Pre-clinical medicine
Physiology
Physiology is the study of how the body works: how the heart pumps, how nerves signal, how hormones control growth and stress. It explains normal function so that doctors can recognise what goes wrong in disease, including in the brain.
Depth by stage, Pre-U → Consultant (details)
What is it?
Physiology follows anatomy closely: once students know the structures, they learn how they work. It covers cells, nerves and muscles, the heart and circulation, breathing, kidneys, digestion, hormones and reproduction.
Much of it is about control systems, the ways the body keeps blood pressure, temperature, blood sugar and salt levels stable. When those controls fail, disease follows.
In Malaysian medical schools, physiology is usually taught in integrated system blocks with anatomy and biochemistry.
Why does a psychiatrist need it?
Mental illness and its treatments affect the whole body. Stress activates the hypothalamic-pituitary-adrenal axis; anxiety causes racing heart and breathlessness; thyroid problems can mimic depression or anxiety; many psychiatric drugs alter heart rhythm, weight, blood sugar or sodium. Physiology lets the psychiatrist understand these links and monitor patients safely.
What level is expected at each stage?
Scale: 1. Aware → 2. Understands → 3. Applies → 4. Masters / Teaches. What the levels mean.
- Pre-UAwareAware of basic body functions from school biology.
- Pre-clinicalAppliesApplies physiological principles in exams and practical class experiments.
- ClinicalUnderstandsUnderstands how disease disturbs normal physiology at the bedside.
- HousemanshipAppliesApplies physiology daily: fluids, electrolytes, blood pressure, oxygen.
- Medical officerUnderstandsUnderstands physiology relevant to the posting; uses it in monitoring.
- Psych traineeUnderstandsUnderstands neurophysiology and endocrinology in depth for basic sciences exams; links physiology to side-effect monitoring.
- Specialist / consultantUnderstandsUnderstands enough to manage physical complications of illness and treatment, with medical colleagues.
What are the key topics?
Cells, nerves and muscle
- Membrane potentials and action potentials
- Synaptic transmission
- Skeletal, cardiac and smooth muscle
- The autonomic nervous system: sympathetic and parasympathetic
Cardiovascular and respiratory
- Cardiac cycle and the ECG (including the QT interval)
- Blood pressure control
- Breathing control and gas exchange
- Hyperventilation and its symptoms (link to panic attacks)
Renal and fluid balance
- Kidney filtration and tubular function
- Sodium and water balance (link to hyponatraemia from some antidepressants)
- Acid-base balance
- How lithium is handled by the kidney (introduction)
Endocrine physiology
- Hypothalamus and pituitary
- Stress response and cortisol (the HPA axis)
- Thyroid function
- Insulin, glucose and metabolism
- Prolactin control (link to antipsychotic side effects)
Brain and behaviour
- Sleep and circadian rhythms
- Hunger, thirst and temperature regulation
- Pain pathways
- Sensory physiology: vision and hearing
How is it learned and assessed?
- Lectures and problem-based learning (PBL) cases
- Practical classes and simulations (for example, ECG and spirometry)
- MCQ, short-answer and practical examinations in each block
- Neurophysiology and endocrinology revisited in MMed Part I and MRCPsych Paper A
Typical textbooks and resources
- Guyton and Hall Textbook of Medical Physiology — Hall and Hall (Elsevier)
- Ganong's Review of Medical Physiology — McGraw Hill
- Human Physiology: From Cells to Systems — Lauralee Sherwood (Cengage)
- Physiology at a Glance — Wiley-Blackwell
Titles are widely used examples; editions change. Use university libraries or legitimate purchases.
Common questions
How is physiology linked to mental health?
Many symptoms of anxiety and depression are physical, from palpitations to poor sleep and appetite. Physiology explains these and also helps doctors check that a psychiatric picture is not caused by a physical illness such as an overactive thyroid.
Is physiology hard?
Students often find it demanding because it requires understanding, not just memorising. It becomes easier when linked to real clinical cases, which is why many schools teach it through PBL.