Pulmonary Circuit Systemic Circuit - from heart to lungs back to heart - from heart to body back to heart

Heart Tissue Pericardial Sac Fibroskeleton Surface Structures Valves (one-way-flow) The Heart

Position and Orientation of the Heart

Pericardial Sac and Location of the Heart in the Thoracic Cavity

Epicardium –Visceral pericardium Endocardium –Epithelium of inner surface Myocardium –Muscular wall of the heart

The Fibrous Skeleton Is an internal connective tissue of the heart 1. Provides attachment for heart’s valves 2. Evenly distributes the force of contraction 3. Electrically isolates atria from ventricles

Surface Anatomy of the Heart

Sectional Anatomy of the Heart

The Atria Right Atrium receives blood from systemic circuit: 1) Superior vena cava 2) Inferior vena cava 3) Coronary Sinus Walls of both Atria have Pectinate muscles. Foramen ovale open in utero – closes to become the Fossa ovalis after birth. Left Atrium receives blood from pulmonary circuit: From L and R Pulmonary veins.

The Ventricles Blood comes from atria through atroventricular (AV) valves: –Tricuspid AV valve (Rt) and Bicuspid AV valve (Lt) Blood leaves via pulmonary truck (Rt) and aorta (Lt) –Pulmonary semilunar valve –Aortic semilunar valve Chordae Tendineae Papillary Muscles Trabeculae Carneae

Valves of the Heart How do papillary muscles work?

Heart Valves and Heart Sounds Closure of the AV valves create the 1 st heart sound (‘lub’). Closure of the semilunar valves create the 2 nd heart sound (‘dupp’). Stethoscope Placement

Coronary Circulation

Circulation

Fetal Circulation