Circulatory System - Blood

The Four Main Components of Blood:

  • Red Blood Cells- red blood cells are made up of 95% hemoglobin and are large microscopic cells without a nucleus.
  • They make up about 40-50% of blood.
  • Red Blood Cells transport oxygen around the body from the lungs and are created in the bone marrow with 2-3 million cells every second.
* White Blood Cells live for 18-36 hours and have many different kinds.
  • They make up about 1% of blood
  • Most of white blood cells are produced in the bone marrow
  • White blood cells are the protectors of our bodies and will destroy foreign cells by "eating" them

  • Platelets- viable for 9-10 days
  • They are cell fragments without nuclei and they help with blood clotting chemicals
  • Can aid in the help of fighting infection
  • They stimulate the immune system and are 1/3 the size of red blood cells

  • Plasma- made up of about 90% water and 10% sugar, lipids, proteins, vitamins, minerals, hormones, enzymes, and clotting agents
  • Carries platelets, red blood cells and white blood cells
  • Brings nourishment to cells and removes waste
  • Plasma is the liquid portion of blood

Blood Clotting:
  • Blood Clotting- blood cells and fibrin strands form clumps to stop bleeding
  • A clot eventually becomes a protective scab
  • If blood did not clot then we would bleed to death from a single cut
  • Becomes dangerous when they block the blood flow in an artery