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.
Some of the many tissue products that cause these reactions
e histamine, bradykinin, serotonin, prostaglandins,
several different reaction products of the complement
system,, reaction products of
the blood clotting system, and multiple substances called
lymphokines that are released by sensitized T cell
first result of inflammation is
is to “wall off” the area of injury
from the remaining tissues. The tissue spaces and the
lymphatics in the inflamed area are blocked by fibrinogen
clots so that after a while, fluid barely flows through the
spaces. This walling-off process delays the spread of bacteria or toxic products.
first line of defense is done by?
macrophages be with sessile, or alveolar macrophages, microglia or histiocytes in the subcutaneous tissues. this happens within minutes after inflammation
second line of defense is done by and through what
it is done within few hours of inflammation and done by neutrophils. the inflamed area release the tumor necrosis factor or interleukin-1 which inflammatory cytokines
what is margination in 2nd line of defense
They cause increased expression of adhesion molecules, such as selectins and intercellular adhesion
molecule–1 (ICAM-1) on the surface of endothelial
cells in the capillaries and venules. These adhesion
molecules, reacting with complementary integrin
molecules on the neutrophils, cause the neutrophils
to stick to the capillary and venule walls in the
inflamed area. This effect is called margination
what are the other two things that is done to initiate the neutrophil invasion
the intercellular adhesion between capillaries and venules is loosen up so the neutrophil can move though diapedesis easily
also though chemotaxis of the neutrophil towards the inflamed
extravasation
translocation though capillaries into the tissues is called extravasation
diapedesis
movement of blood cells though the intact walls of capillaries or usually is used with extravasation when blood cell moves from capillaries into the tissue
neutrophilia
which means an increase in the number of neutrophils in the blood
neutrophilia is causes by?
Neutrophilia is caused by products of
inflammation that enter the blood stream, are transported
to the bone marrow, and there act on the stored neutrophils of the marrow to mobilize these into the circulating
blood
3rd line of defense
second invasion by macrophages
4th line of defense is done by
granulocytes and monocytes which are stimulation of granulocytic and monocytic progenitor cells of bone marrow which can take 3-4 days to reach the inflamed area from the bone marrow
implicated in control of the macrophage response to
inflammation, five of these are believed to play dominant roles which are
f (1) tumor necrosis factor (TNF), (2) interleukin-1
(IL-1), (3) granulocyte-monocyte colony-stimulating factor
(GM-CSF), (4) granulocyte colony-stimulating factor
(G-CSF), and (5) monocyte colony-stimulating factor
(M-CSF).
The cause of increased production of granulocytes and
monocytes by the bone marrow is mainly the three
colony-stimulating factor which are
GM-CSF, stimulates both granulocyte and monocyte production; the
other two, G-CSF and M-CSF, stimulate granulocyte and
monocyte production, respectively. This combination of
TNF, IL-1,
formation of pus
a cavity is excavated in the inflammed tissue which contains dead macrophages and neutrophils, necrotic tissues and tissue fluid. this is called as pus
eosinophils are produced in large number in people who have?
parasitic infection
how eosinophils destroy parasites
they attached on the parasitic molecules through special structures and release substances that can kill many of parasites
example of most common parasite
schistosomiasis which affect 1/3rd of population of africa asia and south america. 90% of the worlds cases are in africa
how eosinophils kills parasites
- by releasing hydrolytic enzymes from their modifies lysosomes.
- by releasing highly reactive form of oxygen
- by releasing a larvicidal polypeptide called major basic protein
a person who ate undercooked pig can get what and is fought by what
trichinella and can be fought be eosinophils
eosinophils are also released in
allergic reactions occur, such as in the
peribronchial tissues of the lungs in people with asthma
and in the skin after allergic skin reactions. This action is
caused at least partly by the fact that many mast cells and
basophils participate in allergic reactions, as discussed in
the next paragraph. The mast cells and basophils release
an eosinophil chemotactic factor that causes eosinophils
to migrate toward the inflamed allergic tissue. The eosinophils are believed to detoxify some of the inflammation inducing substances released by the mast cells and
basophils and probably also phagocytize and destroy
allergen-antibody complexes, thus preventing excess
spread of the local inflammatory process.
heparin prevents
coagulation
basophil
The mast cells and basophils play an important role in some types of allergic reactions because the type of antibody that causes allergic reactions, the immunoglobulin E (IgE) type, has a special propensity to become attached to mast cells and basophils. Then, when the
specific antigen for the specific IgE antibody subsequently reacts with the antibody, the resulting attachment of antigen to antibody causes the mast cell or
basophil to rupture and release large quantities of histamine, bradykinin, serotonin, heparin, slow-reacting substance of anaphylaxis (a mixture of three leukotrienes), and a number of lysosomal enzymes. These substances
cause local vascular and tissue reactions that cause many, if not most, of the allergic manifestation
what is leukopenia
bone marrow produces less amount of wbc in the body
within 2 days when bone marrow stops producing wbcs
ulcers appear in mouth and colon or severe respiratory tract infection.
1 week after acute total leukopenia
a person can die
what can cause leukopenia ?
Irradiation of the body by x-rays or gamma rays, or exposure to drugs and chemicals that contain benzene or anthracene nuclei, is likely to cause aplasia of the bone marrow. Indeed, some common drugs such as chloramphenicol (an antibiotic), thiouracil (used to treat thyrotoxicosis), and even various barbiturate hypnotics on rare
occasions cause leukopenia
what is leukemia
Uncontrolled production of WBCs can be caused by cancerous mutation of a myelogenous or lymphogenous cell.
This process causes leukemia, which is usually characterized by greatly increased numbers of abnormal WBCs in the circulating blood.
2 types of leukemia
lymphocytic leukemia
and myelogenous leukemia
effects of luekemia on body
metastatic growth of leukemic cells in abnormal areas of the body. leukemic cells in bone marrow reproduce so much that they spread in surrounding tissues and may even cause bones to fracture and pan
anemia and excessive bleeding due to thrombocytopenia
excessive use of metabolic substrates by the cancerous cells which weakens the body
