Pathology and Microbiology
This section tests disease mechanisms, tissue responses, and infection control principles that determine physiotherapy precautions and contraindications.
Core rules and concepts
- Cell injury may be reversible or irreversible; necrosis types include coagulative, liquefactive, caseous, and fat necrosis.
- Acute inflammation: vasodilatation, increased permeability, neutrophil emigration, and chemical mediators.
- Healing by primary intention occurs in clean apposed wounds; secondary intention occurs with tissue loss and granulation.
- Virchow triad for thrombosis: stasis, endothelial injury, hypercoagulability.
- Granuloma formation in tuberculosis; acid-fast bacilli and caseous necrosis are characteristic.
- Sterilisation destroys all microorganisms including spores; disinfection reduces pathogens on inanimate surfaces.
Worked example
A patient develops unilateral calf swelling and pain after hip surgery. Reasoning: postoperative immobility causes venous stasis, surgical trauma causes endothelial injury, and surgery increases clotting factors, satisfying Virchow triad. The physiotherapist should not perform vigorous deep massage or uncontrolled exercise; these could dislodge a thrombus. The patient needs urgent medical review for duplex ultrasound and anticoagulation. Mobilisation and compression follow medical clearance and local protocol.
Traps that cost marks
- Calling a transudate an exudate; exudate has high protein and cells, as in inflammation.
- Confusing sterilisation with disinfection; only sterilisation kills spores.
- Assuming every granuloma is tuberculosis; fungi and foreign bodies also cause granulomas.
- Ignoring systemic signs of infection before electrotherapy or exercise.