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Pathophysiology

How disease changes the body.

Follow each condition from healthy function, through the change that goes wrong, to the symptoms it causes. Step by step, in 3D and diagrams.

  • 214conditions across 12 body systems
  • 32shared mechanisms they build on
  • 2422self-check questions
  • 245lessons with a 3D scene

Browse by body system

246 lessons

Shared mechanisms

The processes most diseases are built from: cell injury, deposits and adaptations, inflammation, repair, circulation, clotting, fluid balance, shock, feedback, genetics and how pathologists diagnose.

  1. PH-FD01Cell injury and hypoxiaHow oxygen reaches the mitochondria to make ATP, what fails when it does not arrive, and why early hypoxic injury can recover while prolonged injury breaks membranes and kills the cell.6 steps · 10 questions · 3D anatomy
  2. PH-FD02Apoptosis and necrosisTwo ways a cell dies: apoptosis, a controlled shrinking that removes cells quietly, and necrosis, a swelling and bursting that inflames the tissue, with the patterns necrosis takes in different organs.6 steps · 10 questions · 3D anatomy
  3. PH-FD03Acute and chronic inflammationHow injured tissue calls in fluid and white cells: why vessels dilate and leak, how neutrophils leave the blood, which mediators cause the cardinal signs, and what happens when inflammation persists.7 steps · 10 questions · 3D anatomy
  4. PH-FD04Repair and fibrosisHow tissues heal after injury: when lost cells can be replaced like for like, how granulation tissue and collagen build a scar, and how repair that does not stop becomes fibrosis that stiffens organs.7 steps · 10 questions · 3D disease scene
  5. PH-FD05Thrombosis and embolismWhy blood that should stay fluid clots inside a vessel, why arterial and venous thrombi differ, and where a fragment that breaks free travels and lodges.7 steps · 10 questions · 3D disease scene
  6. PH-FD06Oedema and fluid movementHow fluid moves between capillaries, tissues and lymphatics, and the four ways the balance fails: raised capillary pressure, low plasma protein, leaky vessels and blocked lymph drainage.7 steps · 10 questions · 3D anatomy
  7. PH-FD07ShockShock is circulatory failure that leaves cells short of oxygen. This lesson explains its four mechanisms, how the body compensates, and how prolonged hypoperfusion injures cells and organs.6 steps · 10 questions · 3D anatomy
  8. PH-FD08Acid-base disturbancesHow buffers, the lungs and the kidneys keep blood pH steady, what goes wrong in the four primary acid-base disorders, how the body compensates and why an abnormal pH affects potassium, calcium, the heart and the brain.7 steps · 10 questions · 3D anatomy
  9. PH-FD09Electrolyte disturbancesWhy a sodium disorder is really a water disorder, how potassium and calcium set the excitability of nerves and heart muscle, and why the speed of an electrolyte change matters as much as its size.7 steps · 10 questions · 3D anatomy
  10. PH-FD10Hormone feedbackHow the hypothalamus, pituitary and target glands regulate one another through negative feedback, and how paired hormone levels show whether a disorder starts in the gland, the pituitary or outside the axis.6 steps · 10 questions · 3D anatomy
  11. PH-FD11Intracellular accumulationsWhy cells fill with water, fat, protein or glycogen: the four routes to an accumulation, what fatty change and storage diseases look like, and when a build-up is harmless, reversible or the start of lasting damage.7 steps · 10 questions · 3D disease scene
  12. PH-FD12Endogenous and exogenous pigmentsWhere the colours in tissues come from: melanin from melanocytes, haemosiderin and bilirubin from broken-down haemoglobin, lipofuscin from ageing cells, and carbon, ink and metals from outside, with what each looks like and causes.7 steps · 10 questions · 3D anatomy
  13. PH-FD13Pathological calcificationWhy calcium salts settle in soft tissue: dystrophic calcification in dead or damaged tissue with normal blood calcium, metastatic calcification in normal tissue when calcium or phosphate is high, and what each looks like and does.6 steps · 10 questions · 3D disease scene
  14. PH-FD14Hyaline change (hyalinosis)Why some tissues turn glassy and pink: hyaline as an appearance, not one substance, and its main forms, from thickened arterioles in hypertension and diabetes to hyaline membranes in injured lungs, with the harm each does.7 steps · 10 questions · 3D disease scene
  15. PH-FD15How stones formWhy substances dissolved in urine, bile and saliva can turn into stones: supersaturation, crystal nucleation, growth and retention, the main types of stone, and what a stone does to the duct or organ that holds it.7 steps · 10 questions · 3D disease scene
  16. PH-FD16AmyloidosisHow misfolded proteins stack into insoluble fibrils that collect between cells: where the precursor proteins come from, the main types, how amyloid is recognised under the microscope, and why it stiffens the heart and makes the kidneys leak protein.7 steps · 10 questions · 3D anatomy
  17. PH-FD17AtrophyWhy cells and organs shrink when use, nerve supply, blood supply, hormones or nutrition fall: how a cell digests its own proteins, the main causes of atrophy, what atrophic organs look like and when the change can reverse.7 steps · 10 questions · 3D anatomy
  18. PH-FD18Hypertrophy and hyperplasiaHow tissues answer more work or more growth signals: by enlarging their cells (hypertrophy), by making more cells (hyperplasia) or both; why the heart can only enlarge its cells, and when growth becomes harmful.7 steps · 10 questions · 3D anatomy
  19. PH-FD19Metaplasia and dysplasiaHow chronic injury makes a lining change its cell type (metaplasia), what the new lining gains and loses, and how disordered, atypical growth (dysplasia) marks the road from a changed lining towards carcinoma.7 steps · 10 questions · 3D disease scene
  20. PH-FD20Serous, fibrinous and catarrhal inflammationWhy inflamed tissue leaks thin serous fluid, sticky fibrin or mucus-laden catarrh: how vessel injury and the surface involved decide which, what each looks like, and how each clears or scars.7 steps · 10 questions · 3D anatomy
  21. PH-FD21Purulent inflammationHow pus forms: why pyogenic bacteria draw in floods of neutrophils, how neutrophil enzymes liquefy tissue, and why pus walls off as an abscess, spreads as phlegmon or fills a cavity as empyema, and how it heals or spreads.7 steps · 10 questions · 3D anatomy
  22. PH-FD22Haemorrhagic and gangrenous inflammationWhy some inflammations fill with blood and others rot: how toxins and severe vessel injury let red cells into the exudate, and how anaerobic bacteria turn dead, poorly supplied tissue into foul, gas-filled gangrene.7 steps · 10 questions · 3D anatomy
  23. PH-FD23Chronic specific (granulomatous) inflammationWhy macrophages wall off what they cannot destroy: how T cells turn them into the epithelioid and giant cells of a granuloma, how the types differ, and what tuberculosis, leprosy and syphilis teach about immunity.7 steps · 10 questions · 3D disease scene
  24. PH-FD24Injury from physical agentsHow physical energy damages tissue: force scrapes, tears and cuts, heat coagulates proteins, cold freezes cells and injures vessels, electric current heats the tissues it crosses, and ionising radiation breaks DNA in dividing cells.7 steps · 10 questions · 3D anatomy
  25. PH-FD25Venous congestion (hyperaemia)Why blood pools when it cannot drain: how raised venous pressure distends capillaries, drives fluid into tissues and starves cells of oxygen, and how chronic congestion browns the lung, mottles the liver and stains the legs.7 steps · 10 questions · 3D anatomy
  26. PH-FD26IschaemiaWhat happens when arterial inflow falls short of a tissue’s needs: why flow falls, why some tissues and zones suffer first, how speed of onset and collaterals decide the outcome, and why narrowed arteries cause pain on exertion.6 steps · 10 questions · 3D anatomy
  27. PH-FD27InfarctionHow a blocked vessel kills a territory of tissue: why some infarcts are pale and others red, why they are wedge-shaped, how an infarct changes from hours to months, and how infarcts differ in the heart, brain, lung, kidney, spleen and bowel.6 steps · 10 questions · 3D anatomy
  28. PH-FD28HaemorrhageHow blood escapes from vessels: through a tear, an eroded wall or leaky small vessels; how bleeds are named by size and site; why volume, speed and site decide the danger; and what happens to blood left in the tissues.7 steps · 10 questions · 3D anatomy
  29. PH-FD29Developmental malformationsHow organs are built in weeks 3 to 8 after fertilisation, how genes, teratogens or both derail that programme, why timing decides the defect, and how one malformation can cascade into others.7 steps · 10 questions · 3D anatomy
  30. PH-FD30Autosomal dominant and recessive disordersHow a change in one gene causes disease: why one altered copy is enough in dominant disorders and two are needed in recessive ones, the family patterns and chances that follow, and sickle cell disease as a worked example.6 steps · 10 questions · 3D anatomy
  31. PH-FD31Chromosomal disordersHow errors in the number or structure of chromosomes arise, mostly when eggs and sperm form, why an extra or missing chromosome disturbs so many organs, and the main syndromes, from trisomy 21 to Turner and Klinefelter syndromes.6 steps · 10 questions · 3D anatomy
  32. PH-FD32How pathologists make a diagnosisHow a diagnosis is made from tissue, cells and the whole body: the kinds of sample, how tissue becomes a stained slide, how a pathologist reads it against normal structure, and the extra stains and tests that classify disease.7 steps · 10 questions · 3D anatomy

Cardiovascular

Arteries, the heart muscle, valves, rhythm and veins.

