Unit 1

• What is the primary function of the circulatory system?

  To circulate fluids through the body
• What type of circulatory system do most mammals have?

  Closed circulatory system
• What are the three main parts of a circulatory system?

  Fluid, tubes (blood vessels), and a pump (heart or specialized vessel)
• What is the fluid called that circulates in the circulatory system?

  Blood
• How does blood travel in a closed circulatory system?

  Blood remains inside tubes called blood vessels
• What is the role of the heart in the circulatory system?

  The heart pumps blood around the body under high pressure
• What happens to substances in the tissues of the body?

  Substances diffuse from the blood into body cells
• What are capillaries?

  The smallest blood vessels in the body
• What useful substances diffuse into body cells from the blood?

  Oxygen and food
• What waste products diffuse back into the blood from the tissues?

  Carbon dioxide and waste products
• Why is a closed circulatory system considered efficient?

  Because the movement of blood can be easily controlled
• What are the two circulatory systems in the human body?

  The pulmonary and systemic circulatory systems
• What does double circulation mean?

  Blood passes through the heart twice in one circuit of the body
• What is the function of the pulmonary circulatory system?

  To carry blood from the heart to the lungs and back to the heart
• What is the function of the systemic circulatory system?

  To carry blood from the heart to the body and back to the heart
• What are the key components of a closed circulatory system?

  • Blood: the fluid that circulates
  • Blood vessels: tubes for circulation
  • Heart: the pump for circulation
• How do the pulmonary and systemic circulatory systems work together?

  • Blood is pumped from the heart to the lungs (pulmonary circuit)
  • Blood is oxygenated in the lungs
  • Oxygenated blood returns to the heart
  • Blood is pumped from the heart to the rest of the body (systemic circuit)
• What is the process of diffusion in the circulatory system?

  • Substances move from blood into body cells
  • Useful substances like oxygen and nutrients enter cells
  • Waste products like carbon dioxide exit cells into the blood
• What is the significance of high pressure in the closed circulatory system?

  • Ensures efficient blood flow
  • Facilitates the delivery of oxygen and nutrients
  • Aids in the removal of waste products