Blood Flow in the Heart

Blood Flow and Circulation

• Deoxygenated blood from the body enters the right atrium of the heart via the superior and inferior vena cavae.
• Atrial contraction (atrial systole) forces blood into the tricuspid valve and flows into the right ventricle.
• Ventricular contraction (ventricular systole) closes the tricuspid valve and opens the pulmonary valve, pumping deoxygenated blood to the lungs via the pulmonary artery.

Pulmonary Circulation

• In the lungs, there is an exchange of gases, where blood picks up oxygen and releases carbon dioxide, becoming oxygenated blood.
• Oxygenated blood returns to the left side of the heart via the pulmonary veins, entering the left atrium.

Systemic Circulation

• Atrial contraction in the left atrium forces blood into the left ventricle.
• Ventricular contraction in the left ventricle closes the mitral valve and opens the aortic valve, pumping oxygenated blood out to the rest of the body through the aorta.

Aorta

• The aorta is the largest artery in the body, consisting of four parts:
  • Ascending Aorta
  • Aortic Arch (gives rise to major arteries supplying blood to the head, neck, and upper extremities)
  • Descending (thoracic) Aorta
  • Abdominal Aorta (supplies blood to abdominal organs and gives off various branches)

Coronary Sinus

• The coronary sinus is a vein located in the coronary sulcus on the posterior side of the heart.
• It collects blood from the great, middle, and small cardiac veins before emptying into the right atrium.
• This process allows for the efficient removal of metabolic waste and replenishment of oxygen in the myocardium.