  1. PH-CV01AtherosclerosisHow lipid and inflammation build a plaque in the wall of an artery, why a fixed narrowing causes pain on exertion, and why a ruptured plaque blocks the artery suddenly.7 steps · 10 questions · 3D disease scene
  2. PH-CV02Myocardial infarctionHow a blocked coronary artery starves a territory of heart muscle, why the inner wall dies first, and how lost muscle, healing and scarring explain the symptoms and the complications that can follow.7 steps · 10 questions · 3D disease scene
  3. PH-CV03Heart failureHow a heart that contracts weakly or fills poorly lowers output, why the body’s own responses add to the load, and how left- and right-sided congestion explain breathlessness and swelling.7 steps · 10 questions · 3D anatomy
  4. PH-CV04HypertensionHow cardiac output and arteriolar resistance set blood pressure, why it stays high in essential and secondary hypertension, and how remodelled small vessels and a thickened heart lead to damage in the heart, brain, kidneys and eyes.6 steps · 10 questions · 3D anatomy
  5. PH-CV05Atrial fibrillationHow disorganised electrical activity replaces the sinus rhythm, why the ventricles beat irregularly, what losing the atrial kick costs, and why stasis in the left atrial appendage can lead to a stroke.6 steps · 10 questions · 3D anatomy
  6. PH-CV06Valve stenosis and regurgitationHow heart valves keep blood moving one way, why a narrowed valve loads the heart with pressure and a leaking valve with volume, how the heart adapts and then fails, and how murmurs and symptoms follow from the mechanism.6 steps · 10 questions · 3D anatomy
  7. PH-CV07Deep vein thrombosisHow the calf muscle pump and venous valves return blood from the legs, why stasis, vessel injury and a clotting tendency combine to form a clot in a deep vein, and how that clot causes a swollen leg and can travel to the lungs.6 steps · 10 questions · 3D disease scene
  8. PH-CV08Aortic aneurysm and dissectionHow the elastic wall of the aorta weakens, why a weakened segment balloons and keeps growing until it may rupture, and how a tear in the inner wall lets blood split the layers apart in an aortic dissection.6 steps · 10 questions · 3D disease scene
  9. PH-CV09Tumours of the heartWhy metastases are by far the commonest heart tumours, how a benign left atrial myxoma obstructs, embolises and causes fever, and how fibroelastoma, rhabdomyoma and angiosarcoma differ, with tumour in the pericardium causing tamponade.7 steps · 10 questions · 3D anatomy
  10. PH-CV10Blood and lymphatic vessel tumoursHow tumours of blood and lymphatic vessels range from benign haemangiomas and pyogenic granuloma, through Kaposi sarcoma driven by HHV-8, to angiosarcoma after sun, radiation or lymphoedema, and how they bleed, trap platelets and spread.7 steps · 10 questions · 3D anatomy
  11. PH-CV11Ischaemic heart diseaseHow coronary disease starves the heart in different ways: a fixed narrowing on exertion (stable angina), spasm, a thrombus on a disrupted plaque (acute coronary syndromes), chronic underperfusion and scarring, and sudden cardiac death.7 steps · 10 questions · 3D anatomy
  12. PH-CV12Hypertensive heart diseaseHow a ventricle pumping against high pressure thickens (Laplace), why the thick wall fills poorly, enlarges the atrium and runs short of oxygen, how it can finally dilate, and how lung disease does the same to the right ventricle.7 steps · 10 questions · 3D anatomy
  13. PH-CV13Rheumatic fever and rheumatic heart diseaseHow an immune response to a streptococcal sore throat can inflame every layer of the heart weeks later, why the valves heal by scarring, and how repeated attacks fuse and narrow the mitral valve over years.7 steps · 10 questions · 3D anatomy
  14. PH-CV14Infective and non-infective endocarditisHow damaged valves gather sterile clots that bacteria in the blood colonise, why acute and subacute endocarditis differ, and how vegetations destroy valves, embolise and seed immune complexes to cause the classic signs.8 steps · 10 questions · 3D anatomy
  15. PH-CV15CardiomyopathiesHow faults in the heart muscle itself produce weak, dilated ventricles, thick and obstructed ones, stiff ones that will not fill, a right ventricle that turns to fat and scar, or a heart stunned by stress.8 steps · 9 questions · 3D anatomy
  16. PH-CV16MyocarditisHow viruses, toxins, parasites, medicines and the immune system inflame and kill heart muscle cells, why troponin rises and the ECG changes, and how myocarditis heals, kills suddenly or leaves a dilated, failing heart.7 steps · 9 questions · 3D anatomy
  17. PH-CV17Congenital heart diseaseHow heart defects follow from a septum, shunt or outflow division that failed in development, why pressures after birth decide which way blood crosses, and how shunts, cyanotic lesions and obstructions cause their signs.8 steps · 10 questions · 3D anatomy
  18. PH-CV18Pericarditis and other pericardial diseaseHow inflammation roughens the pericardium and causes pain, a rub and widespread ST elevation, why fluid that gathers fast compresses the heart (tamponade), and how a scarred pericardium constricts filling.6 steps · 10 questions · 3D anatomy
  19. PH-CV19VasculitisHow inflammation of the vessel wall narrows, blocks, weakens or tears vessels, and why the size of vessel affected decides whether it causes blindness, absent pulses, infarcts, aneurysms, purpura or glomerulonephritis.7 steps · 10 questions · 3D anatomy
  20. PH-CV20Varicose veins and chronic venous insufficiencyHow failed valves turn the calf muscle pump against the leg: reflux at the saphenous junctions dilates the superficial veins, and pressure that stays high during walking leaks into the skin, causing oedema, brown staining, hard skin and ulcers.6 steps · 10 questions · 3D anatomy

Respiratory

Airways, alveoli, the pleura and the pulmonary circulation, and lung tumours.

