Write the tabular classification of leucocytes of human body
Answers
Answer:
MARK ME AS BRAINLIEST
Explanation:
Types of Leukocytes
There are five distinct classes of leukocytes (white blood cells) that coordinate to provide defence against infectious disease:
Neutrophils
Most abundant type of white blood cell and the first responder to microbial infection
They are unable to renew their lysosomes and die after having phagocytosed a few pathogens (forms the majority of pus)
Analogy: Standard police officer – quick to respond to the situation, but lacks special training or skills and so dies rapidly
Eosinophils
Prominent at the sites of allergic reactions and parasitic infections (rare in blood but common at mucous membranes)
Do not phagocytose pathogens but instead release chemical products which perforate cell membranes
Consequently, they function as the primary response to large multicellular parasites (e.g. helminth infections)
Analogy: Fumigator – specialised to deal with pests / parasites (e.g. helminths) by releasing chemical products
Basophil
Basophils are chiefly responsible for initiating inflammatory responses by releasing the chemicals histamine and heparin
Functionally they are similar to mast cells, however they circulate in the bloodstream whereas mast cells are localised
Because they promote inflammation, they are common contributors to allergic responses
Analogy: Fireman – the leukocyte involved when a region is inflamed (‘in flames’)
Monocyte
Monocytes are the largest type of leukocyte and share phagocytosis duties with neutrophils
They are slower to respond than neutrophils but are longer lasting, as they can renew their lysosomes for continued digestion
Monocytes will differentiate into two types of cells in response to pathogenic infection – macrophages and dendritic cells
Macrophages will remain in the tissue and phagocytose, whereas dendritic cells present antigen fragments to lymphocytes
Analogy: Riot police (macrophage) – slower to respond than standard police but better prepared and survives for longer
Analogy: Signalman (dendritic cell) – identifies the pathogen and sends signals to the appropriate special forces (lymphocytes)
Lymphocyte
Lymphocytes are responsible for the production of antibodies which target specific antigens present on pathogens
They are more common in the lymphatic system than blood and are slowest to respond (requiring antigen presentation)
Lymphocytes include B cells (which become antibody-secreting plasma cells) and T cells (which mediate B cell activity)
Lymphocytes are also involved in the destruction of virus-infected body cells (via cytotoxic T cells and natural killer cells)
Analogy: Special forces / superheroes – takes longest to mobilise but specially trained to target specific pathogens