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218 notes
USMLE · drawn around the anatomy
Anatomy one-pagers
One-pager
Coronary arteries and ECG territories
USMLE Step 1
Renal & acid–base
EP 01
ABG interpretation, made simple
EP 02
Anion gap explained: high vs normal gap metabolic acidosis
EP 03
Winters' formula: the expected PaCO₂ in metabolic acidosis
EP 04
Delta ratio: find the hidden second acid–base disorder
EP 05
New bicarbonate: how the kidney excretes acid with ammonium
EP 06
High anion gap metabolic acidosis causes, sorted by the anion
EP 07
Osmolar gap: how toxic alcohols hide from the anion gap
EP 08
Urine anion gap: telling diarrhea from RTA
EP 09
Renal tubular acidosis: tell RTA types 1, 2 and 4 apart
EP 10
Metabolic alkalosis: generation, maintenance and urine chloride
EP 11
Vomiting metabolic alkalosis: why the urine turns acid
EP 12
Bartter vs Gitelman: NKCC2, NCC and urine calcium
EP 13
Respiratory acidosis compensation: acute vs chronic
EP 14
Respiratory alkalosis compensation: acute vs chronic
EP 15
Metabolic alkalosis compensation: the expected PaCO₂
EP 16
Salicylate poisoning acid-base: a classic mixed disorder
EP 17
Type A vs type B lactic acidosis: split it by mechanism
EP 18
DKA anion gap explained: from high gap to hyperchloraemic acidosis
EP 19
Acidosis and hyperkalemia: how pH shifts potassium
EP 20
ABG interpretation in 6 steps: the acid-base algorithm
EP 21
Acid-base practice cases: three ABG vignettes, one algorithm
USMLE Step 1
Renal physiology
EP 01
GFR and Starling forces at the glomerulus
EP 02
Afferent vs efferent arteriole: GFR, RPF and filtration fraction
EP 03
Renal clearance: inulin, creatinine and PAH
EP 04
Glucose transport maximum, splay and SGLT2
EP 05
Countercurrent multiplier: how the kidney concentrates urine
EP 06
Aldosterone and ADH in the distal nephron
EP 07
Diuretics by nephron segment: loop, thiazide and more
EP 08
RAAS explained: renin, angiotensin II and aldosterone
USMLE Step 1
Cardiovascular physiology
EP 01
Pressure-volume loop explained: four phases, four valve events
EP 02
Preload on the pressure-volume loop: EDV, stroke volume and the EDPVR
EP 03
Afterload on the pressure-volume loop
EP 04
Contractility on the pressure-volume loop: the ESPVR explained
EP 05
Wiggers diagram explained: the cardiac cycle step by step
EP 06
The Frank-Starling curve: preload, inotropy and heart failure
EP 07
Aortic stenosis vs mitral regurgitation on the pressure-volume loop
EP 08
Fick principle: how to calculate cardiac output
EP 09
HFrEF vs HFpEF on the pressure-volume loop
EP 10
Poiseuille's law and vascular resistance: why arterioles matter
EP 11
Venous return and cardiac function curves: where they cross
EP 12
The baroreceptor reflex: from stretch to vagal and sympathetic output
EP 13
Myocardial oxygen supply and demand: why tachycardia causes ischaemia
EP 14
Unstable angina vs NSTEMI vs STEMI: from plaque to ACS
EP 15
Antianginal drugs: nitrates, beta blockers, calcium channel blockers
EP 16
Complications of myocardial infarction, by timeline
USMLE Step 1
Heart sounds, murmurs and ECG
EP 01
S2 splitting and heart sounds S1–S4, explained
EP 02
Heart murmurs and dynamic manoeuvres, from preload and afterload
EP 03
HOCM vs aortic stenosis murmur: telling them apart at the bedside
EP 04
Ventricular action potential: phases 0 to 4 and their ion currents
EP 05
SA node pacemaker potential: phase 4 sets the heart rate
EP 06
ECG waves and intervals: what P, PR, QRS, ST and QT mean
USMLE Step 1
Respiratory physiology
EP 01
Lung volumes and capacities, explained
EP 02
Obstructive vs restrictive lung disease: FEV1/FVC and loops
EP 03
Lung compliance, Laplace and surfactant: why alveoli stay open
EP 04
V/Q mismatch: shunt, dead space and the oxygen test
EP 05
A-a gradient: the alveolar gas equation and the causes of hypoxaemia
EP 06
Oxygen-hemoglobin dissociation curve: P50, shifts and content
EP 07
CO₂ transport: bicarbonate, the chloride shift, Bohr vs Haldane
EP 08
Central vs peripheral chemoreceptors and oxygen-induced hypercapnia
EP 09
Hypoxic pulmonary vasoconstriction and cor pulmonale
EP 10
CO, cyanide and methaemoglobin: why SpO₂ and PaO₂ fool you
USMLE Step 1
Neuroanatomy and lesion localisation
EP 01
