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Nicole's Med Terms
Nicole's Med Terms
Medical Terminology
The cardiovascular system is a closed-loop delivery system. The heart pumps oxygenated blood through arteries to tissues, and veins return deoxygenated blood to the heart. The pulmonary circuit handles gas exchange in the lungs; the systemic circuit serves the rest of the body. Cardiovascular disease remains the #1 cause of death worldwide.
The heart is a hollow, muscular pump the size of a fist, located in the mediastinum (middle of the chest).
Four Chambers:
Four Valves (prevent backflow):
The heart wall: epicardium (outer), myocardium (muscle), endocardium (inner lining)
Outer sac: pericardium
Arteries: Carry oxygenated blood away from heart (exception: pulmonary arteries carry deoxygenated blood). High pressure, thick walls, elastic.
Veins: Carry deoxygenated blood toward heart. Lower pressure, thinner walls, contain valves to prevent backflow.
Capillaries: Microscopic vessels where exchange of gases, nutrients, and wastes occurs between blood and tissues.
Blood flow: Heart → Arteries → Arterioles → Capillaries → Venules → Veins → Heart
The heart beats approximately 60–100 times per minute at rest (bradycardia <60; tachycardia >100).
Cardiac Conduction System:
1. SA node (sinoatrial node) — the natural pacemaker
2. AV node (atrioventricular)
3. Bundle of His
4. Left and right bundle branches
5. Purkinje fibers
Blood pressure measurement (*sphygmomanometer*):
Coronary Artery Disease (CAD): Atherosclerosis of coronary arteries → angina or MI
Myocardial Infarction (MI/Heart Attack): Blockage → ischemia → infarction (tissue death)
Heart Failure: Heart can't pump enough blood to meet body's needs
Arrhythmias: Atrial fibrillation (AFib), ventricular fibrillation (VFib)
Hypertension: Silent killer; damages vessels and end-organs over time
Diagnostic Tests:
Interventions: