Download red bone marrow

Translated from Russian to English - www.onlinedoctranslator.com
 Redbone
marrow (BMC)•
 Thymus Erythrocytes, platelets,
granulocytes, B-lymphocytes and
precursors of T-lymphocytes are
formed in the RMC Thymus is the
central organT-lymphopoiesis
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ContainsSKK and differentials hematopoietic cells
erythroid,granulocyticand megakaryocytic series,
as well as precursors of B- and T-lymphocytes.
Stroma bone marrow is reticular connective
tissue (microenvironment for hematopoiesis).
Elements of the microenvironment also include
osteogenic, fatty, adventitial, endothelial cells
and macrophages
 Perform
mechanical function,
secrete components of the main
substance precollagen,glycosaminoglycans,p
roelastin And microfibrillar
protein and are involved in the
creation of hematopoietic
microenvironment
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Called stem cells of supporting tissues,
osteoblasts and their
precursors.Osteogenic cells are part of
end osta and may be located in the bone
marrow cavities. Osteogenic cells are
also capable of producing growth
factors, inducing ancestral hematopoietic
cells in their locations to proliferation
and differentiation.
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(fat cells) are permanent elements of the
bone marrow.
Adventitial cells accompany blood vessels and
cover more than 50% of the outer surface
sinusoidal capillaries. Influenced
hemopoietins (erythropoietin) and other
factors, they are able to contract, which
promotes the migration of cells into the
bloodstream.
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Vessels bone marrow take part in the
organization of the stroma and
hematopoietic processes, synthesize
type IV collagen,hematopoietins.
Endotheliocytes, forming walls sinusoidal
capillaries, are in direct contact with
hematopoietic and stromal cells due to a
discontinuous basement membrane.
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Richly so somes and
phagosomes.Macrophages with the
help of their processes, penetrating
through the walls of the sinuses, they
capture an iron-containing compound
from the blood stream (transferrin)
and then pass it on to develop in
gerythroid cells for building heminova
parts of hemoglobin.
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are located in close contact with the
sinuses so that the peripheral part of
their cytoplasm penetrates into the
lumen of the vessel through the pores.
The separation of cytoplasmic
fragments in the form of platelets
(blood platelets) occurs directly into
the bloodstream.
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OutsideThe gland is covered with a
connective tissue capsule; septa extend
inward from it, dividing the gland into
lobules. In each lobule there
arecorticalAndcerebralsubstance. The basis
(stroma) of the organ is epithelial tissue,
consisting ofprocesscells –
epithelioreticulocytes(make up a whole
network, clinging to each other with shoots)
 In
addition to epithelial cells,
there are supporting cells
(macrophages and dendritic cells).
They contain products of the main
complex histo compatibility,
secrete growth factors (dendritic
cells) that influence the
differentiation of T-lymphocytes.
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More dark, since the peripheral part of
the thymus lobules contains large
numbers of T lymphocytes. IN
subcapsular the cortical zone contains
large lymphoid cells -T
lymphoblasts(4-5%), migrated here
from the bone marrow.
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Thisconversion of T lymphocyte precursors to
Tlymphoblasts.
Proliferation - this is reproductionTlymphoblaststhrough mitosis.
Antigen-independent differentiation- this is
differentiation with a small amountantigens. IN
This barrier consists of 5 components:
1) capillary endothelium;
2) their basement membrane;
3)pericapillarya fluid-filled space where
macrophages and lymphocytes are located;
4) basement membrane of the epithelial stroma;
5) cells of the epithelial stroma
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It has lighter color, because Compared to
the cortex, it contains fewer lymphocytes.
Lymphocytes in this zone are recycling pool
(a large group of cells that, after circulating
in the blood, can return to the medulla) of T
lymphocytes and can enter and exit the
blood stream through post-capillary
venules.
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Quantity mitotically
There are approximately 15 times fewer
dividing cells in the medulla than in the
cortex. In the middle part of the medulla
there are layered epithelial taurus-taurus
Hassalya. They are formed by
concentrically layer reticulocytes, the
cytoplasm of which contains large
vacuoles, keratin granules and bundles
of fibrils. The number of these bodies in
humans increases with age.
