L4.2.4: Pumping Mechanisms

• PUMPING MECHANISMS

  ● The heart functions as a double pump

  ○ ARTERIES carry blood away from the heart

  ○ VEINS carry blood toward the heart

  ○ Note: In general, arteries carry oxygenated blood while veins carry deoxygenated blood. The important exceptions are the pulmonary arteries as they carry deoxygenated blood to the lungs, and the pulmonary veins as they carry oxygenated blood
• PUMPING MECHANISMS

  ● Mechanism of the double pump

  ○ Right side works as the pulmonary circuit pump

  ○ Left side works as the systemic circuit pump
• PULMONARY CIRCULATION

  ● Blood flows from the right side of the heart to the lungs and back to the left side of the heart

  ● Function: to carry blood to the lungs for gas exchange; oxygen enters, carbon dioxide leaves
• PULMONARY CIRCULATION

  ● Inferior and superior vena cavae

  ○ Receive deoxygenated blood

  ● Pulmonary trunk

  ○ Pumps and splits into pulmonary arteries and takes deoxygenated blood to the lungs

  ● Pulmonary veins

  ○ Return oxygenated blood to the heart
• SYSTEMIC CIRCULATION

  ● Blood flows from the left side of the heart through body tissues and back to the right side of the heart

  ● Function: deliver oxygenated and nutrient-rich blood to the entire body

  ○ Therefore, the left ventricle needs thicker walls for more work
• SYSTEMIC CIRCULATION

  ● Aorta

  ○ Pumps out oxygenated blood received by the left atrium

  ○ Blood circulates to systemic arteries and to all body tissues