  1. PH-RS01AsthmaHow type 2 inflammation makes the airways narrow too easily, why the narrowing is variable and reversible, why wheeze is loudest on breathing out, and how long-standing asthma can remodel the airway wall.6 steps · 10 questions · 3D disease scene
  2. PH-RS02COPD: emphysema and chronic bronchitisHow smoke and inflammation destroy alveolar walls (emphysema) and inflame mucus-filled airways (chronic bronchitis), why airways collapse on breathing out, and how gas exchange and the right heart suffer.7 steps · 10 questions · 3D disease scene
  3. PH-RS03PneumoniaHow microbes overcome the lung’s defences, why inflammation fills alveoli with exudate, why consolidated lung causes hypoxaemia with a normal or low PaCO2, and how lobar and bronchopneumonia differ.6 steps · 10 questions · 3D disease scene
  4. PH-RS04Pulmonary embolismHow a clot from a deep leg vein lodges in the pulmonary arteries, why it creates dead space and hypoxaemia, how a large embolus strains and can fail the right ventricle, and why lung infarction is uncommon.6 steps · 10 questions · 3D anatomy
  5. PH-RS05PneumothoraxHow a slight negative pressure in the pleural space holds the lung against the chest wall, why air entering that space lets the lung collapse, and how a one-way leak can build pressure that stops blood returning to the heart.6 steps · 10 questions · 3D anatomy
  6. PH-RS06Pleural effusionHow a small amount of pleural fluid is constantly made and drained, why heart failure, low protein, infection and cancer make it accumulate, and how a collection of fluid compresses the lung and changes what you hear and see.5 steps · 10 questions · 3D anatomy
  7. PH-RS07Pulmonary oedemaHow the lungs keep their air spaces dry, why high pressure in the pulmonary capillaries (as in left heart failure) or a damaged, leaky barrier (as in ARDS) floods them with fluid, and how that causes breathlessness, crackles and low oxygen.5 steps · 10 questions · 3D disease scene
  8. PH-RS08Pulmonary fibrosisHow repeated injury to the alveolar lining and abnormal repair replace delicate alveolar walls with scar, why that makes the lungs small and stiff and slows oxygen transfer, and how this causes relentless breathlessness and dry cough.5 steps · 10 questions · 3D disease scene
  9. PH-RS09Benign bronchial tumours and pre-invasive lesionsHow the bronchial and alveolar linings pass through recognisable pre-invasive stages on the way to lung cancer, and how benign tumours such as hamartomas and papillomas grow, block airways or turn up as a nodule on a scan.7 steps · 10 questions · 3D anatomy
  10. PH-RS10Malignant epithelial lung tumoursHow smoke, radon and driver mutations turn airway lining cells into carcinoma, how the main types differ in site and appearance, and how lung cancer obstructs airways, invades the mediastinum, spreads early and causes paraneoplastic syndromes.6 steps · 10 questions · 3D anatomy
  11. PH-RS11Pleural tumoursHow asbestos fibres and lost tumour suppressors such as BAP1 turn mesothelial cells into mesothelioma, how its three types look, how it encases the lung, and how solitary fibrous tumours and metastases differ.6 steps · 10 questions · 3D anatomy
  12. PH-RS12Tumours of the nose, sinuses, pharynx, tonsils and larynxHow the linings of the nose, sinuses, pharynx and larynx give rise to papillomas and carcinomas: EBV in nasopharyngeal carcinoma, HPV and p16 in tonsil cancer, and why glottic cancers cause early hoarseness while supraglottic ones reach nodes early.7 steps · 10 questions · 3D anatomy
  13. PH-RS13Rhinitis, sinusitis, pharyngitis and tonsillitisHow viruses, allergens and bacteria inflame the nose, sinuses and throat: why a blocked ostiomeatal complex turns a cold into sinusitis, how viral, streptococcal and EBV sore throats differ, and why rheumatic fever can follow.7 steps · 10 questions · 3D anatomy
  14. PH-RS14Laryngitis, bronchitis and bronchiolitisHow inflammation narrows the airway at each level: swollen vocal folds in laryngitis, the subglottis in croup and the supraglottis in epiglottitis, the bronchi in acute and chronic bronchitis, and infants’ bronchioles in RSV bronchiolitis.7 steps · 10 questions · 3D anatomy
  15. PH-RS15Bronchiectasis and other changes of the bronchial lumenHow infection, inflammation and failed mucus clearance feed each other until bronchi are permanently widened, why cystic fibrosis and ciliary defects start the cycle, and what narrowing or blocking a bronchus does to the lung beyond.7 steps · 10 questions · 3D anatomy
  16. PH-RS16Pulmonary hypertensionWhy the low-pressure lung circulation can become a high-pressure one, how constricted, remodelled or lost small arteries raise resistance in five groups of causes, and how the right ventricle first thickens and then fails (cor pulmonale).6 steps · 10 questions · 3D anatomy
  17. PH-RS17Atelectasis: collapse of the lungWhy alveoli stay open, how blocked airways, pressure from outside, scarring and lost surfactant make parts of the lung collapse, why collapse lowers oxygen through shunt, and how the X-ray shows which lobe has collapsed.8 steps · 10 questions · 3D anatomy
  18. PH-RS18Acute respiratory distress syndromeHow a direct or indirect injury inflames the alveolar barrier of both lungs, why protein-rich fluid, hyaline membranes and lost surfactant cause shunt and stiff lungs, how the lung heals or scars, and why gentle ventilation and lying prone help.6 steps · 10 questions · 3D disease scene
  19. PH-RS19Neonatal respiratory distress syndromeWhy a premature newborn’s lungs lack surfactant, how collapsing alveoli and hyaline membranes cause shunt and exhausting breathing, how antenatal steroids, surfactant and CPAP act, and why complications reach the lungs, eyes and heart.7 steps · 10 questions · 3D anatomy
  20. PH-RS20Lung abscess and gangreneHow aspirated mouth bacteria, destructive pneumonias, septic emboli and blocked bronchi turn lung into pus, why the cavity shows an air–fluid level, when necrosis becomes gangrene, and how antibiotics, drainage and surgery act.7 steps · 10 questions · 3D anatomy
  21. PH-RS21Fungal and parasitic lung diseaseHow the lung, which filters both the air and all the venous blood, meets fungi and parasites: why the host decides the Aspergillus disease, how Pneumocystis fills the alveoli, and how cysts, migrating larvae and trapped eggs injure the lung.7 steps · 10 questions · 3D anatomy
  22. PH-RS22PneumoconiosesHow inhaled mineral dust is cleared, why carbon is stored harmlessly while silica and asbestos kill macrophages and drive fibrosis, how coal, silica and asbestos scar the lung in different patterns, and why beryllium causes granulomas instead.7 steps · 10 questions · 3D anatomy
  23. PH-RS23Pleuritis, empyema and other pleural collectionsHow an inflamed pleura lays down fibrin, fluid or pus, why the pain is sharp and the rub creaks, how a pleural infection matures into a fibrous peel, what blood and chyle in the chest mean, and how pleural scars and asbestos plaques form.7 steps · 9 questions · 3D anatomy

Renal and urinary

Filtration, the tubules and the urinary tract.

  1. PH-RN01Acute kidney injuryHow too little perfusion, injured tubules or a blocked outflow lower filtration over hours to days, and why creatinine, urea, potassium, acid and fluid then build up in the body.7 steps · 10 questions · 3D anatomy
  2. PH-RN02Chronic kidney diseaseHow losing nephrons makes the survivors overwork and scar, and how failing kidneys cause high blood pressure, acidosis, anaemia and disordered bone and mineral balance.7 steps · 10 questions · 3D anatomy
  3. PH-RN03Nephrotic syndromeHow injury to the podocytes lets large amounts of protein through the glomerular filtration barrier, and why this causes low albumin, oedema, high lipids and a tendency to clot.6 steps · 10 questions · 3D disease scene
  4. PH-RN04Nephritic syndromeHow immune-mediated inflammation of the glomeruli lets red cells into the urine and lowers filtration, causing haematuria with red-cell casts, salt retention, high blood pressure and oedema.6 steps · 10 questions · 3D disease scene
  5. PH-RN05Stones and urinary obstructionHow crystals form stones when urine becomes too concentrated in stone-forming salts, why a stone moving down the ureter causes intense colicky pain, and how blocked urine flow swells the kidney, reduces its function and invites infection.6 steps · 10 questions · 3D disease scene
  6. PH-RN06PyelonephritisHow the urinary tract normally keeps bacteria out, how gut bacteria climb from the urethra to the bladder and up to the kidney, and why kidney infection causes loin pain, high fever and a real risk of sepsis.5 steps · 10 questions · 3D anatomy
  7. PH-RN07Diabetic kidney diseaseHow high blood glucose makes the kidneys over-filter, how years of raised glomerular pressure and glycation thicken and scar the filters so albumin leaks into the urine, and why this is a leading cause of kidney failure worldwide.5 steps · 10 questions · 3D disease scene
  8. PH-RN08Kidney tumoursHow renal cell carcinomas arise from tubule cells, why VHL loss makes clear cell carcinoma act as if starved of oxygen, how it grows into the renal vein and spreads, and where benign tumours and paraneoplastic hormones fit.6 steps · 10 questions · 3D anatomy
  9. PH-RN09Urinary bladder tumoursHow carcinogens in stored urine damage the urothelium, why papillary (FGFR3) and flat (TP53) tumours behave so differently, how depth of invasion sets the stage, and why tumours recur across the whole lining.6 steps · 10 questions · 3D anatomy
  10. PH-RN10Developmental anomalies of the kidney and urinary tractHow the ureteric bud and metanephric blastema build the kidney, and how errors in that meeting, the ascent, the ureteric openings or the urethra, or in ciliary genes, cause agenesis, horseshoe kidney, reflux, valves and polycystic kidneys.8 steps · 10 questions · 3D anatomy
  11. PH-RN11Glomerulonephritis: the main patternsHow the main glomerular diseases differ in which part of the glomerulus they injure and where immune deposits sit, why that decides a nephrotic or nephritic picture, and how three kinds of microscopy tell them apart on a biopsy.7 steps · 10 questions · 3D disease scene
  12. PH-RN12Tubulointerstitial nephritisHow drugs, infections and systemic diseases inflame the tissue between the tubules, why tubular work fails before filtration does, and how oedema and white cells give way to fibrosis and shrunken kidneys when injury persists.7 steps · 10 questions · 3D anatomy
  13. PH-RN13Vascular diseases of the kidneyHow narrowed renal arteries, damaged arterioles, microthrombi and blocked renal arteries or veins injure the kidney: renovascular hypertension, nephrosclerosis, HUS and TTP, infarcts and renal vein thrombosis.7 steps · 10 questions · 3D anatomy
  14. PH-RN14Cystitis: inflammation of the bladderHow the urothelium and regular emptying keep the bladder sterile, how E. coli overcomes them, and how drugs, radiation, viruses, allergy, mycobacteria, faulty macrophages and schistosome eggs each inflame the bladder in their own way.7 steps · 10 questions · 3D anatomy

Digestive and liver

The gut wall, its glands, the liver and the biliary tree, and their tumours.