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Thymus reaches maximum development in early
childhood. In the period from 3 to 18 years,
stabilization of its mass is noted. At a later time,
reverse development of the thymus occurs. This
is accompanied by a decrease in the number of
lymphocytes, especially in the cortex, the
appearance of lipid inclusions in connective
tissue cells and the development of adipose
tissue. Layered epithelial bodies persist much
longer. In rare cases, the thymus does not
undergo age-related involution. This is usually
accompanied by a
deficiencyglucocorticosteroidsadrenal cortex.
Such people are characterized by reduced
resistance to infections and intoxications. The
risk of developing tumors especially increases.
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This temporary hypotrophy of the thymus
under the influence of unfavorable factors
(stress, starvation, infection, etc.). The
thymus is involved instress reactionsalong
with the adrenal glands. An increase in the
amount of adrenal cortex hormones in the
body, primarily glucocorticosteroids, causes
very fast and strong accidental involution of
the thymus. After the cessation of adverse
factors, restoration of the thymus occurs due
tosubcapsular zones.
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Are developingfrom
mesenchyme (8-10
weeks of
embryogenesis).
Are locatedalong the
lymphatic vessels.
Haveround or beanshaped.
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1)protective(barrier) – lymph, flowing through the
node, is cleansed by macrophages;
2)hematopoietic–lymphocytopoiesis when the
antigen enters the lymph.
3)immunobiological- pulpy cords B-lymphocytes,
strongly activated by antigen and T-lymphocytes,
turn 80% into plasma cells that produce
antibodies,
4)depositing- lymph depot. flowing
throughlymph nodes, lymph is cleared of foreign
particles and antigens by 95-99%, from excess
water, proteins, fats, and is enriched with
antibodies and lymphocytes.
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Lymph nodes are covered with a connective
tissue capsule, from which trabeculae extend
deeper. On the concave surface of the node there
is a gate (an artery, nerves enter, veins exit, and
an efferent lymph vessel). Bringers lymph vessels
enter from the opposite convex side. The stroma
of the nodes is represented by reticular tissue - a
network of reticular cells, collagen and reticular
fibers, as well as macrophages andantigenpresenting cells. The parenchyma of the nodes is
represented by lymphoid cells. Occurs in the
lymph nodes antigen-dependent proliferation
and differentiation of T and B lymphocytes
intoeffector(active) cells, as well as the formation
of T- and B-memory cells.
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Big part of the cortical layer and medullary cords are
made up of B-lymphocytes (B-zone), and
paracortical- the thymus-dependent zone contains
mostly T-lymphocytes (T-zone). In the center of the
lymph nodes there is a light center (germinative
(because they multiplyB lymphoblasts) and reactive
(because a reaction occurs between macrophages and
antigens). Where do B lymphocytes come from to the
cortical zone? They come here from the bone marrow
through the bloodstream. And then in lymph node
they are exposed to antigens phagocytosed
macrophages or retained by dendritic cells (see
below) and lymphakines,allocatedT-helpers. Under
the influence of all these influences, B lymphocytes
blast transformation, proliferation and antigendependent differentiation
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T-zone IN paracortical zone where T
cells proliferate and differentiate into
effector cells (killer cells, helper
cells,suppressors). Post-capillary
venules paracortical zones are the site
of penetration of circulating T- and Blymphocytes into the lymph node
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B-zone From nodules and paracortical zones
inside the l/node, into its medulla, the brain
cords extend,anastomosing between
themselves. It is based on reticular tissue, in
the loops of which there are Blymphocytes,plasma cells and macrophages.
This is where maturation happens.plasma
cells. Inside the medullary cords there are
blood vessels and capillaries containing pores
in the endothelium. The outside of the cords
are cover edendothelial-like reticular cells
lying on bundles of reticular fibrils and
forming the wall of the sinuses.
Spaces, limited by capsuleand trabeculaeon the one
hand, and nodules and medullary cords, on the other,
are called sinuses, which are, as it were, a
continuation of the afferent lymphatic vessels.
Distinguish
 1-subcapsular(marginal sinus), located between the
capsule and nodules,
 2-perinodular sinuses passing between the nodules
and trabeculae,
 3-brain sinuses bounded by trabeculae and
medullarycords
 4-gate sinus, which is located in the region of the
hilum of the lymph node.
Sinuses act as protective filters