Core concept
Interdependence of systems
No system works alone: a change in one system is sensed and answered by others.
No organ system works alone. Your heart pumps, but your kidneys set how much blood it has to pump, your nervous system sets its rate, and your lungs load the blood it carries with oxygen. A change in one system is sensed and answered by others.
This is why a single problem spreads. After heavy bleeding, the heart speeds up, the blood vessels tighten, the kidneys hold on to water and the thirst center pushes you to drink, all to protect blood pressure. When you study a system, ask what it depends on and what depends on it.
Where it shows up
Orientation to the body
Nerves, reflexes and pathways
- The neurological exam
The endocrine system
- Other endocrine organs
The cardiovascular system
- Short-term blood pressure regulation
- Long-term blood pressure regulation
- Hypertension, heart failure and shock
Lymphatic and immune systems
- Immune disorders
The respiratory system
- Respiratory disorders
The urinary system
- Urine, clearance and kidney hormones
Fluid, electrolyte and acid–base balance
- Regulating acid–base balance
- Acid–base disorders and compensation
Development and inheritance
- Maternal changes during pregnancy
- Newborn adjustments and lactation
- Aging across the body