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🌍 MRCS Part A · subject
MRCS Part A Physiology Syllabus
Every chapter and topic of Physiology examined in MRCS Part A — 10 chapters, 43 topics and 105 sub-topics, plus 52 flashcards written against it.
Physiology syllabus — full chapter and topic list
Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Physiology in MRCS Part A, not a summary of it.
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Cell Physiology
3 topics- Cell Structure
- Cell Membrane
- Cytoplasm
- Nucleus
- Cell Functions
- Transport Mechanisms
- Cell Signaling
- Cell Division
- Membrane Potential
- Resting Membrane Potential
- Action Potential
- Cell Structure
-
Blood and Immune System
4 topics- Blood Composition
- Plasma
- Blood Cells
- Hemostasis
- Coagulation Cascade
- Platelet Function
- Immune Response
- Innate Immunity
- Adaptive Immunity
- Blood Groups
- ABO System
- Rh System
- Blood Composition
-
Cardiovascular System
4 topics- Heart Anatomy
- Chambers of the Heart
- Heart Valves
- Cardiac Cycle
- Phases of Cardiac Cycle
- Heart Sounds
- Electrophysiology
- Cardiac Action Potential
- Electrocardiogram (ECG)
- Hemodynamics
- Blood Pressure
- Blood Flow
- Heart Anatomy
-
Respiratory System
4 topics- Respiratory Anatomy
- Upper Respiratory Tract
- Lower Respiratory Tract
- Mechanics of Breathing
- Inspiration
- Expiration
- Gas Exchange
- Alveolar Gas Exchange
- Transport of Gases
- Regulation of Respiration
- Neural Regulation
- Chemical Regulation
- Respiratory Anatomy
-
Nervous System
5 topics- Neuroanatomy
- Central Nervous System
- Peripheral Nervous System
- Neurophysiology
- Synaptic Transmission
- Neurotransmitters
- Sensory Systems
- Somatosensory System
- Visual System
- Auditory System
- Olfactory System
- Gustatory System
- Motor Systems
- Motor Cortex
- Basal Ganglia
- Cerebellum
- Autonomic Nervous System
- Sympathetic Nervous System
- Parasympathetic Nervous System
- Neuroanatomy
-
Endocrine System
6 topics- Hormone Classification
- Peptide Hormones
- Steroid Hormones
- Amino Acid Derivatives
- Hypothalamus and Pituitary Gland
- Hypothalamic Hormones
- Pituitary Hormones
- Thyroid Gland
- Thyroid Hormones
- Regulation of Thyroid Function
- Adrenal Glands
- Adrenal Cortex
- Adrenal Medulla
- Pancreas
- Insulin
- Glucagon
- Reproductive Hormones
- Male Reproductive Hormones
- Female Reproductive Hormones
- Hormone Classification
-
Renal System
4 topics- Kidney Anatomy
- Nephron Structure
- Renal Blood Flow
- Urine Formation
- Glomerular Filtration
- Tubular Reabsorption
- Tubular Secretion
- Fluid and Electrolyte Balance
- Water Balance
- Electrolyte Balance
- Acid-Base Balance
- Buffer Systems
- Respiratory Regulation
- Renal Regulation
- Kidney Anatomy
-
Digestive System
4 topics- Gastrointestinal Tract Anatomy
- Mouth and Esophagus
- Stomach
- Small Intestine
- Large Intestine
- Digestive Processes
- Ingestion
- Propulsion
- Mechanical Digestion
- Chemical Digestion
- Absorption
- Defecation
- Accessory Digestive Organs
- Liver
- Pancreas
- Gallbladder
- Regulation of Digestion
- Neural Regulation
- Hormonal Regulation
- Gastrointestinal Tract Anatomy
-
Musculoskeletal System
4 topics- Muscle Physiology
- Skeletal Muscle
- Cardiac Muscle
- Smooth Muscle
- Mechanics of Muscle Contraction
- Sliding Filament Theory
- Neuromuscular Junction
- Bone Physiology
- Bone Structure
- Bone Remodeling
- Joints and Movement
- Types of Joints
- Joint Movements
- Muscle Physiology
-
Special Senses
5 topics- Vision
- Anatomy of the Eye
- Phototransduction
- Visual Pathways
- Hearing
- Anatomy of the Ear
- Mechanics of Hearing
- Auditory Pathways
- Taste
- Taste Buds
- Taste Pathways
- Smell
- Olfactory Epithelium
- Olfactory Pathways
- Equilibrium
- Vestibular Apparatus
- Balance Pathways
- Vision
Physiology flashcards for MRCS Part A
22 of 52 cards from the Physiology deck — real questions with worked answers.
