the circulatory system

• the circulatory system is made up of blood, the heart and blood vessels
• the circulatory system's main function is to transport substances around the body
• the three blood vessels are:

  • arteries
  • capillaries
  • veins
• the circulatory system had two systems:

  • pulmonary circulation
  • systemic circulation
• pulmonary circulation sends blood from the heart to the lungs and back
• systemic circulation sends blood to the rest of the body and back to the heart
• in pulmonary circulation:

  • the lungs are where the oxygen and nutrients are picked up by the blood
  • carbon dioxide and waste is released from blood into lungs
  • this happens in the alveoli (air sacs) of the lungs
• systemic circulation provides organs, tissues and cells with blood, so they get oxygen and nutrients
• blood has 4 components:

  • red blood cells
  • white blood cells
  • platelets
  • plasma
• red blood cells:

  • makes up 50%-60% of your blood
  • contains hemoglobin
• hemoglobin carries oxygen and makes blood red
• white blood cells:

  • fight infection
  • only abt 1% of blood
• platelets:

  • used to cloth
  • very thick and sticky (stick tgt)
  • less than 1% of your blood
• plasma:

  • 47% of your blood
  • protein rich liquid
• arteries:

  • carry blood away from heart
  • thick walls
• veins:

  • carry blood toward heart
  • pressure low so thin walls
• capillaries:

  • tiny blood vessels which allow substances to diffuse between blood and other body fluids
  • tissues link together arteries and veins
• heart:

  • cardiac muscle contracts and allows blood to move around the body
  • heart rate changes depending on physical activity
  • epithelial tissue covers heart
• heart is made up of four chambers:

  • right atrium
  • right ventricle
  • left atrium
  • left ventricle
• valves are located between each chamber in the heart
• valves of the heart:

  • control the flow of blood through heart by opening and closing during contractions
  • allows blood to flow in only one direction
• atherosclerosis is the hardening of the arteries due to plaque
• heart attack is the blockage of blood flow
• prolapsed valves cause backwards flow of blood
• arrhythmia is an abnormal heart rate
• high blood pressure makes the heart work harder