Upper vs lower motor neuron lesions: signs and localisation
EP 02
Dorsal column vs spinothalamic tract: where each pathway crosses
EP 03
Spinal cord syndromes compared: rebuild each from three tracts
EP 04
Cranial nerve nuclei: a brainstem map by level and position
EP 05
Brainstem crossed findings: the localisation rule
EP 06
Medial vs lateral medullary syndrome: artery, structures and signs
EP 07
Facial nerve palsy: why the forehead tells you the lesion
EP 08
Stroke syndromes by artery: ACA, MCA and PCA
EP 09
Lacunar stroke syndromes: pure motor, pure sensory and more
EP 10
Visual pathway lesions and field defects
EP 11
Basal ganglia direct and indirect pathways: D1, D2 and movement
EP 12
Cerebellar lesion localisation: vermis vs hemisphere
EP 13
Brain herniation syndromes: what is squeezed, and where
EP 14
CSF flow and hydrocephalus: where the flow fails
EP 15
Corticospinal tract: from cortex to anterior horn
EP 16
Hypothalamic nuclei and their functions
USMLE Step 1
Immunology
EP 01
MHC I vs MHC II: how antigen presentation works
EP 02
T-cell activation: the two-signal model
EP 03
Th1, Th2, Th17 and Treg: helper T-cell subsets
EP 04
Antibody isotypes and class switching
EP 05
Central vs peripheral tolerance: how lymphocytes learn self-tolerance
EP 06
Complement system explained: three pathways, one ending
EP 07
Complement deficiencies: C1q, C3, C5–C9 and C1 inhibitor
EP 08
Hypersensitivity types I to IV: the four effectors
EP 09
B-cell vs T-cell immunodeficiency: predict the infections
EP 10
Hyper IgM syndrome: CD40 ligand and class switching
EP 11
Chronic granulomatous disease: NADPH oxidase and the respiratory burst
EP 12
Leukocyte adhesion deficiency: CD18 and neutrophil extravasation
EP 13
Transplant rejection explained: hyperacute, acute, chronic and GVHD
EP 14
Vaccine types explained: live, inactivated, conjugate and mRNA
USMLE Step 1
Pharmacology: principles and autonomic drugs
EP 01
Potency vs efficacy: EC50, Emax and agonist types
EP 02
Competitive vs noncompetitive antagonists: effect on EC50 and Emax
EP 03
Therapeutic index explained: TD50 / ED50
EP 04
First-pass metabolism and bioavailability: calculating oral F from AUC
EP 05
Volume of distribution: why Vd can be bigger than the body
EP 06
Clearance and half-life: t½ = 0.693 × Vd / CL
EP 07
Zero-order vs first-order elimination explained
EP 08
Loading dose and maintenance dose, explained
EP 09
CYP450 inducers and inhibitors: how they change drug levels
EP 10
Autonomic receptors: alpha, beta and muscarinic
EP 11
Beta blocker selectivity: beta-1, ISA and alpha blockade
EP 12
Vasopressors compared: receptors, pressure and heart rate
EP 13
Organophosphate poisoning: muscarinic vs nicotinic signs
EP 14
Receptor desensitization, downregulation and upregulation
EP 15
Beta-lactams and vancomycin: enzyme versus substrate
EP 16
Protein synthesis inhibitors: 30S vs 50S antibiotics
USMLE Step 1
Endocrinology
EP 01
Hypothalamic-pituitary axes and feedback: primary, secondary, tertiary
EP 02
Primary vs secondary endocrine disorders: paired hormone levels
EP 03
Insulin secretion in the beta cell: from glucose to granule
EP 04
Insulin vs glucagon signalling: receptors and effects
EP 05
DKA vs HHS pathophysiology: why only one makes acid
EP 06
Diabetes drugs by mechanism: where each class acts
EP 07
Thyroid hormone synthesis, step by step
EP 08
Calcium homeostasis: PTH, vitamin D and calcitonin
EP 09
Adrenal steroidogenesis: zones, enzymes and the 17α-hydroxylase fork
EP 10
Congenital adrenal hyperplasia: three enzymes, three patterns
EP 11
Cushing syndrome: the dexamethasone suppression test and ACTH
EP 12
Primary hyperaldosteronism: high aldosterone, low renin
EP 13
SIADH vs diabetes insipidus: central vs nephrogenic DI
EP 14
MEN1, MEN2A and MEN2B: match the gene to its tumours
USMLE Step 1
Haematology and oncology
EP 01
Microcytic anaemia: four causes, four iron fingerprints
EP 02
Hepcidin: why iron falls in inflammation
EP 03
B12 vs folate deficiency: MMA, homocysteine and the nerves
EP 04
Intravascular vs extravascular haemolysis: site and labs
EP 05
G6PD deficiency vs hereditary spherocytosis, by mechanism
EP 06
Sickle cell disease pathophysiology: HbS to vaso-occlusion
EP 07
Primary haemostasis: platelet adhesion, activation and aggregation
