CIE IGCSE Biology: 复习笔记:9.1.14 Components of Blood

CIE IGCSE Biology: 复习笔记:9.1.14 Components of Blood

Components of Blood

  • Blood consists of red blood cells, white blood cells, platelets and plasma

Composition of human blood

Components of the Blood Table

Identifying Red & White Blood Cells

  • You need to be able to identify red and white blood cells in photomicrographs and diagrams
    • Red blood cells have a concave disc shape with no nucleus
    • White blood cells are usually round in shape with a nucleus

Blood micrograph

Components of Blood: Function

  • Plasma is important for the transport of carbon dioxide, digested food (nutrients), urea, mineral ions, hormones and heat energy
  • Red blood cells transport oxygen around the body from the lungs to cells which require it for aerobic respiration
    • They carry the oxygen in the form of oxyhaemoglobin
  • White blood cells defend the body against infection by pathogens by carrying out phagocytosis and antibody production
  • Platelets are involved in helping the blood to clot