  1. PH-GI01Gastro-oesophageal refluxHow the barrier at the gastro-oesophageal junction fails, why acid and pepsin injure the squamous lining of the oesophagus, and how healing can leave a stricture or a columnar (Barrett’s) lining.6 steps · 10 questions · 3D anatomy
  2. PH-GI02Peptic ulcer diseaseHow Helicobacter pylori and NSAIDs tip the balance between acid and mucosal defence, what makes an ulcer deeper than an erosion, and why ulcers bleed, perforate or block the gastric outlet.6 steps · 10 questions · 3D disease scene
  3. PH-GI03Coeliac diseaseHow gluten peptides, tissue transglutaminase and HLA-DQ2 or DQ8 switch on a T-cell attack on the small-intestinal lining, flattening the villi and causing malabsorption, anaemia and effects beyond the gut.6 steps · 10 questions · 3D disease scene
  4. PH-GI04Crohn's diseaseHow an immune response to gut bacteria in susceptible people inflames the whole thickness of the bowel wall in patches anywhere from mouth to anus, and why that leads to strictures, fistulae and malabsorption.6 steps · 10 questions · 3D disease scene
  5. PH-GI05Ulcerative colitisHow inflammation confined to the colonic mucosa spreads continuously up from the rectum, why it causes bloody diarrhoea and urgency, and how it differs from Crohn’s disease.6 steps · 10 questions · 3D disease scene
  6. PH-GI06AppendicitisHow blockage of the narrow appendix leads to rising pressure, ischaemia and infection of its wall, why the pain starts around the navel and moves to the right lower abdomen, and why a delay can lead to perforation and peritonitis.6 steps · 10 questions · 3D anatomy
  7. PH-GI07Bowel obstructionHow a blockage stops the gut’s contents moving on, why the bowel above it fills with gas and fluid, how that drains the body’s circulating volume and can cut off the bowel’s own blood supply, and how small and large bowel blockages differ.6 steps · 10 questions · 3D anatomy
  8. PH-GI08Acute pancreatitisHow the pancreas normally keeps its powerful digestive enzymes inactive until they reach the gut, why gallstones and alcohol trigger their activation inside the gland, and how the resulting self-digestion spreads into a body-wide inflammatory illness.6 steps · 10 questions · 3D anatomy
  9. PH-GI09Cirrhosis and portal hypertensionHow years of liver injury turn healthy liver into scar and regenerating nodules, why that raises pressure in the portal vein so blood bypasses the liver through fragile varices, and how loss of liver function causes jaundice, bleeding, ascites and confusion.6 steps · 10 questions · 3D disease scene
  10. PH-GI10Gallstones and biliary obstructionHow bile is made, stored and released, why cholesterol crystallises into stones in some gallbladders, and how a stone blocking the cystic duct or the bile duct causes colic, an inflamed gallbladder, jaundice or a dangerous infection.6 steps · 10 questions · 3D disease scene
  11. PH-GI11Salivary gland tumoursHow the two-layered duct system of the salivary glands gives rise to benign tumours such as pleomorphic adenoma and Warthin tumour and to carcinomas, why a smaller gland means a higher chance of malignancy, and what facial weakness signals.7 steps · 10 questions · 3D anatomy
  12. PH-GI12Oesophageal tumoursHow the squamous lining of the oesophagus gives rise to squamous cell carcinoma and Barrett metaplasia to adenocarcinoma, why these cancers narrow the gullet, invade the mediastinum and reach nodes early, and the benign tumours of its wall.7 steps · 10 questions · 3D anatomy
  13. PH-GI13Precancerous changes of the stomachHow long-standing Helicobacter pylori or autoimmune gastritis wears away the stomach’s glands, how intestinal metaplasia and dysplasia follow (the Correa cascade), which gastric polyps can turn malignant, and what losing acid does.7 steps · 10 questions · 3D anatomy
  14. PH-GI14Gastric tumoursHow the gastric lining gives rise to intestinal-type and diffuse-type adenocarcinoma, why loss of E-cadherin makes linitis plastica, how gastric cancer spreads to nodes, peritoneum and liver, and MALT lymphoma, GIST and neuroendocrine tumours.7 steps · 10 questions · 3D anatomy
  15. PH-GI15Benign tumours of the small and large intestineThe tumours beneath the intestinal lining: lipoma, leiomyoma, haemangioma and lymphangioma, low-risk GIST and neuroendocrine tumours (carcinoids) of the ileum and appendix, how they bleed, obstruct or telescope the bowel, and the carcinoid syndrome.7 steps · 10 questions · 3D anatomy
  16. PH-GI16Malignant tumours of the small and large intestineHow colorectal adenocarcinoma grows from a precursor, invades the bowel wall, spreads to nodes, liver and peritoneum and causes bleeding or obstruction; why small-bowel cancer is rare; and neuroendocrine tumours, GIST and lymphoma.7 steps · 10 questions · 3D anatomy
  17. PH-GI17Gastrointestinal polyps and polyposis syndromesWhat a polyp is and how its tissue decides its future: hyperplastic, serrated, adenomatous, hamartomatous and inflammatory polyps, which can become cancer and why, and the inherited syndromes such as FAP, Lynch and Peutz–Jeghers.7 steps · 10 questions · 3D anatomy
  18. PH-GI18Pancreatic tumoursHow pancreatic ductal adenocarcinoma grows from precursor lesions and invades early, why a tumour of the head causes painless jaundice while one in the body or tail is found late, and the cystic and neuroendocrine tumours of the pancreas.7 steps · 10 questions · 3D anatomy
  19. PH-GI19Peritoneal tumoursHow the peritoneum’s mesothelium and circulating fluid shape its tumours: peritoneal mesothelioma, primary peritoneal serous carcinoma, pseudomyxoma from appendiceal mucinous neoplasms, and carcinomatosis with malignant ascites.6 steps · 10 questions · 3D anatomy
  20. PH-GI20Liver tumoursHow hepatocytes, bile ducts and vessels give rise to liver tumours: haemangioma, focal nodular hyperplasia and adenoma; hepatocellular carcinoma in the injured liver; cholangiocarcinoma; and metastases, the commonest liver malignancy.7 steps · 10 questions · 3D anatomy
  21. PH-GI21Stomatitis and sialadenitisHow the lining of the mouth and the salivary glands become inflamed: aphthous ulcers, herpes and Candida on the mucosa; mumps, bacteria, stones and autoimmunity in the glands; and why too little saliva links the two.7 steps · 10 questions · 3D anatomy
  22. PH-GI22Oesophagitis beyond refluxHow causes other than acid reflux inflame the oesophagus: an allergic type 2 response in eosinophilic oesophagitis, Candida and herpesviruses when immunity is weak, tablets that lodge, swallowed caustics and radiation.7 steps · 10 questions · 3D anatomy
  23. PH-GI23Narrowing, widening and diverticula of the gutHow the gut’s muscular tube can narrow (strictures, achalasia), bulge outwards (pulsion and traction diverticula, colonic diverticular disease) or widen and twist (megacolon, volvulus), and what each change does to the passage of contents.7 steps · 10 questions · 3D anatomy
  24. PH-GI24GastritisHow NSAIDs, alcohol and critical illness erode the stomach lining within hours, how Helicobacter pylori and autoimmunity inflame it for decades in different regions, how chemical gastropathy differs, and how the Sydney system describes it.8 steps · 10 questions · 3D anatomy
  25. PH-GI25Congenital malformations of the gutHow the embryonic gut tube is divided, hollowed out, rotated, given its nerves and opened at its lower end, and how a failure at each step causes oesophageal atresia, duodenal atresia, malrotation, Meckel and Hirschsprung disease or an anorectal malformation.8 steps · 10 questions · 3D anatomy
  26. PH-GI26Chronic pancreatitisHow repeated injury from alcohol, smoking, genes, duct blockage or autoimmunity turns the pancreas into scar and stone, why the pain persists, and why digestion and glucose control fail only once most of the gland is lost.8 steps · 10 questions · 3D anatomy
  27. PH-GI27Peritonitis and foreign material in the peritoneumHow the peritoneum reacts to bacteria, acid, bile, enzymes, blood and foreign material; why infected ascites, a perforated gut and tuberculosis inflame it differently; and how peritonitis spreads to the whole body or is walled off into abscesses and adhesions.8 steps · 10 questions · 3D anatomy
  28. PH-GI28Liver cell injury and necrosisHow toxins, reactive drug metabolites such as paracetamol’s, low oxygen and immune attack injure liver cells; how swelling and fat give way to apoptosis or necrosis; and how the place and extent of necrosis decide recovery or liver failure.7 steps · 9 questions · 3D anatomy
  29. PH-GI29Circulatory disorders of the liverHow blocks at the liver’s inflow, sinusoids and outflow change its circulation: portal vein thrombosis, the rare liver infarct, sinusoidal obstruction syndrome, Budd–Chiari syndrome and cardiac cirrhosis, and the shock liver of low blood flow.7 steps · 10 questions · 3D anatomy
  30. PH-GI30HepatitisHow the hepatitis viruses A to E differ in spread and persistence, why the immune attack rather than the virus kills liver cells, how acute and chronic hepatitis look and are graded and staged, and how autoimmune and drug causes compare.7 steps · 9 questions · 3D anatomy
  31. PH-GI31Liver abscessHow bacteria reach the liver through the bile ducts, portal vein, hepatic artery or neighbouring tissue to form a pyogenic abscess, how Entamoeba dissolves liver into “anchovy paste”, and how a hydatid cyst differs from both.7 steps · 9 questions · 3D anatomy
  32. PH-GI32Alcohol-related liver diseaseHow the liver breaks down alcohol, why excess NADH, acetaldehyde and oxidative stress fill hepatocytes with fat and injure them, and how fatty liver can progress to alcoholic hepatitis and micronodular cirrhosis.6 steps · 9 questions · 3D disease scene
  33. PH-GI33CholestasisHow hepatocytes make bile by pumping bile acids into the canaliculi, why drugs, sepsis, pregnancy, autoimmune duct disease or a blocked duct stop the flow, and how retained bile causes itch, jaundice and fat-soluble vitamin deficiency.6 steps · 10 questions · 3D anatomy

Endocrine and metabolic

Insulin and glucose, the thyroid, pituitary and adrenal glands, and their tumours.

