PART 1- THIRD LEARNING (Leukocytes, Bone marrow and Hematopoietic Neoplasia) Flashcards
Both the red blood cells and leukocytes present in the circulation are produced largely in the
bone marrow
They are theorized to arise from a common stem cell —
which under a series of differentiation produces the red cells and leukocytes.
(the pluripotential hematopoietic stem cell)
three compartments of leukocytes in the animal body:
- Circulating pool
- Marginal pool
- Marrow pool
comprises the leukocytes carried in the circulation
- Circulating pool
comprises the leukocyte that are present at the periphery of blood vessels;
- Marginal pool
- those leukocytes which are at the bone marrow awaiting differentiation and release, including those at other lymphoid tissues such as the lymph nodes and spleen.
- Marrow pool
Following infections, some leukocytes at the marginal pool and circulating pool are deployed to the site of infection (following
chemotaxis during inflammation
This egress of leukocytes towards the tissue is a —-
such that those deployed do not re-enter the circulation.
“one-way traffic”
Mechanism of neutrophilia
1.Normal distribution in bone marrow into tissue
Causes:
normal
mechanism of neutrophilia
2. Demargination of neutrophils.
causes:
Exercise
epinephrine
glucocorticoids
Mechanism of neutrophilia
4. increased releases of marrow storage pool cells
Causes:
Endotoxemia
Acute inflammation
Hypoxia
Glucocorticoids
mechanism of neutrophilia
3. Decreased extravasation into tissue
causes:
Glucocorticoids
Luekocytes adhesion deficiency
Mechanism of neutrophilia:
5. Expansion of marrow precursor pool
causes:
Chronic inflammation
Tumors
Rebound from neutropenia
Myeloproliferative disorder
are produced in the bone marrow, released into the peripheral blood and migrate into the tissues.
A. Granulocytes
- correspond to a general increase in the number of leukocytes in the circulation, irrespective of the leukocyte cell type involved (usually elevated neutrophil counts),
Leukocytosis
is the reverse or the general reduction in leukocyte numbers.
Leukopenia
normally progresses in the bone marrow in an orderly fashion from blast cell to mature granulocyte.
Granulopoiesis
. Major features of the hematopoietic system include the following:
(1) Proliferation of myeloid and lymphoid cells classically occurs in marrow and other lymphoid tissues, respectively.
(2) Seven nonlymphoid cell types and three major types of lymphoid cells are produced by the system.
can maintain itself against continual removal of cells into the differential proliferation pool; reconstitute itself if depletion occurs; and depending upon the demand, can increase cell production.
Stem cell pool
CFU-GEMM
colony- forming unit–granulocyte, erythrocyte, monocyte, megakaryocyte.
is not self-sustaining; made up myeloblast, pro granulocytes, and large and small myelocytes, and large and small myelocytes (the larger cells form a dividing pool that supplies cells to the maturation pool).
Differential proliferating pool
pool it is not self-sustaining; made up of metamylocyte, band cells, and mature segmented granulocytes; no DNA synthesis occurs her
Non-proliferating or maturation pool
o In the peripheral blood, granulocyte may be found adhering to the walls of
-small blood vessels
-making up the marginal granulocyte pool (MGP) or
-they may be found within the blood stream (circulating granulocyte pool or CGP) FMGP and
- CGP together make up the total blood granulocyte pool (TBGP).
o Proliferation of granulocytes is controlled by —
which are produced by —
(colony stimulating activity) hormones
monocyte-macrophages and activated T lymphocytes.
- phagocytosis of small particles
- neutrophils
e.g. neutrophils
pyogenic bacteria