Anatomy, Physiology and Applied Sciences
Anatomy, physiology and applied sciences test structure–function relationships that underpin nursing assessment: cell physiology, cardiovascular, respiratory, renal, nervous and endocrine systems.
Core rules
- Cardiac output = heart rate × stroke volume; blood pressure is influenced by cardiac output and systemic vascular resistance.
- Respiratory gas exchange occurs at the alveoli; surfactant reduces surface tension and prevents collapse.
- The kidney filters plasma at the glomerulus; the renin–angiotensin–aldosterone system raises blood pressure and conserves sodium.
- The autonomic nervous system: sympathetic “fight or flight” increases heart rate and dilates pupils; parasympathetic slows the heart and promotes digestion.
- Endocrine feedback: low thyroid hormone increases TSH; high cortisol suppresses ACTH.
Worked example
A patient with vomiting and diarrhoea has raised plasma osmolality. Osmoreceptors stimulate ADH release, the collecting ducts reabsorb more water, and urine becomes concentrated. Reasoning: ADH defends plasma osmolality, not blood volume directly; volume is defended by RAAS and baroreceptors.
Traps
Mixing sympathetic and parasympathetic effects; confusing ADH with aldosterone; forgetting that the left lung has two lobes and the right three; reversing the direction of endocrine feedback.