  1. PH-EN01Type 1 diabetesHow autoimmune destruction of the pancreatic beta cells removes insulin, why glucose then stays in the blood and spills into the urine, and why fat and muscle are broken down, which can lead to ketoacidosis.6 steps · 10 questions · 3D anatomy
  2. PH-EN02Type 2 diabetesHow insulin resistance in liver, muscle and fat and a gradual failure of the beta cells combine to raise blood glucose, often silently, and how years of hyperglycaemia damage small and large blood vessels.6 steps · 10 questions · 3D anatomy
  3. PH-EN03Diabetic ketoacidosisHow insulin deficiency and stress hormones release fatty acids that the liver turns into ketoacids, causing a raised anion gap metabolic acidosis, severe dehydration and dangerous shifts in potassium.7 steps · 10 questions · 3D anatomy
  4. PH-EN04HyperthyroidismHow excess thyroid hormone, from TSH-receptor antibodies in Graves’ disease, autonomous nodules or a damaged, leaking gland, speeds metabolism and amplifies adrenergic effects, and why the cause changes the findings.7 steps · 10 questions · 3D anatomy
  5. PH-EN05HypothyroidismHow the thyroid makes hormones that set the pace of metabolism, why autoimmune destruction or iodine deficiency leaves too little hormone, and how a slowed metabolism explains tiredness, cold intolerance, weight gain and the rest of the picture.6 steps · 10 questions · 3D anatomy
  6. PH-EN06Cushing’s syndromeHow cortisol normally helps the body handle stress, why long-term steroid medicines or tumours of the pituitary or adrenal glands produce too much, and how excess cortisol reshapes fat, muscle, skin, bone, blood sugar and blood pressure.6 steps · 10 questions · 3D anatomy
  7. PH-EN07Adrenal insufficiencyHow the adrenal cortex makes cortisol and aldosterone, why autoimmune damage, pituitary disease or stopping steroids leaves too little, and how the loss causes tiredness, low blood pressure, salt craving, darker skin and adrenal crisis.6 steps · 10 questions · 3D anatomy
  8. PH-EN08Adrenal gland tumoursWhich adrenal cells give rise to which tumours: common, usually silent cortical adenomas, adenomas that secrete aldosterone or cortisol, rare invasive adrenocortical carcinoma, and catecholamine-secreting phaeochromocytoma.7 steps · 10 questions · 3D anatomy
  9. PH-EN09Pituitary and hypothalamic tumoursHow tumours of the anterior pituitary cause disease by hormone excess (prolactin, growth hormone, ACTH) or by pressing on the optic chiasm and the normal gland, and how craniopharyngioma and other masses above the sella damage the hypothalamus.6 steps · 10 questions · 3D anatomy
  10. PH-EN10Thyroid tumoursHow the thyroid’s two cell lines give rise to its tumours: common benign nodules and follicular adenomas, papillary and follicular carcinoma, medullary carcinoma from C cells, and rare, rapidly invasive anaplastic carcinoma.7 steps · 10 questions · 3D anatomy
  11. PH-EN11Parathyroid hyperplasia and tumoursHow parathyroid chief cells set blood calcium, why a single adenoma is the usual cause of primary hyperparathyroidism, how hyperplasia arises in MEN1 and kidney disease, and how high calcium affects bones, kidneys, gut and brain.7 steps · 10 questions · 3D anatomy
  12. PH-EN12ThyroiditisHow autoimmunity, viruses, bacteria and fibrosis injure the thyroid follicles, why fast destruction leaks stored hormone (thyrotoxicosis with a low iodine uptake, then hypothyroidism), and how each form looks.7 steps · 10 questions · 3D anatomy
  13. PH-EN13GoitreHow a shortage of thyroid hormone, most often from too little iodine, raises TSH and enlarges the thyroid, how a diffuse goitre becomes multinodular, why some nodules start making hormone on their own, and what a large goitre compresses.6 steps · 10 questions · 3D anatomy
  14. PH-EN14Congenital adrenal hyperplasia and adrenal hormone disorders comparedHow an inherited block in cortisol synthesis, most often 21-hydroxylase deficiency, lets ACTH enlarge both adrenals and divert precursors into androgens, causing virilisation and salt-wasting, and how every adrenal syndrome compares.7 steps · 10 questions · 3D anatomy

Neurological

Blood supply of the brain, myelin, neurotransmission and pressure in the skull.

  1. PH-NE01Ischaemic strokeHow a blocked cerebral artery starves the brain of oxygen, why tissue dies in a core but can survive for a time in the penumbra, and why the deficit depends on which artery is blocked.7 steps · 10 questions · 3D disease scene
  2. PH-NE02Haemorrhagic strokeHow rupture of a small deep artery bleeds into the brain, how a ruptured aneurysm bleeds around it, and why blood in a closed skull raises pressure and injures the brain.6 steps · 10 questions · 3D disease scene
  3. PH-NE03Multiple sclerosisHow an immune attack on central myelin slows or blocks nerve conduction, why plaques favour the optic nerves, periventricular white matter and spinal cord, and why the disease can relapse or progress.7 steps · 10 questions · 3D anatomy
  4. PH-NE04Parkinson's diseaseHow loss of dopamine-producing neurones in the substantia nigra disturbs the basal ganglia circuit that releases movement, causing slowness, stiffness and tremor, and why other symptoms often come first.6 steps · 10 questions · 3D anatomy
  5. PH-NE05Alzheimer's diseaseHow amyloid plaques and tau tangles build up over many years, why synapses and neurones are lost first in the memory circuits of the medial temporal lobe, and how this produces progressive memory loss and wider decline.6 steps · 10 questions · 3D anatomy
  6. PH-NE06Epilepsy and seizuresHow the balance between excitation and inhibition normally keeps cortical activity orderly, why a group of neurones can fire together abnormally, and how the site and spread of that discharge decide what a seizure looks like.6 steps · 10 questions · 3D anatomy
  7. PH-NE07Raised intracranial pressureHow a fixed skull holds brain, blood and cerebrospinal fluid in balance, why masses, swelling or blocked CSF raise the pressure once compensation runs out, and how falling blood flow and herniation of brain tissue become life-threatening.6 steps · 10 questions · 3D anatomy
  8. PH-NE08Tumours of the brain and spinal cordHow glial and other cells of the brain and spinal cord give rise to tumours, how the WHO classification combines microscopy with molecular markers, and why a tumour’s site, oedema and mass effect decide what it does.7 steps · 10 questions · 3D anatomy
  9. PH-NE09Meningeal and peripheral nerve tumoursHow arachnoid and Schwann cells give rise to meningiomas, schwannomas and neurofibromas, why these mostly benign tumours harm by compressing brain, cord and nerves, and how NF1 and NF2 predispose to them and to malignant nerve sheath tumours.7 steps · 10 questions · 3D anatomy
  10. PH-NE10Cerebral oedemaWhy the brain swells in four ways (a leaking barrier, failing cell pumps, CSF pushed into the ventricle wall, plasma more dilute than brain), how each looks to the eye, the microscope and the scanner, and why the type decides which treatment works.7 steps · 10 questions · 3D anatomy
  11. PH-NE11HydrocephalusHow CSF is made, flows and is absorbed; why a block in the ventricles or failed absorption makes them swell; how hydrocephalus differs in infants, adults and older people with normal pressure; what only looks like it; and how shunts and ventriculostomy work.7 steps · 10 questions · 3D anatomy
  12. PH-NE12Extradural, subdural and subarachnoid haemorrhageHow bleeding outside the brain differs by compartment: arterial extradural clots with a lucid interval, venous subdural crescents that grow over weeks, blood in the CSF after aneurysm rupture, germinal matrix bleeds in preterm babies, and how blood ages.7 steps · 10 questions · 3D anatomy
  13. PH-NE13Meningitis and other meningeal infectionsHow bacteria, viruses, mycobacteria and fungi reach the CSF, why bacterial meningitis fills it with pus and injures the brain, how tuberculous and cryptococcal infection smoulder at the base, and how CSF findings and meningococcal sepsis follow.7 steps · 10 questions · 3D anatomy
  14. PH-NE14Other demyelinating diseasesHow antibodies to astrocyte water channels (NMOSD) or to myelin (MOGAD, ADEM), a virus that kills oligodendrocytes (PML), an osmotic shock and inherited enzyme defects strip central myelin, and how each is told apart from MS.8 steps · 10 questions · 3D anatomy
  15. PH-NE15Other neurodegenerative diseasesHow misfolded tau, TDP-43, alpha-synuclein, huntingtin and prion protein spread through particular networks, causing frontotemporal dementia, Lewy body dementia, PSP, MSA, Huntington disease, motor neurone disease and CJD.8 steps · 10 questions · 3D anatomy
  16. PH-NE16Peripheral nerve diseaseHow peripheral nerves fail by losing axons or myelin: why metabolic neuropathies start in the feet, how immune attack strips myelin in Guillain–Barré syndrome, how pressure harms the median nerve, and how nerve conduction tells them apart.8 steps · 10 questions · 3D anatomy

Blood and coagulation

Red cells and haemoglobin, clotting and the bone marrow.

