Circulatory system(organ system)

• Circulatory system


  transports oxygen and nutrients to our body’s tissues
• Circulatory system


  • Relies on 3 main things: Blood- carries the all important oxygen and nutrients. Blood vessel- hold that blood. The heart- pumps blood to keep it moving through the vessels
• Blood flow through the circulatory system

  1. Deoxygenated Blood flows from heart to lungs, gains oxygen, flows back to heart

  2. Oxygenated blood flows from heart to body, gives up oxygen to the tissues, flows back to heart
• Heart


  Consists of 4 chambers with thick muscular walls, veins and arteries
• When looking at a diagram of the heart, the left side is on the right and the right side is on the left
• Atria


  Top chambers of the heart
• Ventricles

  Bottom chambers of the heart
• Valves


  Prevent blood from flowing backwards, ensure blood flows in the right direction
• Blood flow through the heart


  1. Flows into right atrium and left atrium

  2. Atria contract, push blood into ventricles

  3. Ventricles contract, push blood into pulmonary artery and aorta

  4. Atria refill with new blood, cycle repeats
• Pacemaker cells


  Group of cells in the right atrium that produce electrical impulses to make the heart contract
• Artificial pacemaker


  Small device implanted under the skin above the heart, with a wire that carries electrical current to the heart
• Artery


  Any vessel that carries blood away from the heart
• Vein


  Any vessel that carries blood to the heart
• Arteries don't always carry oxygenated blood, and veins don't always carry deoxygenated blood
• Coronary arteries


  Small arteries that branch off the aorta and encircle the heart to supply it with oxygenated blood
• What is A?

  The pulmonary artery

  
• What is B?

  The vena cava

  
• What is C?

  Right atrium

  
• What is D?

  The heart valve

  
• What is E?

  Tendons attached to valve and heart wall

  
• What is F?

  Right ventricle

  
• What is G?

  Left ventricle

  
• What is H?


  Heart valve

  
• What is I?


  Left atrium

  
• What is J?


  Pulmonary vein

  
• Artery adaptation 


  Arteries have a very thick wall to withstand and maintain the high blood pressures generated from the heart
• Veins adaptation


  low blood pressure so they have thinner walls
• The heart acts as the pump for the circulatory system
• Blood vessels


  1. Arteries carry blood away from the heart

  2. Capillaries exchange nutrients and oxygen with tissues

  3. Veins carry blood back to the heart
• Arteries


  • Carry blood away from the heart
  • Blood inside is at high pressures
  • Have thick layers of muscle and elastic tissue to be strong and elastic
• Capillaries


  • Very small vessels that come into close contact with cells
  • Walls are only one cell thick and permeable
  • Total cross-sectional area is much larger than arteries, so blood flows more slowly
• Veins


  • Relatively large vessels with the biggest lumens
  • Walls are thin with small layers of elastic fibers and smooth muscle
  • Have valves to prevent backwards blood flow
• Calculating rate of blood flow

  Divide volume of blood by time taken