Heart

Carry blood away from heart

Carry blood to the heart

• Incredibly small blood vessels connecting small arteries and small veins
• Site of most gas exchange between blood and tissue

Carried blood between heart and lungs

Carries blood between heart and rest of body

• Surrounds the heart and stabilizes it
• Epicardium (or visceral pericardium): lining sits right next to heart
• Parietal pericardium is outer lining

• Pericardial cavity filled with fluid secreted by membranes
• Fluid is lubricant for membranes as the heart beats

Inflammation of pericardium; membranes rub together and excess fluid collects in pericardial sac

• Receive blood
• Right atrium: receives blood from systemic circuit
• Left atrium: receives blood from pulmonary circuit
• Each has small extension (autricle)

• Pump blood
• Right ventricle: pumps blood into pulmonary circuit
• Left ventricle: pumps blood into systemic circuit

• Groove between different regions of the heart
• Coronary sulcus: separates atria and ventricles
• Anterior and posterior interventricular sulci: separate left and right ventricles

Part of the pericardium, made of epithelial cells and sometimes fat; blood vessels throughout

Cardiac muscle, nerve, blood vessels

Covers inner surface of heart wall

muscle fibers in heart create a swirl. When contracted, heart is like ringing out a shirt

Separates the right and left atria

Separates the right and left ventricles

Are found at junction between atria and ventricles and allow unidirectional fluid flow

Prevent backflow into ventricles

Prevents backflow into right ventricle

Prevents backflow into left ventricle

• Attach to valves to anchor them and keep them from opening in both directions
• Attached to papillary muscles, which control opening and closing of valves

When ventricles are relaxed to let blood into ventricles

Ventricles are contracting to let blood out of ventricles

• Receives blood from systemic circuit through two veins
• Superior Vena Cava: delivers blood from head, neck, upper limbs, and chest
• Inferior Vena Cava: delivers blood from lower trunk, viscera, and lower limbs

• Receives blood from right atrium through right AV (tricuspid) valve
• Has trabeculae carneae (musuclar ridges) along its internal surface
• Sends blood out to lungs through pulmonary valve,
• then pulmonary trunk, then left and right pulmonary arteries

Receives blood from two left and two right pulmonary veins

• Receives blood from left atrium through left AV (mitral or bicuspid) valve
• Very thick, muscular walls (bigger than right ventricle)
• Also has trabeculae carnae
• Blood exits left ventricle and enters systemic circuit and ascending aorta