Lecture 4 Flashcards
What are the general functions of blood?
- Transport- nutrient, oxygen, waste, CO2
- Osmotic pressure (H2O and electrolytes)
- Buffering pH (acid-base balance)
- Haemostasis (platelets and coagulation factors)
- Immunity (leukocytes)
What is the major site of reed blood cell production within the body?
Bone marrow
Describe the difference between the proliferative and the maturative pools:
Proliferative is where they are dividing into more cells. Whereas the maturative stage is where they have already differentiated.
What are the two different types of progenitor cells and what time of blood cells do these eventually become?
- Common lymphoid progenitor cells- T cells, B cells and NK cells. These originate within the bone marrow however they mature in the lymphatic tissues (B cells- spleen, T cells in the thymus
- Common myeloid progenitor cells- these will eventually become the platelets, erythrocytes, monocytes and neutrophils, eosinophils and the basophils
Describe the kinetics of erythrocytes:
- Erythropoetin = the primary growth factor that is involved in the proliferation and differentiation of colony forming erythrocytes
- Erythroid development occurs with central macrophages releasing positive and negative growth factors
What is the lifespan of erythrocytes? (i.e is it days, months, years) .
months
Describe the function of neutrophils:
• Defence against invading micro-organisms, primarily bacteria
Recognise inflammatory signals
Leave the blood
Migrate through tissue to site where bacteria are present
Describe the basics of neutrophil kinetics:
- Neutrophils in the blood are typically in transit from the site of function or destruction
- Storage neutrophil pool- segmented neutrophils ready for release to marrow sinusoids
- Blood neutrophils- free flowing in blood; however, some of these do stick to the endothelial walls. Ratio is normally one however for cats this ratio is actually 3:1
Describe the function of eosinophils and basophils:
- Half-life 8-10 hrs
- Eosinophils have less phagocytic ability than neutrophils providing very poor host defence
- Important part of type-2 cytokine induced inflammatory response (responsible for type 1 hypersensitivity allergic reactions)
Describe the kinetics of monocytes:
• Half life is variable among species
• Marginated pool
• Migrate to tissue
Macrophages- survive up to 3 months
Dendritic cells- antigen presenting cellsDescribe the basic functioning of monocytes:
• Th 1 response Potent antimicrobial properties Promote inflammation • Th 2 response Wound repair Tissue remodelling Immunomodulation
Describe the functioning of platelets:
• Involved in the clotting response more information is available in the second lecture
Describe the differences between B cells and T-cells (including maturation sites in the answer):
- T cells originate from the thymus, B cells originate from the bone marrow
- T cells involved in adaptive immunity, B cells mainly present the antigen or foreign substance to the cell
Using the cat as the example explain the concept of blood groups and why these are important when transfusing blood from one animal to another:
• Multiple different blood groups for cats and dogs exist
• These include
-Type A
-Type B
-Type AB
-Naturally occurring isoantibody against the antigen they lack
• Type A recipient = low anti-B-hemagglutinins transfusion from a type B donor = 1/3rd agglutination and haemolysis
• Type B recipient = high anti-A-hemagglutinins transfusion from a type A donor = massive transfusion reaction
• Type AB = no isoantibodies against either A or B antigens transfusions are safe from type A or type B donors
Why do we not need to worry about our first transfusion when we are transfusing blood to a dog?
Dogs do not have naturally occurring antibodies and hence we do not need to worry about the first transfusion.
