BIOE 533 5.1

• The cardiovascular system transports nutrients and chemical signals to the tissues and removes waste materials and heat.
• In the cardiovascular system, the medium of transport is the blood.
• In the cardiovascular system, the final exchange of materials occurs across the walls of the capillaries from the blood to the interstitial fluid that bathes all cells of the body.
• The arteries take blood away from the heart, whereas the veins return blood to the heart.
• The heart consists of a dual pump. The right heart pumps blood through the pulmonary circulation, whereas the left heart pumps it through the systemic circulation.
• The pulmonary and systemic circulation are in series, whereas all other organs supplied by the systemic circulation are perfused in parallel.
• The three main components of the circulatory system are the heart, the blood vessels, and the blood.
• The heart contracts rhythmically to move blood from the veins at low pressure to the arteries at high pressure.
• Blood vessels are collectively called the vascular system.
• The blood vessels are of five major types:

  1. Large arteries.
  2. Arterioles.
  3. Capillaries.
  4. Venules.
  5. Major veins.
• The capillaries are tiny tubes that allow close but indirect contact of the blood with the tissues.
• In the capillaries, water, gas, and solute exchange between the blood and the tissues.
• The vascular system has four main functions:

  1. Transform the pulsatile flow from the heartbeat into a more continuous flow.
  2. Distribute the blood to various organs.
  3. Exchange materials in the tissues.
  4. Veins serve as volume reservoirs.
• In the blood is transported nutrients, wastes, chemical signals, and thermal energy. The primary material being transported to the cells is oxygen.
• What is convection?

  Convection is the movement of materials by flow.

  Convection is the part of the flux or transport of solute that occurs when solute is carried along by the bulk flux of fluid.
• Why is convection important?

  Convection increases the exchange of nutrients, wastes, chemical signals ,and thermal energy from blood to cells in large, multicellular animals.