EP 08
Coagulation cascade: PT vs aPTT, pathway by pathway
EP 09
Von Willebrand disease vs haemophilia: the labs that separate them
EP 10
Anticoagulants: target, monitoring test and reversal agent
EP 11
Heparin-induced thrombocytopenia: why a low count clots
EP 12
DIC vs TTP vs HUS: mechanism and the PT/PTT
EP 13
AML vs ALL vs CML vs CLL: leukemia classification made simple
EP 14
Oncogenes vs tumour suppressor genes: one hit or two
USMLE Step 1
Microbiology
EP 01
Gram-positive vs gram-negative cell walls
EP 02
Acid-fast stain and the mycobacterial cell wall
EP 03
Endotoxin vs exotoxin: lipid A, A-B toxins and toxoids
EP 04
Bacterial toxins that raise cAMP: cholera, pertussis, anthrax
EP 05
Clostridial toxins compared: tetanus, botulinum, alpha, C. difficile
EP 06
Staph vs strep: catalase, coagulase and haemolysis
EP 07
Encapsulated organisms and the spleen: asplenia and conjugate vaccines
EP 08
Bacterial genetics: how bacteria swap genes
EP 09
Beta-lactamase and antibiotic resistance: three ways bacteria win
EP 10
DNA vs RNA virus replication: which enzyme each genome needs
EP 11
HIV life cycle and drug targets, step by step
EP 12
Hepatitis B serology: reading the panel
EP 13
Antifungal drugs explained: mechanisms of action
EP 14
Bacterial meningitis organisms by age and risk group
USMLE Step 1
GI physiology and pathology
USMLE Step 2 CK
Emergency medicine
A-level Biology
3.1 Biological molecules
EP 01
Condensation and Hydrolysis Reactions
EP 02
Maltose, Sucrose, Lactose: Glycosidic Bonds
EP 03
Alpha vs Beta Glucose: Starch vs Cellulose
EP 04
Benedict's and Iodine Tests Explained
EP 05
Triglycerides: Saturated vs Unsaturated Fats
EP 06
Phospholipids vs Triglycerides: Emulsion Test
EP 07
Amino Acids and Peptide Bonds Explained
EP 08
Protein Structure: Primary to Quaternary
EP 09
Globular vs Fibrous Proteins and Biuret Test
EP 10
How Enzymes Work: Active Site and Induced Fit
EP 11
Enzymes: Temperature and pH Effects
EP 12
Enzyme Rate Graphs: Why the Plateau
EP 13
Competitive vs Non-Competitive Inhibitors
EP 14
Required Practical 1: Enzyme Rates
EP 15
DNA and RNA Nucleotides: Structure Compared
EP 16
DNA Double Helix and Phosphodiester Bonds
EP 17
DNA Replication: Helicase and Polymerase
EP 18
Meselson and Stahl Experiment Explained
EP 19
ATP: Structure, Hydrolysis and Resynthesis
EP 20
Water: Five Properties Linked to Function
EP 21
Inorganic Ions and Their Roles
A-level Biology
3.2 Cells
EP 22
Nucleus, Mitochondria and Chloroplasts
EP 23
Rough ER, Golgi and Lysosomes Explained
EP 24
Cell Wall, Vacuole and Specialised Cells
EP 25
Prokaryotic vs Eukaryotic Cells
EP 26
Viruses: Structure and Non-Living Status
EP 27
Optical, TEM and SEM Microscopes Compared
EP 28
Magnification vs Resolution Calculations
EP 29
Cell Fractionation and Ultracentrifugation
EP 30
Mitosis and the Cell Cycle: Stages
EP 31
Cancer: Uncontrolled Cell Division
EP 32
Binary Fission and Virus Replication
EP 33
Required Practical 2: Root Tip Squash
EP 34
Fluid-Mosaic Model: Cell Membrane Structure
EP 35
Simple vs Facilitated Diffusion
EP 36
Osmosis and Water Potential Explained
EP 37
Active Transport and Co-transport (Ileum)
EP 38
Why Cells Transport Faster: Microvilli
EP 39
Required Practical 3: Water Potential
EP 40
Required Practical 4: Membrane Permeability
EP 41
Antigens and Cell Recognition
EP 42
Phagocytosis: How Phagocytes Work
EP 43
T Lymphocytes: The Cellular Immune Response
EP 44
B Cells, Clonal Selection and Antibodies
EP 45
Primary and Secondary Immune Response
EP 46
Vaccines, Herd Immunity, Active vs Passive
EP 47
HIV Replication and How It Causes AIDS
EP 48
Monoclonal Antibodies in Medicine
EP 49
The ELISA Test Explained
EP 50
Vaccine and Antibody Ethics and Evidence
A-level Biology
3.3 Exchange with the environment
EP 51
Surface Area to Volume Ratio Explained
EP 52
SA:V Ratio, Body Size and Metabolic Rate
EP 53
Gas Exchange: Single Cells and Insects
EP 54
Fish Gills and the Counter-current Principle
EP 55
Gas Exchange in Leaves: Mesophyll and Stomata
EP 56
Gas Exchange vs Water Loss: Xerophytes
EP 57
Human Gas Exchange System and Alveoli
EP 58
Ventilation: How Breathing Works
EP 59
Lung Disease and Gas Exchange
EP 60
Smoking, Pollution and Lung Disease Data