  1. PH-HE01Iron-deficiency anaemiaHow the body absorbs, recycles and stores iron, why stores empty before haemoglobin falls, why iron deficiency makes small, pale red cells, and how the symptoms and the search for a cause follow from the mechanism.6 steps · 10 questions · 3D disease scene
  2. PH-HE02B12 and folate deficiency: megaloblastic anaemiaHow vitamin B12 and folate let dividing cells copy their DNA, why their lack makes large, immature blood cells, why B12 deficiency also damages nerves, and how the cause is traced to the stomach, the ileum or the diet.6 steps · 10 questions · 3D disease scene
  3. PH-HE03Sickle cell diseaseHow a single change in the beta-globin gene makes haemoglobin polymerise when it gives up oxygen, how stiff sickled cells block small vessels and break down early, and how this explains pain crises, organ damage and infection risk.6 steps · 10 questions · 3D disease scene
  4. PH-HE04ThalassaemiaHow an imbalance between alpha and beta globin chains damages developing red cells, why the marrow expands and the spleen enlarges, why iron accumulates, and how the inherited forms range from silent trait to transfusion dependence.6 steps · 10 questions · 3D disease scene
  5. PH-HE05HaemophiliaHow factors VIII and IX amplify thrombin to build a stable clot, why their lack lets a platelet plug form but fail, why bleeding goes into joints and muscles, and how the X-linked inheritance shapes who is affected.6 steps · 10 questions · 3D anatomy
  6. PH-HE06LeukaemiaHow a single blood-forming cell escapes normal control, why leukaemic cells crowd out normal production to cause anaemia, infection and bleeding, and how acute and chronic, myeloid and lymphoid leukaemias differ.6 steps · 10 questions · 3D disease scene
  7. PH-HE07Thymic hyperplasia and tumoursHow the thymus educates T cells, why it shows follicular hyperplasia in myasthenia and rebound hyperplasia after stress, and how thymomas and thymic carcinoma arise from its epithelial cells, invade the mediastinum and cause autoimmunity.7 steps · 10 questions · 3D anatomy
  8. PH-HE08Non-Hodgkin lymphomasHow each non-Hodgkin lymphoma mirrors a stage of normal B-cell or T-cell development in the lymph node, how translocations such as t(14;18), t(11;14) and MYC drive them, and why some grow over years and others over weeks.7 steps · 10 questions · 3D anatomy
  9. PH-HE09Hodgkin lymphomaHow rare Hodgkin Reed–Sternberg cells, crippled B cells that escaped death, build a tumour made mostly of reactive cells, why their cytokines cause fever, sweats and weight loss, and how the disease spreads node by node.6 steps · 10 questions · 3D anatomy
  10. PH-HE10Bone marrow pathologyHow the marrow fails or turns clonal: stem-cell loss in aplastic anaemia, overproduction in myeloproliferative neoplasms, ineffective production in myelodysplasia, plasma cell myeloma and its CRAB effects, and infiltration and fibrosis.7 steps · 10 questions · 3D anatomy
  11. PH-HE11Diseases of the spleenHow the spleen filters blood and fights blood-borne bacteria, why congestion, infection, blood diseases and storage enlarge it, how a big spleen destroys blood cells, and what infarction, rupture and loss of the spleen do.7 steps · 9 questions · 3D anatomy

Infection and immune disease

Hypersensitivity and allergy, infection by bacteria, viruses, fungi and parasites, autoimmunity, connective tissue disease and graft rejection.

  1. PH-IM01AnaphylaxisHow IgE primes mast cells, why re-exposure to an allergen releases histamine and other mediators throughout the body, and how leaky vessels and swollen airways cause shock and obstruction within minutes.7 steps · 10 questions · 3D anatomy
  2. PH-IM02SepsisHow an infection at one site can set off a dysregulated response throughout the body, why leaky, dilated vessels and patchy microcirculation starve cells of oxygen, and how this causes organ dysfunction and septic shock.7 steps · 10 questions · 3D anatomy
  3. PH-IM03HIV infectionHow HIV enters CD4 helper T cells, copies its RNA into DNA and hides in their chromosomes, why CD4 cells decline over years, and why their loss lets opportunistic infections and cancers take hold.7 steps · 10 questions
  4. PH-IM04TuberculosisHow the immune system normally clears inhaled microbes, why Mycobacterium tuberculosis survives inside macrophages, how granulomas contain it as latent infection, and how reactivation destroys lung tissue and spreads.6 steps · 10 questions · 3D anatomy
  5. PH-IM05Systemic lupus erythematosusHow the immune system normally ignores the contents of the body’s own cells, why in lupus it makes antibodies against nuclear material, and how immune complexes and complement inflame the skin, joints, kidneys, blood and serous linings.6 steps · 10 questions · 3D disease scene
  6. PH-IM06Myasthenia gravisHow a nerve signal normally crosses the neuromuscular junction with a margin to spare, why antibodies against acetylcholine receptors erode that margin, and how this causes weakness that worsens with use, often starting in the eyelids and eye muscles.7 steps · 10 questions · 3D anatomy
  7. PH-IM07SyphilisHow Treponema pallidum slips through skin or mucosa and spreads early, why plasma cells and obliterative endarteritis mark every stage, and how untreated infection can damage the aorta and nervous system years later.7 steps · 10 questions · 3D anatomy
  8. PH-IM08How viruses injure tissueHow a virus takes over a cell, why some viruses kill cells directly while others injure tissue mainly through the immune response, how some hide for life, and how a few push cells towards cancer.7 steps · 10 questions · 3D anatomy
  9. PH-IM09Fungal infectionHow barriers and phagocytes keep fungi in check, why most fungal disease follows a failure of one of them, how moulds invade blood vessels, and how the same fungus can cause allergy, a fungus ball or invasive disease.6 steps · 10 questions · 3D anatomy
  10. PH-IM10Parasitic infectionHow protozoa and worms live at the host’s expense: how malaria parasites destroy red cells and block small vessels, how gut parasites damage the mucosa, and why worms provoke eosinophils, IgE and, around trapped eggs, fibrosis.7 steps · 10 questions · 3D anatomy
  11. PH-IM11Hypersensitivity reactionsHow the immune system harms the body it protects: IgE and mast cells (type I), antibodies against cells and tissue (type II), deposited immune complexes (type III) and sensitised T cells (type IV), with their timing and typical diseases.6 steps · 10 questions · 3D anatomy
  12. PH-IM12Tolerance and autoimmunityHow the immune system learns to leave the body alone, through central and peripheral tolerance, how genes and triggers break that tolerance, and how the resulting autoimmune response injures one organ or many.6 steps · 10 questions · 3D anatomy
  13. PH-IM13Systemic sclerosisHow injury to small vessels, autoimmunity and overactive fibroblasts combine to thicken the skin and scar the oesophagus, lungs, heart and kidneys in systemic sclerosis, and why Raynaud’s phenomenon usually comes first.7 steps · 10 questions · 3D anatomy
  14. PH-IM14Polymyositis, dermatomyositis and Sjögren syndromeHow autoimmune attack on muscle causes symmetrical proximal weakness in polymyositis and dermatomyositis, and how lymphocytes invading the salivary and tear glands cause the dry mouth and eyes of Sjögren syndrome.7 steps · 10 questions · 3D anatomy
  15. PH-IM15Graft rejectionWhy the immune system attacks a transplanted organ: how T cells and antibodies recognise donor HLA, how hyperacute, acute and chronic rejection damage the graft, and how donor cells can attack the recipient instead.6 steps · 10 questions · 3D anatomy
  16. PH-IM16Lymphadenitis: reactive and infected lymph nodesHow a node filtering infected lymph swells, why bacteria in the node make it tender and can form an abscess, which reactive and granulomatous patterns point to the cause, and how a reactive node is told apart from lymphoma.7 steps · 9 questions · 3D anatomy

Musculoskeletal

Joints, bone strength and repair, crystals and the spine.

  1. PH-MS01OsteoarthritisHow the cartilage, bone and lining of a synovial joint remodel together when repair cannot keep pace with damage, and why that causes use-related pain, stiffness, crepitus and bony swelling.6 steps · 10 questions · 3D disease scene
  2. PH-MS02Rheumatoid arthritisHow an autoimmune response turns the thin lining of synovial joints into an invasive, inflamed tissue that erodes cartilage and bone, why it affects small joints symmetrically, and why it is a disease of the whole body.6 steps · 10 questions · 3D disease scene
  3. PH-MS03OsteoporosisHow continuous bone remodelling tips towards resorption after the menopause and with age, how that thins and disconnects the trabecular lattice, and why the result is silent until a bone breaks from a minor fall.6 steps · 10 questions · 3D disease scene
  4. PH-MS04GoutHow a raised uric acid level leads to urate crystals in cool, peripheral joints, why those crystals set off one of the most intense inflammatory responses in medicine, and how repeated attacks lead to tophi and joint damage.6 steps · 10 questions · 3D disease scene
  5. PH-MS05Disc prolapse and radiculopathyHow an ageing intervertebral disc tears and lets its nucleus escape, how that compresses and inflames a nerve root, and how the pattern of pain, numbness and weakness reveals which root is affected and when it is an emergency.6 steps · 10 questions · 3D anatomy
  6. PH-MS06Fracture healingHow a broken bone heals through a haematoma, inflammation, a soft cartilage callus and a hard bony callus that is remodelled into normal bone, and why movement, poor blood supply, infection and smoking can make healing fail.6 steps · 10 questions · 3D anatomy
  7. PH-MS07Benign bone, cartilage and joint tumoursHow age and site within a bone predict which benign tumour is present, how bone-forming, cartilage-forming and giant-cell-rich tumours and bone cysts arise and weaken bone, and why some recur or, rarely, turn malignant.7 steps · 10 questions · 3D anatomy
  8. PH-MS08Malignant bone, cartilage and joint tumoursWhy metastases are the commonest malignant tumours in bone, how osteosarcoma, chondrosarcoma and Ewing sarcoma differ in age, site, genes and appearance, how they destroy bone and lift periosteum, and what lytic and sclerotic lesions cause.7 steps · 10 questions · 3D anatomy
  9. PH-MS09Osteomyelitis and septic arthritisHow pyogenic bacteria reach bone and joints, why childhood bone infection starts in the metaphysis, how trapped pus kills bone to leave a sequestrum and chronic infection, and how enzymes destroy a septic joint within days.8 steps · 10 questions · 3D anatomy
  10. PH-MS10Tuberculosis and other specific infections of bone and jointHow granulomatous (“specific”) infections destroy bone slowly: tuberculosis of the spine with gibbus, cold and psoas abscesses, tuberculous joints, skeletal syphilis from sabre tibia to gumma, and brucellar and fungal bone infection.8 steps · 10 questions · 3D anatomy
  11. PH-MS11Osteomalacia, rickets and other metabolic bone diseaseWhy bone matrix fails to mineralise when vitamin D, calcium or phosphate runs short, how that softens adult bone (osteomalacia) and disorganises the growth plate (rickets), how kidney disease remodels bone, and why scurvy is a matrix defect.7 steps · 10 questions · 3D anatomy
  12. PH-MS12Paget disease of boneHow overactive giant osteoclasts set off fast, chaotic remodelling in a few bones, why the result is a mosaic of enlarged but weaker bone, and how that causes bowing, fractures, deafness, nerve compression, high-output failure and, rarely, osteosarcoma.6 steps · 10 questions · 3D anatomy
  13. PH-MS13Primary muscle diseasesHow faults in the muscle fibre itself cause weakness: a missing dystrophin anchor in Duchenne dystrophy, a toxic RNA repeat in myotonic dystrophy, failing fuel in metabolic myopathies, and drugs or injury that break fibres down.8 steps · 10 questions · 3D anatomy

Reproductive and obstetric

The uterus, ovaries and tubes, the testes, penis and prostate, the placenta, and their tumours.

  1. PH-RO01EndometriosisHow tissue like the lining of the uterus grows outside it, bleeds and inflames with each cycle, and leaves scarring and adhesions that cause pelvic pain and can reduce fertility.7 steps · 10 questions · 3D anatomy
  2. PH-RO02Polycystic ovary syndromeHow androgen excess, an altered LH and FSH balance and insulin resistance stop follicles maturing, why that disrupts ovulation and periods, and why the condition looks different in different people.7 steps · 10 questions · 3D anatomy
  3. PH-RO03Ectopic pregnancyHow damage to the uterine tube delays the embryo so that it implants outside the uterine cavity, why the tube cannot contain the pregnancy, and how rupture causes internal bleeding.6 steps · 10 questions · 3D anatomy
  4. PH-RO04Uterine fibroidsHow a single smooth muscle cell of the uterine wall grows, under oestrogen and progesterone, into a benign tumour, and why its position decides whether it causes heavy periods or pressure symptoms.7 steps · 10 questions · 3D anatomy
  5. PH-RO05Benign prostatic enlargementHow the prostate surrounds the urethra below the bladder, why hormone-driven growth with age narrows that channel, and how the bladder’s response produces weak flow, frequency, urgency, night-time passing of urine and retention.6 steps · 10 questions · 3D anatomy
  6. PH-RO06Pre-eclampsiaHow the placenta normally remodels the mother’s spiral arteries into wide, low-resistance channels, why failed remodelling leaves it starved of blood, and how factors from the stressed placenta damage the mother’s blood vessels, kidneys, liver and brain.6 steps · 10 questions · 3D anatomy
  7. PH-RO07Prostate tumoursHow prostate adenocarcinoma arises from the luminal cells of the peripheral zone, why losing the basal cell layer marks invasion, how Gleason patterns grade it, and how spread to nodes and bone causes its effects.6 steps · 10 questions · 3D anatomy
  8. PH-RO08Testicular tumoursHow most testicular cancers arise from germ cells that failed to mature before birth, how seminoma and non-seminomatous tumours differ in appearance and markers, and why they spread first to the para-aortic nodes.6 steps · 10 questions · 3D anatomy
  9. PH-RO09Inflammation and benign lesions of the penisHow the warm, moist space under the foreskin favours inflammation, how repeated inflammation and lichen sclerosus scar it into phimosis, how low-risk HPV makes warts, and how a fibrous plaque bends the penis in Peyronie disease.6 steps · 10 questions · 3D anatomy
  10. PH-RO10Penile tumoursHow penile squamous cell carcinoma arises by two routes, high-risk HPV or chronic inflammation under a tight foreskin, through intraepithelial neoplasia to invasion of the erectile bodies and a predictable spread to the groin nodes.7 steps · 10 questions · 3D anatomy
  11. PH-RO11Precancerous lesions and carcinoma of the vulvaHow vulval squamous cell carcinoma arises by two routes, high-risk HPV through vulval HSIL or lichen sclerosus through differentiated VIN, and spreads stepwise to the groin nodes.7 steps · 10 questions · 3D anatomy
  12. PH-RO12Endometrial hyperplasia and adenomyosisHow unopposed oestrogen causes endometrial hyperplasia, how a PTEN-deficient clone forms atypical hyperplasia (the precursor of endometrioid carcinoma), and how endometrium within the uterine muscle (adenomyosis) causes heavy, painful periods.7 steps · 10 questions · 3D anatomy
  13. PH-RO13Tumours of the cervixHow persistent high-risk HPV transforms the metaplastic cells of the cervical transformation zone, through low- and high-grade intraepithelial lesions, into squamous carcinoma or adenocarcinoma that spreads into the parametria, ureters and pelvic nodes.7 steps · 10 questions · 3D anatomy
  14. PH-RO14Benign and malignant tumours of the uterine bodyWhich cells of the uterine body give rise to which tumours, how unopposed oestrogen or an early TP53 mutation leads to endometrial carcinoma, how it invades and spreads, and why bleeding is so often its first sign.5 steps · 8 questions · 3D anatomy
  15. PH-RO15Gestational trophoblastic diseaseHow an abnormal fertilisation with too much paternal genetic material makes the trophoblast overgrow into a molar pregnancy, why very high hCG causes its features, and how trophoblastic tissue can persist, invade and spread.5 steps · 8 questions · 3D anatomy
  16. PH-RO16Ovarian cysts and benign ovarian tumoursHow a follicle or corpus luteum becomes a functional cyst, how the ovary’s epithelial, germ and stromal cells give rise to benign tumours such as cystadenomas and dermoid cysts, and why a cyst can bleed, burst or twist.5 steps · 8 questions · 3D anatomy
  17. PH-RO17Malignant ovarian tumoursHow most ovarian carcinomas begin in tubal or endometriotic epithelium, how the five main carcinoma types differ, how germ cell and stromal tumours behave, and why spread across the peritoneum makes ovarian cancer silent until late.5 steps · 9 questions · 3D anatomy
  18. PH-RO18Hyperplastic and benign breast changesHow the terminal duct lobular unit responds to cyclical hormones, why cysts, hyperplasia with and without atypia, fibroadenoma and phyllodes tumour form, and what each means for later breast cancer risk.5 steps · 8 questions · 3D anatomy
  19. PH-RO19Breast tumoursHow breast carcinoma arises from luminal cells of the lobule, why DCIS and lobular neoplasia precede ductal and lobular invasion, what oestrogen receptor, PR and HER2 status say about its biology, and how it spreads.5 steps · 9 questions · 3D anatomy
  20. PH-RO20ProstatitisHow bacteria reach the prostate and cause acute and chronic bacterial prostatitis, why most prostatitis is pelvic pain without infection, how granulomas form after BCG and other causes, and why an inflamed gland raises PSA.7 steps · 10 questions · 3D anatomy
  21. PH-RO21Epididymitis and orchitisHow bacteria travel backwards down the ductus deferens to inflame the epididymis, how mumps damages the seminiferous tubules inside a rigid capsule, how tuberculosis and syphilis form granulomas, and how to tell infection from a twisted testis.8 steps · 10 questions · 3D anatomy
  22. PH-RO22Endometritis and other uterine inflammationHow bacteria reach the endometrium after birth, miscarriage or procedures, why retained tissue feeds infection and sepsis, why plasma cells define chronic endometritis, how pus collects behind a narrowed cervix, and how scarring causes Asherman syndrome.8 steps · 10 questions · 3D anatomy
  23. PH-RO23Cervicitis, ectropion and pseudoerosionHow the two linings of the cervix meet and move, why hormones bring columnar lining out as an ectropion (the old "erosion", really a pseudoerosion), how Nabothian cysts and polyps form, and how sexually transmitted organisms inflame the cervix.7 steps · 10 questions · 3D anatomy
  24. PH-RO24Salpingitis, oophoritis and pelvic inflammatory diseaseHow bacteria climb from the cervix to inflame the endometrium, uterine tubes, ovaries and peritoneum, how pus collects and reaches the liver capsule, how tuberculosis and actinomycosis differ, and why the scars cause infertility and ectopic pregnancy.8 steps · 10 questions · 3D anatomy
  25. PH-RO25Mastitis and breast abscessHow milk stasis inflames the breastfeeding breast and Staphylococcus aureus turns it into infection or abscess, how smoking and squamous metaplasia cause periductal mastitis, and how duct ectasia, granulomatous mastitis and fat necrosis mimic cancer.8 steps · 10 questions · 3D anatomy

Eye and ear

Pressure and clarity in the eye, the retina and the middle ear.

