Physiology and Human Development
Core concepts
Physiology explains how the body maintains homeostasis - a stable internal environment through negative feedback. Learn the key systems: the cardiovascular system (cardiac cycle, blood pressure, pulse), the respiratory system (gas exchange, ventilation), the renal system (fluid and electrolyte balance), the endocrine system (hormones and their effects), and thermoregulation. Understand vital signs ranges for adults: respiratory rate, pulse, blood pressure, oxygen saturation, temperature and level of consciousness. Human development spans the lifespan: infancy, childhood, adolescence, adulthood and older age. Know Piaget's cognitive stages, Erikson's psychosocial stages, and attachment theory (Bowlby, Ainsworth). Recognise age-related changes such as reduced renal function, loss of bone density, and changes in hearing and vision.
Traps in questions
Do not confuse negative feedback (restoring balance) with positive feedback (amplifying a change, e.g. childbirth). Remember that normal ranges vary with age: infants have faster respiratory and heart rates. Questions may test Maslow's hierarchy and expect you to identify the priority need. Watch for confusion between growth (increase in size) and development (increase in skill and complexity).
Worked rule of thumb
For any physiological disturbance, use the stimulus–sensor–control–effector chain. Example: a rise in body temperature is detected by the hypothalamus, which triggers sweating and vasodilation to lower temperature - negative feedback.
Applying it
Recognising normal ranges and deviations is central to detecting deterioration early and escalating appropriately.