1. S1: Answer - Closure of AV valves (tricuspid and mitral) -"Lub" corresponds with carotid pulse, loudest at apex 2. S2: Answer -Closure of semilunar valves (aortic and pulmonic) -Loudest at base;sounds like "Dup" 3. S1 split: Answer Tricuspid and mitral valves closing asynchronously 4. S2 split: Answer Aortic and pulmonic valves closing asynchronously 5. S3: Answer -Sound immediately following S3; "Kentucky" -Physiological: children, fit adults > 30 -Ventricular resistance to filling during rapid filling phase -Volume overload (HF, valve, regard, increase CO, e.g., PG) -Pathologic or due to pregnancy 6. S4: Answer -Sound immediately before S1; "Tennessee" -Ventricular resistance to filling at end of diastole -Decrease compliance (Cardiomyopathy, CAD), Systolic overload (aortic stenosis), HTN