Biomedical Sciences for OPRA: Physiology, Pathophysiology and Microbiology

Weight and time budget

The 20% weight is the APC's. Unscored calibration items are spread across all five areas, so the number of scored questions here is about 22 and the question count of about 24 is a planning figure. Of the five areas, this is the second largest after therapeutics. At 75 seconds per question, the block represents about 30 minutes of the exam.

Because the APC says 55% of questions across the exam test recall, biomedical sciences is where careful memorisation earns reliable marks. It is also the area where overseas courses differ most. A pharmacist trained in a programme with a strong clinical pharmacy emphasis may have thin physiology, and one trained in a basic-science programme may have thin pathophysiology. Your baseline block will show which you are.

What is tested

• Normal physiology by system. Cardiac cycle, valves and blood pressure regulation. Respiratory physiology and acid-base balance. Renal function, nephron segments and the sites of diuretic action. Gastrointestinal and hepatic function. Endocrine axes: thyroid, adrenal, pituitary, parathyroid. Reproductive physiology and the menstrual cycle. Nervous system and neurotransmitters. Bone and musculoskeletal metabolism. Haematology, including anaemias, the clotting cascade and fibrinolysis.
• Pathophysiology of common disease. Heart failure, atherosclerosis and arrhythmias. Diabetes mellitus and metabolic disorders. Asthma, COPD and pulmonary embolism.
• Medical microbiology. Bacteria and the Gram stain, resistance mechanisms, and an overview of viruses, fungi and parasites.
• Immunology. Hypersensitivity types, autoimmunity and transplant rejection.
• Disorders of bodily fluids. Sodium, potassium, calcium and magnesium disturbances, and acid-base disorders.
• Symptoms and physiological values. Laboratory reference ranges and what abnormal values suggest.
• Other topics in our list. Cancer biology and tumour markers, genetics relevant to drug therapy, inflammation, pain pathways and thermoregulation.

The subtopic list is our grouping of the APC's headings into study units. The APC does not publish a list at this level of detail.

Local points

OPRA does not test Australian law, so local points here are about presentation and convention.

• Units: laboratory values appear in SI units such as mmol/L and micromol/L. If you learned reference ranges in mg/dL, convert them and learn the SI numbers.
• Spelling: anaemia, oesophagus, haemoglobin, paediatric. Misreading a term because of spelling is rare, but be comfortable with it.
• Reference ranges: the APC exam guide does not give ranges. Use a current Australian laboratory or textbook source and learn the common ones to the level a stem would require, such as whether a potassium is low, normal or high.
• Immunisation: vaccine content may link to immunology. The Australian Immunisation Handbook is the reference if a question draws on schedules; see references and conventions.

Three typical traps

1. Learning physiology without the drug link. A stem about the nephron is often really a question about where a diuretic acts, or about what happens to potassium when it does. After each system, write down which drug classes act on it and how.
2. Mixing up direction of change. Questions about acid-base and electrolytes reward careful direction: what rises, what falls, and what compensates. Sketch the chain before choosing. Candidates who rush choose the opposite effect.
3. Treating microbiology as a list. Memorising organism names without the features that separate them, such as Gram stain, shape, typical site of infection and resistance mechanism, leaves you unable to answer when the stem gives only a description.

Self-check before you move on

You are ready to leave this block when you can do each of the following without notes. If you cannot, return to that point before taking more mixed blocks.

• Draw the cardiac cycle and say what changes in pressure and volume at each phase.
• Name the nephron segment where each diuretic class acts and predict the effect on sodium and potassium.
• State what compensation occurs for a primary respiratory or metabolic acid-base disorder.
• Place the intrinsic, extrinsic and common clotting pathways and say where warfarin and heparin act.
• Classify the four hypersensitivity types with one example of each.
• Separate Gram-positive from Gram-negative organisms by one key feature, and name one resistance mechanism for each.
• List the usual cause and feature of high and low sodium, potassium and calcium.

Do not treat this list as a prediction of what will be asked. It is a test of whether your foundations are firm enough to support pharmacology and therapeutics.

How to revise this area

1. Study by system, one a day. Normal function in the morning, then disease and the drugs that act on it. Finish with 20 questions.
2. Draw, do not just read. Redraw the nephron, the clotting cascade and the cardiac cycle from memory and check against the source.
3. Build compact tables. Hypersensitivity types, anaemia types, electrolyte disorders (cause, features, treatment), Gram-positive and Gram-negative groups.
4. Link to pharmacology. For every receptor, enzyme or channel, note a drug that targets it. This is where biomedical and pharmacology marks reinforce each other.
5. Revisit weekly. Use short recall quizzes on the earlier systems. Recall decays quickly when you move on.

Within a 12-week plan, this block takes about two weeks. See the study plan. The APC's other weighted areas are on the OPRA hub.