Aug. 21 Organization of Blood and Blood forming organs
What does mononuclear phagocytic system (also called the reticular endothelial system or RES) includes?
Circulating blood monocytes Fixed macrophages in the bone marrow, liver, spleen, and lymph nodes Free macrophages
Describe blood composure.
Composed of Fluid portion (plasma) and formed elements.
What does the marrow contain?
Contains both erythroid (RBC) and leukocyte (WBC) precursors as well as platelet precursors.
What does the thymus serve as?
A compartment for the maturation T cells.
When are Granulocytes formed?
About 5 month
What does the pathological state include?
Acute blood loss, severe chronic anemia, and malignant disease.
What is consider as physiological changes in normal values of the formed cellular elements.
Age, sex, and geographic location.
Discuss the liver.
Contains phagocytic cells known as kupffer cells that act as filter for damaged or aged cells, Similar and and less efficient than the phagocytic cells in the spleen .
What are the minor sites of blood production?
spleen, kidney, thymus, and lymph nodes
Define hematopoiesis
Term describing the formation and development of blood cells.
What happens in the bone marrow in a certain pathologic state?
The bone marrow can increase its activity to 5-10X its normal rate
Describe hematopoiesis in the fetus stages (2months)
The fetal liver assumes hematopoiesis and the yolk sac production of erythrocytes decreases.
Describe hematopoiesis in the later fetus stages (3-6months)
The fetal liver becomes the chief site of blood cell production. Splenic hematopoiesis also occurs. T
Describe hematopoiesis in a normal adult.
The proliferation, differentiation, and maturation of the hematopoietic cells (RBCs, WBCs, and platelets) is limited to the bone marrow and the widespread lymphatic system and only mature cells are released into the peripheral blood.
How does the body maintain hematopoiesis?
The system must have the capacity for self renewal
Describe hematopoiesis in terms of survival.
These cells are constantly being lost or destroyed.
Describe the function of a Erythrocytes (RBC)
They contain hemoglobin. They function in the transport of O2 and CO2
What is involved with cellular destruction?
mononuclear phagocytic system (also called the reticular endothelial system or RES)
Describe hematopoiesis in the early stages (19 days after fertilization)
Begins in the yolk sac of the embryo and only erythrocytes are made. The RBCs contains unique fetal hemoglobin.
Describe hematopoiesis in the later fetus stages (7months)
Blood cell production shifts to the developed bone marrow, which becomes the major site of blood cell development in the fetus.
What is filled with erythroid cells in fetus development?
Bones of the toes, fingers, vertebrae, ribs, pelvis, long bones and cranium
How are normal values for a group determined by?
By calculating the mean for healthy individuals of the group and reporting the nor,al ranges as the mean +/- 2 standard deviations.
How is hypersplenism relieved?
By splenectomy
List the lab test that measure deviation of the blood constituents.
CBC (Complete blood count) , RBC count, WBC count, platelet count, hemoglobin, hematocrit (packed cell volume), Mean corpuscular (MCV), Mean corpuscular hemoglobin concentration (MCHC)
Discuss pluripotential stem cells.
Can differentiate into all of the distinct cell lines with specific functions and they are able to regenerate themselves. Can provide the cellular reserve for the stem cells that are committed to a specific cell line.
Function of spleen.
Culling-Filtering and destruction of senescent (aged) or damaged RBCS Pitting-Removal of particles (are found in some types of anemia) from RBC membranes - -this causes a decrease in the surface to volume ratio of the RBC resulting in the formation of spherocytes
When are lymphocytes formed?
Early lymphocytes are formed and a few megakaryocytes first appear at 3 months of fetal life
What are free macrophages involved?
Engulfing particulate matter, Processing of antigens for lymphocyte presentation, and Removal of damaged or senescent (aged) cells
What are the formed elements of blood?
Erythrocytes (Red Blood Cells) Leukocytes (White Blood Cells) Thrombocytes (Platelets)
What leads to hepatomegaly and/or splenomegaly (increase in size of the liver and/or spleen because of increased functions in the organs).
Extramedullary hematopoiesis of an adult when the bone marrow cannot meet the physiologic needs of the tissues
What does variation in the formed elements in the blood tells us.
First sign that disease is occurring in the body. The changes caused by diseases may be detected by lab test that measure deviation of the blood constituents from normal values.
When does hyperplastic occurs?
In conditions where there is increased or ineffective hematopoiesis. When this condition occurs it is related to the severity and duration of the pathologic state.
Discuss the bone marrow in term if age.
