Circulatory System

• Protista exchange gases through diffusion
• Three main functions of the human circulatory system

  • Transport gases (O2 & CO2), nutrients and waste
  • Regulate internal temperature and transport hormones
  • Protect against blood loss from injury and against disease-causing microbes and/or toxic substances
• Three major components of the circulatory system

  • Heart
  • Blood
  • Blood vessels
• Not all animals have a heart
• Pulmonary Circulation


  1. Carries oxygen-poor blood from heart to lungs

  2. Carries oxygen-rich blood from lungs to heart
• Systemic Circulation


  1. Carries oxygen-rich blood from heart to body tissues

  2. Carries oxygen-poor blood from body tissues to heart
• Artery


  Blood vessel that takes blood away from the heart
• Vein


  Blood vessel that takes blood towards the heart
• Varicose Veins


  • Improper functioning valves
• Length of the longest vessel (straw) that could be sucked up liquid
• Since we have thousands of meters of vessels, a pump is required
• Stem cells grown in the lab form cardiac tissue and start beating. 2015.
• Atria


  Upper chambers of the heart
• Ventricles


  Bottom chambers of the heart
• Septum


  Thick muscular wall that separates the right and left ventricles
• Enlarged heart (cardiomegaly)


  • Caused by damage to the heart muscle or any condition that makes the heart pump harder than usual, including pregnancy and prolonged high blood pressure
  • Sometimes the heart gets larger and becomes weak for unknown reasons. This condition is called idiopathic cardiomyopathy.
• 'An enlarged heart is beneficial.' Agree or disagree with this statement and provide reasons for your choice.
• Blood Flow


  1. Start in the right atrium

  2. Through tricuspid AV valve

  3. Right ventricle

  4. Pulmonary arteries

  5. Lungs (drop off CO2, pick up O2)

  6. Pulmonary veins

  7. Left atrium

  8. Bicuspid AV valve

  9. Left ventricle

  10. Aortic valve (semilunar valve)

  11. Aorta to body capillaries

  12. Superior vena cava

  13. Inferior vena cava
• Where capillaries are found in mammals

  • Lungs
  • Body tissues
• Blood leaving the heart towards the lungs is oxygenated
• Blood leaving the heart through the aorta is oxygenated
• Vessels that allow blood to leave the heart to go towards the lungs

  Pulmonary arteries
• Vessels that allow the blood to leave the lungs to return to the heart

  Pulmonary veins
• In mammals, the left half of the heart contains oxygen rich blood
• In mammals, the right half of the heart contains oxygen poor blood
• The chamber of the heart with the thickest, strongest walls

  Left ventricle
• The four heart valves

  • Tricuspid AV valve
  • Bicuspid AV valve
  • Semilunar valve (pulmonary)
  • Semilunar valve (aortic)
• Heart murmur


  A "leaky" valve that allows blood to backflow
• Heart Structure


  • Chambers that fill with blood returning from lungs (left) or body (right)
  • Chambers that receive blood from the atria and pump it either to the lungs (right) or the body (left)
  • Muscular wall that separates the ventricles and separates oxygenated and deoxygenated blood
  • Collects oxygen poor blood from the head, chest and arms
  • Collects oxygen poor blood from elsewhere in the trunk and legs
  • The blood vessels that carry blood from the right ventricle to the lungs. Deoxygenated blood.
  • The blood vessels that carry blood back from the lungs to the left atrium. Oxygenated blood.
  • The largest blood vessel in the body that leaves the left ventricles and carries blood out to the body. Very high pressure.
  • The atrioventricular valve that has three flaps and separates the right atrium from the right ventricle.
  • The atrioventricular valves that has two flaps and separates the left atrium from the left ventricle.
  • The valves that are half-moon in shape and are found both in the pulmonary trunk (splitting of the pulmonary arteries) and the aorta.
• Coronary Circulation: The heart tissue itself requires oxygenated blood. Coronary arteries provide blood from the aorta.
• Coronary Angiography


  Visualizing blockages in the coronary arteries
• Atherosclerosis


  Build up of consumed fat or cholesterol
• Treatment for atherosclerosis


  1. Inflated balloon to widen the narrowing and/or place a permanent structure, called a stent to ensure widening

  2. Coronary bypass surgery
• Hypoplastic Left Heart Syndrome (HLHS) is a birth defect that affects normal blood flow through the heart. As the baby develops during pregnancy, the left side of the heart does not form correctly.
• "Lubb - dubb" sounds

  Heart muscle contraction
• Heart muscle contraction is initiated

  By the stimulation of embedded nerve fibers in the wall of the right atrium, called the sinoatrial (SA) node
• The electrical signal from the SA node stimulates the walls of both atria to contract simultaneously.
• Electrocardiogram (EKG)


  Electrical machine that can observe the electrical activity of the heart
• The Beating Heart
• Coronary bypass surgery


  Treatment for coronary artery disease