chapter 34 Flashcards
leukocytes wbc and where they are made
The leukocytes, also called white blood cells, are the
mobile units of the body’s protective system. They are
formed partially in the bone marrow (granulocytes and
monocytes and a few lymphocytes) and partially in the
lymph tissue (lymphocytes and plasma cells)
6 types of wbc
neutrophils eosinophils basophils monocytes lymphocytes platelets sometimes plasma cells
% of all types of wbc
Polymorphonuclear neutrophils 62.0% Polymorphonuclear eosinophils 2.3% Polymorphonuclear basophils 0.4% Monocytes 5.3% Lymphocytes 30.0%
major lineage of wbc formed by the hemopoietic stem cells
myelocytic lineage and lymphocytic lineage
monocytes and granulocytes are made in
bone marrow
lymphocytes and plasma cells are made in
lymphoid tissues like tonsils, thymus, lymph glands, spleen bone marrow and payers patch underneath the epithelium of gut
what cells mainly destroy the invading bacteria, virus and harmful agents
neutrophils and macrophages
2 ways by which wbc moves through tissues
- through diapedesis which is through small gaps in endothelial cells in capillaries and postcapillary venules
- amoeboid movement
- chemotaxis
3 selective procedures
- normal cells of the body are smooth which resist phagocytosis
- normal cells of the body have a protective protein coat
- the immune system of the body makes antibody which adhere to bacterial membrane and makes it more susceptible to phagocytosis
antibody made by immune system adheres to what else than bacterial membrane
it adheres to C3 of complement cascade and these C3 molecules in turn attach to receptors on phagocyte membrane initiating phagocytosis
opsonization
the process through which a pathogen is selected for phagocytosis and destruction is called as opsonization
phagocytocsis my neutrophils
neutrophil attaches itself to the particle and the pseudopodia projects in all directions, the pseudopodia fuses together and form an enclosed chamber with phagocytized particle in it
then it invaginates the particle inside the cytoplasm it breaks away from outer cell membrane and form a free floating particle
Once Phagocytized, Most Particles Are Digested by
Intracellular Enzymes.
Once a foreign particle has been
phagocytized, lysosomes and other cytoplasmic granules
in the neutrophil or macrophage immediately come in
contact with the phagocytic vesicle, and their membranes
fuse, thereby dumping many digestive enzymes and bactericidal agents into the vesicle. Thus, the phagocytic
vesicle now becomes a digestive vesicle, and digestion of
the phagocytized particle begins immediately
the lysosome of macrophage contains
lipids to digest the thick lipid membrane of bacteria like tuberculosis bacillus
both neutrophils and macrophages lysosomes are filled with
proteolytic enzymes
how neutrophils and macrophages kill bacteria other than digestion of phagocytosed bacteria
they kill by releasing bactericidal agents that kill bacteria which were failed to be digested by lysosomes.
this is done by oxidizing agents produced by peroxisome and membrane of phagosome
oxidizing agnest are
superoxide, hydrogen peroxide, hydroxyl ions and myeloperoxidase which catalyzes the reaction between hydrogen peroxide and chloride to form hypochlorite which is highly bactericidal
reticuloendothelial cells
total combination of monocytes, attached macrophages, mobile macrophages and some endothelial cells of bonemarrow, spleen and lymph nodes make up the reticuloendothelial cells
what is inflammation
when a tissue is damaged or undergoes a trauma because of heat chemicals or any other phenomena the tissues that are undamaged undergo secondary changes called inflammation
Inflammation is characterized by
(1) vasodilation of
the local blood vessels, with consequent excess local
blood flow; (2) increased permeability of the capillaries,
allowing leakage of large quantities of fluid into the
interstitial spaces; (3) often clotting of the fluid in the
interstitial spaces because of increased amounts of fibrinogen and other proteins leaking from the capillaries; (4)
migration of large numbers of granulocytes and monocytes into the tissue; and (5) swelling of the tissue cells.