1. Cardiovascular Details & Anatomy
The system operates as a closed loop, with the heart acting as a central, four-chambered muscle.
- The Heart: A fist-sized muscular organ (myocardium) with two upper atria (receivers) and two lower ventricles (pumps).
- Blood Vessels:
- Arteries: Carry oxygen-rich blood away from the heart.
- Veins: Return oxygen-poor blood to the heart using one-way valves.
- Capillaries: Tiny vessels where the exchange of gases and nutrients occurs.
- Circuits: Pulmonary (to lungs) and Systemic (to body).
2. System Properties
- Muscular Pump: Cycles through systole (contraction) and diastole (relaxation).
- Electrical Conduction: Coordinated by the sinoatrial (SA) node.
- Vasodynamics: Ability to use vasodilation and vasoconstriction to regulate flow.
3. Core Functions
- Transport: Delivery of O2 and nutrients.
- Protection: Immune defense via white blood cells.
- Regulation: Maintains body temperature and pH balance.
4. Cardiovascular Health
A healthy system delivers blood efficiently at appropriate pressures.
- Key Indicators: Blood pressure (~120/80 mmHg), healthy cholesterol, and steady heart rate.
- Common Conditions: Hypertension, Coronary Artery Disease, Arrhythmias, and Heart Failure.