Heart transport videos

• Important components of the human circulatory system


  • Blood
  • Heart
  • Blood vessels
• Plasma


  The yellowish liquid part of blood that suspends the blood cells
• Types of blood cells

  • Red blood cells
  • White blood cells (lymphocytes and phagocytes)
  • Platelets
• Red blood cells

  • Also known as erythrocytes
  • Made in the bone marrow
  • Carry oxygen around the body
  • Biconcave shape for large surface area to volume ratio
  • Contain hemoglobin to bind and transport oxygen
• White blood cells

  • Protect the body against pathogens
  • Phagocytes engulf and digest bacteria
  • Lymphocytes produce antibodies
• Lymphocytes develop into memory cells


  Can recognise pathogens and mount a faster immune response if exposed again
• Vaccination

  • Exposes the body to a dead, weakened or modified pathogen
  • Allows the body to learn how to make antibodies against that pathogen
  • Enables a faster secondary immune response if exposed to the real pathogen
• Platelets

  Form blood clots to stop bleeding and prevent infection
• Plasma

  • Mostly water (90%)
  • Carries dissolved substances like amino acids, glucose, cholesterol, antibodies, hormones, carbon dioxide, lactic acid, urea
  • Distributes heat around the body
• Cardiac muscle


  • Special type of muscle that makes up the heart
  • It is different from muscle in the arms, legs, intestines and guts
  • It never gets tired
  • It pumps blood around the body and to the lungs by contracting and relaxing
• Cardiac cycle

  1. Blood enters the atria

  2. Blood passes down into the ventricles as the tricuspid and bicuspid valves are shut

  3. Atria contract, forcing blood down through the open valves into the ventricles

  4. Ventricles contract from bottom up (ventricular systole), forcing blood out of the arteries as the tricuspid and bicuspid valves shut

  5. Ventricles relax, semilunar valves close to prevent backflow, atria start filling with blood again
• Atria


  The two upper chambers of the heart
• Ventricles


  The two lower chambers of the heart
• Vena cava


  Blood vessel carrying deoxygenated blood back to the heart from the body
• Aorta


  Blood vessel carrying oxygenated blood out of the heart to the body
• Pulmonary artery


  Blood vessel carrying deoxygenated blood from the heart to the lungs
• Pulmonary vein


  Blood vessel carrying oxygenated blood from the lungs back to the heart
• Blood


  Flows to almost every single cell in the body through a network of vessels
• Types of blood vessels

  • Arteries
  • Veins
  • Capillaries
• Coronary arteries


  Arteries that supply the heart muscle itself with oxygen and glucose
• valves

  Valves in the major arteries leaving the heart that prevent backflow of blood
• Arteries

  • Carry blood away from the heart to the organs
  • Tend to carry oxygenated blood
  • Have thick walls full of muscle and elastic fiber
  • Have a small lumen to maintain high pressure
• Bicuspid valve


  Valve between the left atrium and left ventricle
• Tricuspid valve


  Valve between the right atrium and right ventricle
• Veins

  • Carry blood back to the heart from the organs
  • Carry deoxygenated blood
  • Have thin walls with little muscle or elastic tissue
  • Have a large lumen to allow low pressure blood flow
  • Contain valves to prevent backflow
• When exercising

  Heart rate increases to deliver more oxygen to respiring muscles and remove more carbon dioxide
• Capillaries


  • Carry blood to individual cells
  • Have permeable walls to allow exchange of materials
  • Are only one cell thick
• Major blood vessels supplying organs

  • Pulmonary artery and vein (lungs)
  • Hepatic artery, hepatic portal vein, hepatic vein (liver)
  • Renal artery and vein (kidneys)
• Coronary heart disease


  Condition where a fatty plaque builds up in the coronary arteries supplying the heart muscle
• Causes of coronary heart disease


  • Smoking
  • High cholesterol
  • High blood pressure
  • Family history
  • Lack of exercise
• Plaque buildup in coronary arteries

  Can lead to blood clots that block the artery and cause a heart attack