulator of blood pressure, sodium balance and extracellular fluid volume — and the most heavily examined endocrine cascade in MRCS Part A. Every step has a drug acting on it, and every drug has a side

# 24 ADRENERGIC RECEPTORS 👩‍⚕️ Adrenergic pharmacology is one of the highest-yield MRCS Part A topics. Every question collapses to the same logic: identify the receptor, its location, predict the effect. What are adrenergic receptors? G-protein coupled receptors activated by noradrenaline, adrenaline and dopamine. Five clinically relevant subtypes, each defined

👩‍⚕️ MRCS Tip: Renal transport is one of the most reliably examined physiology topics in Part A. If you can map each nephron segment to (a) what it absorbs, (b) which transporter does the work, and (c) which diuretic blocks it, you will pick up easy marks every sitting. How the

👩‍⚕️ The airway is the first letter of ATLS for a reason — hypoxic brain injury starts within minutes. Learn the landmarks cold: the cricothyroid membrane (between thyroid and cricoid cartilages) is your emergency front-of-neck access, and the cricoid is the only complete cartilage ring — the anchor for almost every

Detailed notes For MRCS Part A you are not tested on lymph physiology in detail — you are tested on which nodes drain which organ, because that determines where cancers metastasise and where surgeons must dissect. Two principles unlock most questions: 1. Lymphatics follow arteries — drainage of a gut segment mirrors

# 29 INTERPRETING BLOOD GASES ABG interpretation is one of the highest-yield skills in MRCS Part A. A single set of numbers can test physiology, pharmacology, surgical pathology and clinical reasoning at once — but every ABG is solved by the same five-step algorithm. Learn it cold. Normal values ParameterNormal

👩‍⚕️ Thyroid is one of the most heavily examined organs in MRCS Part A. Examiners love it because it links anatomy (recurrent laryngeal nerve, parathyroids, blood supply), physiology (TSH–T4–T3 axis), pathology (autoimmune disease, four cancers with distinct biology) and surgery (four classic post-thyroidectomy complications). Master those four axes

# 31 NECK LUMPS Neck lumps are an examiner's playground. They reward candidates who can map a clinical sign to an anatomical compartment, then collapse the differential by age and behaviour of the lump. The trick is not memorising every lesion — it is having a reproducible system: where is

# 33 OTOLARYNGOLOGY ENT comes up reliably in MRCS Part A because it sits at the crossroads of head and neck anatomy, embryology, microbiology and acute surgical management. This chapter teaches the topic the way examiners test it: anatomy first, then the conditions, then the SBAs. Detailed notes Anatomy of the