Heart Anatomy and Blood Flow

Overview of the Heart

• The heart is the circulatory system's central component
• It continuously pumps blood
• The heart delivers oxygenated blood and nutrients to tissues
• It removes wastes and returns deoxygenated blood to the lungs
• Understanding blood flow is essential for understanding cardiac conditions

Basic Terminology

• Veins carry blood to the heart
• Arteries carry blood away from the heart
• Blue indicates deoxygenated blood
• Red indicates oxygenated blood

Heart Structure

• The heart has four chambers
• The upper chambers are atria, and the lower chambers are ventricles
• The chambers are the right atrium, right ventricle, left atrium, and left ventricle
• Atria load ventricles before ejection
• The right heart side sends deoxygenated blood to the lungs
• The left heart side receives oxygenated blood from the lungs
• There are four heart valves at each chamber's exit
• The tricuspid valve exits the right atrium
• The pulmonic valve exits the right ventricle
• The mitral (bicuspid) valve exits the left atrium
• The aortic valve exits the left ventricle
• Valves prevent backflow
• Normal valves have three leaflets, except the mitral valve, which has two

Blood Vessels

• Blood vessels bring blood to and from the heart
• The inferior vena cava carries blood from the trunk, visceral organs, and lower body
• The superior vena cava carries blood from the head and upper body
• The vena cavae empty deoxygenated blood into the right atrium
• The pulmonary artery carries deoxygenated blood to the lungs
• The pulmonary veins carry oxygenated blood from the lungs to the left atrium
• The aorta carries oxygenated blood to the body

Blood Flow

• Deoxygenated blood returns via the inferior and superior vena cavae
• Blood empties into the right atrium
• The right atrium contracts, moving blood through the tricuspid valve to the right ventricle
• The right ventricle contracts, ejecting blood through the pulmonic valve into the pulmonary artery
• The pulmonary artery carries blood to the lungs for oxygenation
• Oxygenated blood returns via the pulmonary veins
• Pulmonary veins empty into the left atrium
• The left atrium contracts, moving blood through the mitral valve to the left ventricle
• The left ventricle contracts, ejecting blood through the aortic valve into the aorta
• The aorta distributes blood to the body

Mnemonic for Heart Valve Order

• Use "TPMA"
• T: Tricuspid
• P: Pulmonic
• M: Mitral
• A: Aortic