  1. PH-SE01GlaucomaHow aqueous humour is made and drained, why impaired drainage raises eye pressure, how the optic nerve head is damaged and why vision is lost silently from the periphery, and how acute angle closure differs.6 steps · 10 questions · 3D anatomy
  2. PH-SE02CataractHow the lens stays transparent through the precise packing of its proteins, how age, light, glucose and steroids make those proteins clump and scatter light, and why that blurs and dims vision and causes glare.5 steps · 10 questions · 3D anatomy
  3. PH-SE03Diabetic retinopathyHow years of high blood glucose damage the retina’s small vessels, making them leak and close, why an oxygen-starved retina grows fragile new vessels, and how this causes swelling of the macula, bleeding and detachment.6 steps · 10 questions · 3D anatomy
  4. PH-SE04Otitis mediaHow the auditory tube keeps the middle ear ventilated, why it fails during colds (especially in young children), how trapped fluid becomes infected and painful, and why lingering fluid muffles hearing.6 steps · 10 questions · 3D anatomy

Skin, dental disease and cancer

The skin barrier, burns and healing, the teeth and their supports, and how tumours are named, grow and spread.

  1. PH-SD01EczemaHow a leaky skin barrier and an allergic type of inflammation feed each other, why the skin becomes dry, itchy and inflamed, how scratching keeps the cycle going and why eczema often comes with asthma and hay fever.6 steps · 10 questions · 3D disease scene
  2. PH-SD02PsoriasisHow an immune loop centred on interleukin-23 and interleukin-17 makes keratinocytes multiply about ten times faster than normal, producing thick, red, scaly plaques, and why psoriasis can involve nails, joints and the whole body.6 steps · 10 questions · 3D disease scene
  3. PH-SD03Burns and wound healingHow the depth of a burn decides which parts of the skin survive, why large burns leak fluid into the tissues and cause shock, and how wounds heal through inflammation, new tissue and remodelling, sometimes with thick scars and contractures.6 steps · 10 questions · 3D disease scene
  4. PH-SD04Dental cariesHow bacteria in dental plaque turn dietary sugar into acid, how repeated acid attacks dissolve enamel faster than saliva and fluoride can repair it, and how decay spreads through dentine to inflame the pulp and cause abscesses.6 steps · 10 questions · 3D disease scene
  5. PH-SD05PeriodontitisHow plaque at the gum line inflames the gums, why in some people the immune response goes on to destroy the ligament and bone that hold the teeth, and why that silent process ends in pockets, loose teeth and tooth loss.6 steps · 10 questions · 3D disease scene
  6. PH-SD06Neoplasia, invasion and metastasisHow accumulated mutations release a cell from normal growth controls, how an epithelium passes through dysplasia and carcinoma in situ to invasion through its basement membrane, how cancer spreads, and how tumours affect the whole body.7 steps · 10 questions · 3D disease scene
  7. PH-SD07Naming and classifying tumoursHow tumours are named and classified: by the normal cell they copy and by how they behave, the rules for benign tumours, carcinomas and sarcomas, the names that break the rules, and how the WHO classification sorts tumours today.5 steps · 8 questions · 3D anatomy
  8. PH-SD08Tumour histology and regressive changesWhat tumours look like under the microscope: architecture, differentiation and atypia, what a grade measures, and the regressive changes (necrosis, haemorrhage, cysts, hyalinisation, calcification) that follow when a tumour outgrows its supply.5 steps · 8 questions · 3D anatomy
  9. PH-SD09Invasion, recurrence and cancer cachexiaHow cancer cells detach, digest and migrate through tissue, the routes they take and why some tumours spread more than others, why cancer can recur after removal, and how cancer cachexia wastes muscle in ways that feeding cannot fully reverse.5 steps · 9 questions · 3D anatomy
  10. PH-SD10Benign epithelial tumoursHow benign tumours of surface epithelium (papillomas) and of glands (adenomas) arise, why an intact basement membrane keeps them confined, how they still obstruct, bleed or secrete, and why some adenomas can progress to carcinoma.5 steps · 9 questions · 3D anatomy
  11. PH-SD11Carcinomas: malignant epithelial tumoursHow carcinomas are typed by what their cells imitate (squamous cell, adenocarcinoma, urothelial, undifferentiated), how keratin pearls and glands are read, why they spread first by lymphatics, and how cytokeratins prove epithelial origin.5 steps · 9 questions · 3D anatomy
  12. PH-SD12Benign mesenchymal tumoursHow benign tumours of fat, fibrous tissue, muscle, cartilage, bone and vessels are named by the tissue they copy, why most grow slowly inside a capsule, how they still cause harm by site, and where intermediate tumours such as desmoids fit.5 steps · 9 questions · 3D anatomy
  13. PH-SD13Sarcomas: malignant mesenchymal tumoursHow malignant tumours of fat, fibrous tissue, muscle, vessels and nerve sheaths arise, why they are named by the tissue they imitate, how they grow within compartments and spread through the blood to the lungs, and what their grade measures.4 steps · 9 questions · 3D anatomy
  14. PH-SD14Tumour growth: kinetics, angiogenesis and heterogeneityWhy a tumour grows: cell production outpacing cell loss, the long silent period before it can be felt, the vessels it must recruit beyond a millimetre or two, and the competing clones that make every tumour a mosaic.4 steps · 9 questions · 3D anatomy
  15. PH-SD15Prognostic and predictive factorsWhat a cancer’s grade, stage, report features and molecular markers say about its likely course (prognostic factors) and about which treatments could work (predictive factors), why they differ, and their limits.4 steps · 8 questions · 3D anatomy
  16. PH-SD16Tumours of the oral cavityHow tobacco, areca nut and alcohol drive the oral lining through white and red patches and dysplasia to squamous cell carcinoma, how it invades and reaches the neck nodes, and the odontogenic tumours of the jaws such as ameloblastoma.5 steps · 9 questions · 3D anatomy
  17. PH-SD17Non-melanocytic skin tumoursHow ultraviolet light mutates keratinocytes, how benign seborrhoeic keratosis differs from the dysplasia of actinic keratosis and Bowen disease, and why squamous cell carcinoma can spread to nodes while basal cell carcinoma destroys locally.5 steps · 9 questions · 3D anatomy
  18. PH-SD18Melanocytic skin tumoursHow melanocytes form benign naevi that stop growing, how melanoma escapes those brakes, how its radial and vertical growth phases and clinical subtypes differ, and why Breslow thickness and ulceration are what its staging measures.5 steps · 9 questions · 3D anatomy
  19. PH-SD19Benign tumours of childhoodWhy most lumps in children are benign and developmental: hamartoma, choristoma and true neoplasm; infantile haemangioma, which grows then involutes; vascular and lymphatic malformations; mature teratoma; congenital naevi and fibrous tumours.5 steps · 8 questions · 3D anatomy
  20. PH-SD20Malignant tumours of childhoodWhy childhood cancers differ from adult ones (embryonal origin, few mutations, inherited RB1, WT1 and TP53 faults) and how leukaemia, brain tumours, neuroblastoma, Wilms tumour, retinoblastoma and other childhood tumours arise and spread.5 steps · 8 questions · 3D anatomy
  21. PH-SD21Other inflammatory skin diseasesHow a pathologist reads a rash by where the inflammation sits: T cells killing basal cells in lichen planus, erythema multiforme and SJS/TEN, leaky vessels round mast cells in urticaria, and plugged, inflamed follicles in acne and rosacea.7 steps · 10 questions · 3D anatomy
  22. PH-SD22Purulent skin infectionsSkin infections sorted by the layer they reach: impetigo in the epidermis, boils down the hair follicle, erysipelas and cellulitis in the dermis, necrotising fasciitis along the fascia, and the staphylococcal toxin that splits the epidermis.8 steps · 10 questions · 3D anatomy
  23. PH-SD23Viral skin infectionsHow viruses that infect the epidermis make warts, molluscum and herpes vesicles, why shingles follows one dermatome, and why the rashes of measles, rubella, parvovirus B19, roseola and hand, foot and mouth disease look and time as they do.8 steps · 10 questions · 3D anatomy
  24. PH-SD24Pemphigus, pemphigoid and cutaneous lupusWhere the split or deposit sits: antibodies against desmosomes split the epidermis from within in pemphigus, hemidesmosome antibodies lift it off in pemphigoid, IgA lodges in the dermal papillae in dermatitis herpetiformis, and lupus inflames the junction.6 steps · 10 questions · 3D anatomy
  25. PH-SD25Skin vasculitis and panniculitisHow immune complexes in the dermal venules cause palpable purpura and lasting wheals, why vessel depth reveals vessel size, and how inflammation of the fat septa (erythema nodosum) differs from lobular panniculitis that kills fat.7 steps · 10 questions · 3D anatomy