Theme 4 - Blood and Immunity - Lecture 3 Flashcards
What is blood?
Made up of white, red blood cells and platelets
Suspended in a fluid called plasma
What does blood do?
Carries gas around the body, carries oxygen to our cells where they use it to produce energy (red blood cells)
Carries hormones, enzymes, nutrients and waste products around the body (plasma)
Clots blood to prevent blood loss following injury (platelets)
Defends us from infection (white blood cells)
Helps regulate body temperature
Maintains pH of body fluids
William Harvey (1578-1657)
- 1628: published a paper describing the circulatory system
- Later went on to describe and illustrate the action of valves in veins
History of Blood grouping and transfusion
Richard Lower (1631 - 1691)
- 1665: performed first recorded successful blood transfusion in dogs
- 1667: performed the first successful blood transfusion in humans, sheep-human transfusion in an attempt to cure insanity
James Blundell (1791 - 1878)
- 1818: performed first successful human-human transfusion
Karl Landsteiner (1868 - 1943)
- 1901: observed that often, but not always, a blood transfusion would results in blood clumping in the recipient’s circulation
- 1909: classified the ABO system of blood typing
- 1904: identified the rhesus antigen
How is blood used?
Clinical transfusion for he living and dying
- whole blood, red blood cells, plasma, platelets
- Identification: forensic/paternity
Blood types
4 main blood types:
A, B, AB, O
Further classified as positive (+) or negative (-) so 8 types in total
Blood types are determined by which antigen is found on RBC. A antigen, B Antigen, AB antigens, O (neither A nor B antigens)
What is an antigen?
Marker on a cell surface that confers information about a cell’s identity to the immune system
What is an Antibody?
produced by B lymphocytes which are primed to recognise specific antigen markers on
Antibodies bind with antigens to cause clumping of blood cells (agglutination) in vitro and haemolysis in viva
Lymphocytes
If they recognise the antigen as its self it will ignore the cell
If they recognise the antigen with a foreign cell, it will undergo an immune attack to destroy it
What is agglutination?
Is when antibodies bind with antigens to cause clumping of blood cells in vitro and haemolysis in vivo
The Rhesus Grouping
The +/- classification of blood is determined by the presence or absence of the Rhesus antigen on RBC. If the RBC’s express the Rhesus antigen the blood is rhesus positive (Rh+ve) while the absence of the rhesus antigen makes the blood rhesus negative (Rh-ve)
