Blood Flow Through The Heart

Blood Flow Through The Heart

• The heart is the circulatory system's powerhouse.
• It continuously moves blood all over the body.
• Oxygenated blood and nutrients are provided.
• Waste products are removed.
• Deoxygenated blood is returned to the lungs.
• Understanding blood flow is key to understanding blood-flow related conditions.

Basic Foundations

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

Heart Structures

• There are four main chambers: two atria (upper) and two ventricles (lower).
• The heart includes the right atrium, right ventricle, left atrium, and left ventricle.
• Atria ensure ventricles are fully loaded prior to ejection.
• The right side of the heart circulates deoxygenated blood to the lungs.
• The left side of the heart circulates oxygenated blood from the lungs.

Heart Valves

• There are four heart valves, one at each chamber's exit.
  • Tricuspid valve: Located at the exit of the right atrium.
  • Pulmonic valve: Located at the exit of the right ventricle.
  • Mitral valve (bicuspid): Located at the exit of the left atrium.
  • Aortic valve: Located at the exit of the left ventricle.
• Valves function as one-way passages, preventing backflow.
• Normal valves have three leaflets, except for the mitral valve, which has two (bicuspid).

Vessels

• The inferior vena cava transports deoxygenated blood from the trunk, visceral organs, and lower body.
• The superior vena cava transports deoxygenated blood from the head and upper body.
• Both empty into the right atrium.
• The pulmonary artery transports deoxygenated blood away from the heart and to the lungs.
• The right and left pulmonary veins transport oxygenated blood back to the heart, emptying into the left atrium.
• The aorta transports oxygenated blood away from the heart to the rest of the body.

Blood Flow Steps

• Deoxygenated blood enters the heart through the inferior and superior vena cava, emptying into the right atrium.
• The right atrium then contracts, moving blood through the tricuspid valve and into the right ventricle.
• The right ventricle contracts, forcing blood through the pulmonic valve into the pulmonary artery.
• The pulmonary artery transports blood to the lungs for oxygenation.
• Oxygenated blood flows back to the heart via the pulmonary veins, emptying into the left atrium.
• The left atrium contracts, moving blood through the mitral valve into the left ventricle.
• The left ventricle contracts, ejecting blood through the aortic valve into the aorta for distribution to the rest of the body.

Mnemonic

• TPMA is a helpful device device for remembering the sequence of the heart valves: tricuspid, pulmonic, mitral, aortic.