Blood function Flashcards
What are the 3 key functions of the blood?
Transport
Regulation
Protection
What are the 4 features of transport?
- Respiration
- Nutrient carrier from GIT
- Transportation of hormones form endocrine gland
- Transport of metabolic waste
What are the 3 features of regulation?
- Regulation of pH
- Regulation and maintenance of body temperature
- Maintenance of cells’ water content
What are the 3 features of Protection?
- WBC protect against disease by phagocytosis
- Reservoir for substances such as water, electrolytes, etc
- Haemostasis
What is the composition of blood?
Plasma (55%)
Buffy coat- leukocytes and platelets (<1% of whole blood)
Erythrocytes (45% of whole blood)
What is whole blood?
- Slightly alkaline (pH- 7.35-7.45)
- 8% of body weight
- 5x more viscous than water
What is plasma?
- Straw coloured and sticky
- 55% of bodies total blood volume
- 90% water
- Solutes include proteins and non-proteins
What is the composition of plasma?
- Albumin (60%)
- Globulins (35%)
- Fibrinogen (4%)
- Other (<1%)
What are the features of albumin?
- Globular protein
- Synthesised in liver
- Plasma conc of 35-50mg/mL
- 19 day half life
What is the function of albumin?
- Maintains oncotic pressure
- Controls pH
- Binding and transport- hormones, nutrients, metal ions, drugs, etc
What is a1 globulin?
a1- antitrypsin
Important in inflammation
What is a2 globulin?
Example= hepatoglobin, facilitates Hb clearance
a2- macroglobin, antiprotease binds to cytokines & GF
What is b-globin?
Example: transferrin, iron binding & transport
Plasminogen pre-cursor of plasmin & WBC migration
What is y- globin?
IgG (75%), IgA (15%), IgM (10%), IgD (0.2%), IgE (0.002%) fight off infection
What is Fibrinogen?
2nd Haemostasis, wound healing, inflammation, forms fibrin fibres- used for blood clotting
What is the other <1%?
- Coagulation factors & inhibitors
- Electrolytes
- Nutrients
- Hormones
What are Leukocytes?
White blood cells
What are Erythrocytes?
RBC
What are Thrombocytes?
Platelets
What do Haematopoietic stem cells form?
Common myeloid progenitor
OR
Common lymphoid progenitor
What do common myeloid progenitors form?
Erythrocytes
Mks= platelets
Myeloblasts
What do myeloblasts form?
Basophil
Neutrophil
Eosinophil
Monocyte
What does common lymphoid progenitor form?
Lymphoblast
What does a lymphoblast form?
T or B lymphocyte
What are agglutinogens?
Antigens
Specific proteins located on RBC wall- basis for blood group classification
What are Agglutinins?
Antibodies
Plasma antibodies that act against agglutinogens not present on a persons own RBC
What is the universal recipient?
AB+
What is the universal donor?
O-
what is Rhesus (Rh) blood group
- Based on ion- channel antigen on RBC membrane
- Rh- more common in the west (15%) than in Asia or Africa (1%)
What is the humoral reaction to Transfusions?
Blood from type A donor
Type B recipient
Donor RBCs agglutinated by recipient plasma
Agglutinated RBCs block small vessels
What is the cellular reaction to Transfusion?
Immune cells
What is the Haemolytic disease of the Newborn (HDN)
First pregnancy= Protected by the placenta blood barrier, mother not exposed to Rh agglutinogens until the time of childbirth
Second pregnancy= Antibodies cross barrier, child born with severe anemia
What is the treatment for HDN?
Use anti- Rh gamma globulin to mask Rh agglutinogens
What is Primary Haemostasis?
-Damage to blood vessel wall
- Vasoconstriction
- Platelet adhesion & activation
- Granule release- increase conc of platelet activators, coagulation factors, vasoconstrictors
- Platelet plug formed
What is secondary Haemostasis?
damage to blood vessel wall
formation of “sticky” platelet plug
formation of insoluble fibrin clot
What is the activation of coagulation?
Intrinsic pathway FXII
Extrinsic pathway FVII
Common pathway FX
Fibrinogen- Fibrin
Crosslinking formed
Where does anticoagulation act?
Intrinsic pathway & Common pathway
Where does Fibrinolysis (plasmin) occur?
Fibrin
What is TXA?
Fibrinolysis inhibitor
Stops breakdown of fibrin fibres
Stops rapid bleeding