What is the fluid mosaic model of the cell membrane?
A phospholipid bilayer (~$7.5\,\text{nm}$ thick) in which proteins float freely; the bilayer is amphipathic with hydrophilic phosphate heads facing outward and hydrophobic fatty-acid tails facing inward. Cholesterol modulates fluidity.
Which organelle is the site of oxidative phosphorylation and ATP production?
The mitochondrion. Its inner membrane cristae house the electron transport chain and ATP synthase; the matrix contains enzymes of the Krebs cycle.
Contrast rough and smooth endoplasmic reticulum functions.
Rough ER (ribosome-studded) synthesizes and folds secretory/membrane proteins. Smooth ER synthesizes lipids and steroids, stores $\ce{Ca^2+}$, and detoxifies drugs.
What is the role of the Golgi apparatus?
Post-translational modification (e.g. glycosylation), sorting, and packaging of proteins into vesicles for secretion or delivery to lysosomes/membrane.
Define active transport and give the key example in cells.
Movement of solute against its electrochemical gradient using energy (ATP). Example: the $\ce{Na+/K+}$-ATPase pump, which extrudes $3\,\ce{Na+}$ out and imports $2\,\ce{K+}$ per ATP hydrolysed.
Distinguish primary from secondary active transport.
Primary active transport directly uses ATP (e.g. $\ce{Na+/K+}$-ATPase). Secondary active transport uses the electrochemical gradient set up by a primary pump (e.g. $\ce{Na+}$-glucose symport, SGLT1).
State the Nernst equation for the equilibrium potential of an ion.
$$E_{ion}=\frac{RT}{zF}\ln\frac{[\text{ion}]_{out}}{[\text{ion}]_{in}}$$ At $37^{\circ}\text{C}$ for a monovalent cation this simplifies to $E=61\log_{10}\frac{[\text{ion}]_{out}}{[\text{ion}]_{in}}\ \text{mV}$.
What is the typical resting membrane potential of a neuron and what mainly sets it?
About $-70\,\text{mV}$. It is set mainly by the high resting permeability to $\ce{K+}$ (approaching $E_K\approx-90\,\text{mV}$) maintained by the $\ce{Na+/K+}$-ATPase.
Describe the phases of a neuronal action potential.
Depolarization from $\ce{Na+}$ influx (voltage-gated $\ce{Na+}$ channels open at threshold $\approx-55\,\text{mV}$), repolarization from $\ce{K+}$ efflux, then a hyperpolarizing undershoot before return to rest. It is all-or-none.
What is the approximate composition of blood by volume?
Plasma $\approx55\%$, formed elements $\approx45\%$ (mostly erythrocytes; the buffy coat of leucocytes and platelets is $<1\%$). Normal haematocrit is roughly $0.40\text{--}0.54$ (male) and $0.36\text{--}0.46$ (female).
List the plasma proteins and their main roles.
Albumin (main oncotic pressure, $\sim60\%$), globulins (immune/transport), and fibrinogen (clotting). Total plasma protein $\approx60\text{--}80\,\text{g/L}$.
What is the normal lifespan and fate of a red blood cell?
About $120$ days. Senescent RBCs are removed by macrophages of the reticuloendothelial system (spleen, liver); haem is broken down to bilirubin and iron is recycled.
