Lecture 15 Cardiovascular System

Cardiovascular system

Heart + blood vessels; circulates blood to meet body cell needs

Cells need

Oxygen and nutrients

Arteries

Carry blood away from the heart

Veins

Carry blood toward the heart

Capillaries

Exchange of gases and nutrients between blood and tissues

General blood flow

Heart → Arteries → Capillaries → Veins → Heart

Heart

Hollow, 4-chambered organ that pumps blood

Heart chambers

2 atria and 2 ventricles

Two sides of the heart

Right side pumps to lungs; left side pumps to body

Great vessels

SVC, IVC, pulmonary trunk, aorta

Heart valves

2 AV valves and 2 semilunar valves

Location of heart

Thoracic cavity within mediastinum

Heart orientation

Base superior; apex points inferiorly and left

Pericardium

3-layer sac surrounding the heart

Fibrous pericardium

Outer layer that protects and anchors the heart; prevents overfilling

Parietal pericardium

Lines inside of fibrous pericardium

Visceral pericardium / Epicardium

Covers heart surface

Pericardial cavity

Space filled with fluid to reduce friction

Epicardium

Smooth outer surface of the heart

Myocardium

Middle layer of cardiac muscle; responsible for contraction

Endocardium

Smooth inner lining of heart chambers; continuous with blood vessels

Coronary arteries

Supply heart tissue with oxygenated blood

Right coronary artery branches

Right marginal artery and posterior interventricular artery

Left coronary artery branches

LAD (anterior interventricular), circumflex, left marginal artery

Coronary sinus

Veins drain here and empty into right atrium

Right atrium receives blood from

SVC, IVC, coronary sinus

AV valves

Tricuspid (right) and bicuspid/mitral (left)

Semilunar valves

Pulmonary and aortic valves

Trabeculae carneae

Muscular ridges in ventricles

Papillary muscles

Anchor AV valves using chordae tendineae

Pulmonary circulation

Right heart → lungs → left heart

Systemic circulation

Left heart → body → right heart

Ascending aorta branches

Right and left coronary arteries

Three branches of aortic arch

Brachiocephalic trunk, left common carotid, left subclavian

Superior vena cava drains

Head, neck, thorax, upper limbs

Inferior vena cava drains

Abdomen, pelvis, lower limbs