Blood

Nota:

• haemoglobin (red) x4 O2 oxyhaemoglobin (purple)

1. Functions
   1. Temperature
   2. Temperature regulation
   3. Immunity
   4. Communication
2. Composition
   1. Plasma

      Nota:

      • 55%
   2. Red blood cells (erythrocytes)
   3. White blood cells (leucocytes)
   4. Platelets (thrombocytes)
3. Plasma

   Nota:

   • 55% of blood pale yellow liquid 92% water - 8% solutes antibodies clotting proteins transports materials e.g. glucose, vitamins, salt carries heat serum - without clotting proteins
4. Erythrocytes

   Nota:

   • red blood corpuscles bone marrow biconcave disc shape no nucleus no mitochondria rich in haemoglobin transports oxygen anaemia
5. Leucocytes

   Nota:

   • Defend the body against infection colourless no haemoglobin nucleus mitochondria some are phagocytes e.g. monocytes remove cell debris (some) produce antibodies (some) bone marrow + lymphatic tissue leukaemia
   1. Monocytes (macrophages)

      Nota:

      • Engulf pathogens, viruses, cancer cells, and tissues by phagocytosis formed in bone marrow 4-8% of the blood
   2. Lymphocytes

      Nota:

      • made in bone marrow and stored n parts of the lymphatic tissue e.g. spleen, lymph nodes, tonsils move using pseudopodia account for 20-25% of white blood cells produce antibodies
6. Platelets (thrombocytes)

   Nota:

   • not cells - no nucleus fragment of large bone marrow cells (megacytes) blood clotting chemicals bone marrow haemophilia
7. ABO blood grouping
   1. A

      Nota:

      • A antigens
   2. B

      Nota:

      • B antigens
   3. AB

      Nota:

      • A and B antigens
   4. O

      Nota:

      • no antigens
8. Rhesus factor

   Nota:

   • rhesus antigen - factor D RH + (antigen present) RH - (antigen absent) RH - can be donated to RH + but not the other way around A+/A RH+ A-/A RH-