Name the two pathways of the coagulation cascade and their converging point.
Intrinsic (contact) pathway and extrinsic (tissue factor) pathway. They converge at activation of factor X to form the common pathway, generating thrombin and then fibrin.
What are the three steps of primary hemostasis?
1) Vasoconstriction of the injured vessel; 2) platelet adhesion (via von Willebrand factor to collagen); 3) platelet activation and aggregation forming the primary platelet plug.
What is the role of vitamin K in coagulation?
It is a cofactor for $\gamma$-carboxylation of factors II, VII, IX and X (and proteins C and S), enabling their $\ce{Ca^2+}$-dependent binding to phospholipid surfaces. Warfarin inhibits this.
Which laboratory tests assess the intrinsic and extrinsic pathways?
APTT (activated partial thromboplastin time) assesses the intrinsic/common pathway; PT (prothrombin time, reported as INR) assesses the extrinsic/common pathway.
Describe the two arms of the adaptive immune response.
Humoral immunity — B lymphocytes producing antibodies against extracellular pathogens; and cell-mediated immunity — T lymphocytes ($\ce{CD4+}$ helper and $\ce{CD8+}$ cytotoxic) targeting intracellular pathogens and infected cells.
Differentiate innate from adaptive immunity.
Innate immunity is rapid, non-specific, has no memory (barriers, phagocytes, complement, NK cells). Adaptive immunity is slower, antigen-specific, and generates immunological memory (T and B lymphocytes).
What is the sequence of antibody classes in a primary vs secondary response?
Primary response: IgM appears first, then IgG. Secondary response: rapid, larger, predominantly high-affinity IgG owing to memory B cells.
What is the ABO blood group system and its antigen/antibody pattern?
Group A has A antigen + anti-B; group B has B antigen + anti-A; group AB has both antigens + no antibodies (universal recipient); group O has no antigen + anti-A and anti-B (universal donor).
Explain Rhesus (RhD) incompatibility in pregnancy.
An RhD-negative mother sensitized to RhD-positive fetal cells produces anti-D IgG, which crosses the placenta in a subsequent RhD-positive pregnancy causing haemolytic disease of the newborn. Prevented by anti-D prophylaxis.
Which blood group is the universal donor for packed red cells and why?
Group O RhD-negative — its red cells carry neither A/B nor D antigens, so they are not agglutinated by recipient anti-A, anti-B or anti-D antibodies.
Planning Physiology for MRCS Part A
Physiology is about 18% of the MRCS Part A syllabus by topic count — 43 of 236 topics, spread over 10 chapters. At roughly 45 minutes per topic plus 12 minutes per sub-topic, a first pass runs to about 55 hours.
The heaviest chapters are Endocrine System (6 topics), Nervous System (5 topics), Special Senses (5 topics) . Front-load those while your energy is high; the short chapters are better revision filler later.
Work top-down: read the chapter, then tick topics off individually rather than marking the whole chapter done. Sub-topics are where silent gaps hide.
Physiology (MRCS Part A) FAQ
What is in the MRCS Part A Physiology syllabus?
Physiology is split into 10 chapters — Cell Physiology, Blood and Immune System, Cardiovascular System, Respiratory System, Nervous System and Endocrine System, and 4 more, containing 43 topics and 105 sub-topics in total.
How many chapters are there in Physiology for MRCS Part A?
10 chapters. Physiology accounts for about 18% of the topics in the whole MRCS Part A syllabus (43 of 236).
How long should I spend on Physiology for MRCS Part A?
Budget around 55 hours for a first pass through Physiology — about 45 minutes per topic plus 12 minutes per sub-topic across its 43 topics. Add revision cycles on top.
Are there flashcards for MRCS Part A Physiology?
Yes — a 52-card Physiology deck. Sample cards are printed on this page, and the full deck is free in the Examius app with spaced repetition scheduling.