The Cardiovascular System

Fun Facts About The Heart The heart pumps 1.3 gallons (5L) per MINUTE! 2,000 gallons a DAY Weighs less than 1lbs Size of your fist 72-82 beats per MINUTE 3 billion beats per LIFETIME Apex directed toward left hip, and rest on diaphragm

Functions Of the Cardiovascular System Maintenance of body’s pH levels (acids and bases Removal of CO2 & other wastes Assistance with immune function TRANSPORTATION Oxygen Nutrients Hormones Gases EVERYTHING! Regulation of body temperature through vasoconstriction and vasodilation.

Four Chambers of the Heart Atria – on top Collecting chambers Atrium is singular! Ventricles – on bottom Powerful pumps Left ventricle has thickest wall because it pumps blood to rest of body!

Atrioventricular (AV) Valves Located between the atrial and ventricular chambers Left AV Valve: Bicuspid (Mitral) valve 2 cusps Right AV Valve: Tricuspid valve 3 cusps OPEN during heart relaxation and CLOSED when ventricles contracting

The Valves The heart is equipped with four valves… Allow blood to flow in only ONE direction through the heart chambers Have cusps (flaps) that open & close

The Valves AV valves have chordae tendinae (“heart strings”) which are connected to papillary muscles. Each time the ventricle contracts, the papillary muscle pulls the AV valve closed

FYI: Why the special name for the bicuspid valve? Early anatomists thought that the bicuspid (mitral) valve looked like a bishop’s miter (their funny hat)

Semilunar Valves Guards the bases of the two large arteries leaving the ventricular chambers Pulmonary Semilunar Valve (right) Aortic Semilunar Valve (left) Both have THREE cusps CLOSED during heart relaxation and OPEN when ventricles contracting Blood Circulation Heart Valves

Second heart sound or “dub” - Aortic and pulmonary semilunar valves close at beginning of ventricular diastole

Heart Supporting Structures Superior Vena Cava: carries oxygen-poor blood from body to heart (right atrium) Inferior Vena Cava: carries oxygen- poor blood from body to heart (right atrium)

Heart Supporting Structures Pulmonary trunk: carries oxygen-poor blood from heart (right ventricle) to pulmonary arteries Pulmonary arteries: carries oxygen-poor blood from pulmonary trunk to lungs Only artery to carry O2 poor blood!

Heart Supporting Structures Pulmonary Veins: carries oxygen-rich blood from lungs to heart (left atrium) Only vein to carry O2 rich blood! Aorta: carries oxygen- rich blood from heart (left ventricle) to body Largest artery in body

The heart does 2 types of circulation… Pulmonary Circulation Leaves from right side of heart Delivers CO2 waste to lungs, and picks up O2 to take back to heart Returns to left side of heart Systemic Circulation Leaves from left side of heart Delivers O2 and nutrients to body, and picks up CO2 to take back Returns to right side of heart

Blood Supply to Heart The blood supply that oxygenates and nourishes the heart itself (myocardium) is provided by the right & left CORONARY ARTERIES, which branch from the base of the AORTA and encircle the heart in the ATRIOVENTRICULAR GROOVE.

Coronary arteries branch off from the base of the aorta Right Coronary Artery breaks into… Posterior interventricular (on back side of heart) Marginal Left Coronary Artery breaks into… Anterior interventricular Circumflex

Blood Supply to Heart The heart (myocardium) is drained by several CARDIAC VEINS, which empty into the CORONARY SINUS, which in turn, empties into the RIGHT ATRIUM.

Cardiac Veins include… Great cardiac vein Anterior cardiac vein Small cardiac vein Middle cardiac vein (on posterior side of heart)

Labeling The Heart A: Aortic Arch (Aorta) B: Superior Vena Cava C: (Right) Pulmonary Veins D: Right Atrium E: Tricuspid Valve AB: Right Ventricle AC: Inferior Vena Cava

Labeling The Heart AD: (Left) Pulmonary Artery AE: Left Atrium BC: Bicuspid (Mitral) Valve BD: Aortic Semilunar Valve BE: Left Ventricle CD: Aorta

Labeling The Heart Let’s Also Label… Pulmonary Trunk Pulmonary Semilunar Valve Septum Apex