Cardiovascular System
1. Heart Anatomy – In-Depth 1.1 External Anatomy Located in the middle mediastinum , apex pointing to 5th intercostal space midclavicular line Surfaces: Sternocostal : RA & RV predominantly Diaphragmatic : LV and some RV Pulmonary (left) : LV impression on left lung Borders: Right: RA Left: LV and auricle Superior: Base – LA and great vessels Pericardium: Fibrous pericardium : tough outer layer, attached to diaphragm and sternum Serous pericardium: Parietal layer: lines fibrous pericardium Visceral layer (epicardium): on heart surface Pericardial cavity: 15–50 mL of lubricating fluid Clinical correlation: Pericardial effusion → cardiac tamponade; auscultation changes 1.2 Internal Anatomy Chambers & Wall Thickness: | Chamber | Wall Thickness (mm) | Relative Function ||---------|-------------------|-----------------|| RA | 2–3 | Low pressure reservoir || RV | 3–5 | Pumps to pulmonary circulation || LA | 2–4 | Receives pulmonary venous blood || LV | 8–12 | Pump...