In the early life most of the bone marrow is red marrow and it gradually decreases with age to the adult level of 50%
What can committed myeloid stem cells differentiate into?
Into any of the other hematopoietic cells including erythrocytes, neutrophils, eosinophils, basophils, monocytes, macrophages, and platelets.
Describe the function of a Thrombocytes (Platelets)
Involved in hemostasis which forms a barrier to limit blood loss at an injured site
What is committed lymphoid stem cells involved in?
Involved in lymphopoiesis to produce lymphocytes.
Describe the function of a Leukocytes (WBC)
Involved in the body's defense against the invasion of foreign antigens.
What type of tube is use to obtain specimen.
Lavender Top because it contains EDTA (AntiCoagulant)
What does enlarged spleen lead to?
Leads to peripheral thrombocytopenia, Which decrease in platelets store in the peripheral blood.
Discuss the mature blood cells life span.
Limited about 120 days. Replacement of peripheral hematopoietic cells is a function of the pluripotential stem cells found in the bone marrow.
Discuss bone marrow.
Located inside spongy bone. Normal adult 1/3 of the bone marrow is hematopoetically active (red marrow) and 1/2 is inactive )fatty marrow-yellow marrow)
List secondary lymphoid organs.
Lymph nodes and spleen
What is the important site for lymphopoiesis (production of lymphocytes) throughout life.
Lymph nodes,
What can hypersplenism cause?
May causes anemia, leulopenia, or thrombocytopenia (decreased platelets), or a combination of these cytopenias
What is consider as pathologic changes in values of the formed cellular elements.
Occur with disease or injury
Hematologic abnormalities in quantitative and/ or qualitative are the results of what?
Of an imbalance between cell production, release, and/or survival.
Discuss the thymus.
Organ is well developed at birth and increases in size until puberty at which time it starts to decrease in size.
Discuss lymph nodes.
Part of the Lymphatic system. Composed of lymphocytes, macrophages, and reticular network. Act as a filter to remove foreign particles by phagocytic cells
List and discuss hematopoietic cells division of cellular compartments.
Pluripotential stem cell: capable of self-renewal and differentiation into all blood cell lines. Committed proginator stem cells: destined to develop into distinct cell lines Mature cells: With specialized functions.
What are the two types of hypersplenism?
Primary hypersplenism and secondary hypersplenism.
What does the system of hematopoiesis involves?
Proliferation of progeny stem cells differentiation and maturation of the stem cells into the functional cellular elements
Describe a bone marrow that is normal, hyperplastic, and hypoplastic.
Reer to figure 1.4
Draw a graph hematopoiesis vs. months/ years
Refer Figure 1.3
What happens after an splenectomy?
Splenectomy is the removal of the spleen. RBC inclusions and abdmormal RBC shapes are seen. Culling is taken over by the liver which is less effective in performing all the splenic functions.
What is hematology?
Study of blood. Primarily a study of the formed cellular elements.
List primary lymphoid organs.
Thymus and bone marrow
What does hematopoietic tissues includes?
Tissues involved in the proliferation, maturation, and destruction of blood cells
Describe normal conditions of blood cells.
Under normal conditions the production, release, and survival of blood cells is highly regulated process.
What does alteration in the formed elements in the blood result to ?
Usually a result of disease rather than being the primary cause of disease.
What is in the plasma region?
Water, proteins and other solutes.
What is pancyopenia? (This occurs in hypersplenism)
When all three cell types are decreased.
What is hypoplastic?
When the hematopoietic tissue becomes inactive and it may be due to chemicals, genetics, and myeloproliferative disease that replaces hematopoietic tissues with fibrous tissue.
What is hypersplenism?
When the spleen becomes enlarged though an exaggeration of its normal functions of filtering, and destruction and sequestering.
What is in the buffy coat region?
White blood cells and platelets. White blood cells--> Lymphocytes, granulocytes, monocytes, basophils, neutrophils, and eosinophils.
Describe blood production when the bone marrow becomes the primary site of about 6 months of gestation and continues throughout life
blood production in the other areas decreases and finally ceases as the bone marrow becomes the primary site
Describe the spleen
contains (stores) the largest collection of lymphocytes and mononuclear phagocytes in the body
Define extramedullary hematopoiesis
hematopoiesis in areas other then the bone marrow. Extramedullary hematopoiesis may occur in fetal hematopoietic tissue (liver and spleen) of an adult when the bone marrow cannot meet the physiologic needs of the tissues.
Define medullary hematopoiesis
hematopoiesis in the bone marrow
What is the term used to describe the bone marrow when it increase its activity rate
hyperplastic because it replaces the yellow marrow with red marrow.
