12. Blood: Leucocytes and Plasma proteins Flashcards
What are the functions of white blood cells?
Immune response
Inflammatory
Disposal of damaged and ageing
What is the two classifications of leucocytes?
Polmorphonuclear granulocytes
Mononuclear agranulocytes
What are the features of polymorphonuclear granulocytes and what are examples of this?
irregular, multi-lobed nuclei
Posses cytoplasmic granules
Basophils, eosinophils, neutrophils
What are features of mononuclear argranulocytes and examples?
Large, regular nuclei
Lack cytoplasmic granules
Lymphocytes
Monocytes
What are the features of neutrophils?
Multilobed nucleus Inconspicous cytoplasmic granules Specialist in destroying bacteria Short life span Migrate to areas of infection Phagocytic
What are the events leading to phagocytosis?
- Activation of resting phagocytes by inflammatory mediators
- Movement of phagocytes towards chemical attractants
- Margination, rolling and adhesion
- Diapedesis
- Recognition- attachment of phagocyte to pathogen
- Ingestion
- Pathogen
What are the features of eosinophils?
Bi-lobed nucleus
Red cytoplasmic granules
Migrate to areas of infection
Less active as phagocytes when compared to neutrophils
Degranulation releases toxic substances aiding defense against larger parasites
Increased inallergic disease
Prolonged elevations lead to tissue damage
What are features of basophils?
Bi-lobed nucleus
Large purple cytoplasmic granules
Less active as phagocytes when compared to neutrophils & esoinophils
Release chemicals at site of infection
- histamine & other mediators of inflammation
- heparin, an anticoagulant
Involved in allergic responses
Involved in parasitic responses
Attract other WBCs
Migrate to areas of infection (chemotaxis)
Similar to tissue mast cells
What are the three main types of lymphocytes?
T-cells
B-cells
Natural Killers
What are the features of lymphocytes?
Spherical nucleus
Pale blue cytoplasm
20-40% WBCs
BUT, small percent of total lymphocytes in body
Others are outside blood vessels within the body
Non-phagocytic
Mount immune response by direct cell attack or via antibodies
What is the role of T-cells?
Coordinate immune response
Attack foreign cells directly
Increase/decrease other lymphocytes
What are the four types of t-cells?
Cytotoxic T-cells
Helper t-cells
Regulatory T-cells
Memory T-cells
What is the role of cytotoxic t-cells?
Destroy virally infected cells and tumour cells, and are also implicated in transplant rejection
What is the role of helper t-cells?
Assist the other white blood cells in immunologic processes
What is the role of regulatory T-cells?
Formerly known as supressor T-cells are crucial for the maintenance of immunological tolerance
What is the role of memory T-cells?
Subset of antigen -specific T-cells that persist long term after an infection has been removed
What is the role of B- cells?
To provide humoral immunity
Attachment of antigen to receptor on surface of B cell leads to activation
Become plasma cells- secrete antibodies
Become memory B cells
What do natural killer cells do?
Kill infected/ cancerous cells
Cytoplasmic granule contents released
Perforate cell membrane
Cause cells to initiate
What are the features of monocytes?
U/kidney shaped Blue cytoplasm Phagocytic Attract other WBCs and fibroblasts After 72 hours enter tissues and become macrophages
What are examples of some tissue-specific macrophages?
Alveolar and peritoneal macrophages Kuppfer cells Osteoclasts Microglial cell in brain Histiocytes
What is the composition of plasma?
7%- plasma proteins
1% other solutes
92% Water
What is the function of solutes?
electolytes and organic nutrients/wastes
What is the function of water in the plasma?
Transports organic and inorganic molecules, formed elements, and heat
What is the difference between plasma and serum?
Serum is blood without the clotting factors
What are the types of proteins in plasma?
Albumin
Globulin
Firbrinogen
How is albumin transported?
Fats Amino Acids Enzymes Drugs e.g. warfarin Non-specific
How is globulin transported?
Ions
Hormones
Vitamins
Different classes carry different substances*
How does albumin regulate fluid composition?
Exert plasma onctic pressure
How does fibrinogen restrict fluid loss?
Functions in blood clotting
How does globulin defend the body against pathogens?
Gamma globulins are antibodies
