Blood and Hematopoiesis Flashcards
What is the total volume of blood in the human body? (liters and percent body weight)
6L or 7-8%
What are the 5 main functions of blood?
- Delivery of O2 and nutrients to cells
- Transport of wastes and CO2 from cells
- Transport of hormones and other regulatory substances
- Maintenance of homeostasis by acting as buffer and participating in coagulation and thermoregulation
- Protective role via transport of immune cells and immune components
All formed elements of blood arise from what?
All arise from a hematopoietic stem cell
What are the two main cells in blood?
RBC (erythrocytes) and WBC (leukocytes)
What are cell fragments found in blood?
Thrombocytes (platelets)
What is the plasma of the blood?
Protein rich, fluid extracellular matrix
Define hematocrit.
Volume of packed RBC in a sample of blood
What are the three layers of blood after centrifugation?
Plasma, buffy coat, and erythrocytes
What is the relative volume of RBC in blood?
45%
What is the relative volume of the buffy coat?
1%
What is the relative volume of plasma?
55%
What is a normal male hematocrit value?
39-50%
What is a normal female hematocrit value?
35-45%
What are the three main components and percent distributions of plasma?
Water (92%), Proteins (7%), and other solutes (1%)
What are the three main plasma proteins?
Albumin, globulins, and firbrinogen
What are the “other solutes” found in plasma?
Electrolytes, non-protein nitrogen substances (i.e., waste materials), nutrients, blood gases, regulatory substances
Albumin makes up about how much of the volume of all three plasma proteins found in plasma?
50%
Where is albumin made?
Liver
What are the two main functions of albumin?
- Exerts concentration gradient; helps maintain osmotic pressure
- Acts as carrier protein, for substances such as hormones, metabolites, and drugs
What are the two kinds of globulins found in plasma?
Immunoglobulins (gamma-globulins) and nonimune globulins (alpha- and beta-globulins)
What are gamma globulins of blood plasma?
Antibodies secreted by plasma cells
Nonimmune globulins are produced where?
The liver
What do nonimmune globulins in plasma do?
Help maintain osmotic pressure and serve as carrier proteins
What is the function of fibrinogen?
Via series of cascade reactions, transformed into insoluble protein fibrin which helps form blot clots
What is serum?
The same thing as blood plasma, but the clotting factors have been removed
What is a blood smear?
Drop of blood placed directly on slide and spread thinly over surface with edge of another slide
What is blood stained with?
Wright’s stain
What is Wright’s stain?
Mixture of methylene blue (basic), azures (basic), and eosin (acidic)
What is the main function of RBC?
Bind and deliver O2 (99%) to tissues and bind CO2 (30%) to remove from tissues
What are the dimensions of RBC?
Diameter of 7.8μm, edge thickness of 2.6 μm, and central thickness of 0.8 μm
Why are RBC shaped the way they are?
This shape maximizes surface area that is important in gas exchange
Why are RBC sometimes called the “histologic ruler?”
Because they have a relatively constant shape and diameter in fixed tissue of 7-8 micrometers in diameter
Production of RBCs occurs where?
Red bone marrow via erythropoiesis
What is the life span of a RBC?
120 days
What is the rate of release of RBC?
2 million/second
What is hemoglobin?
Specialized protein involved in binding, transporting, and releasing O2 and CO2
What is the structure of hemoglobin?
- Four polypeptide chains of globin (α, β, δ, γ)
- Four iron-containing heme groups
Iron in heme binds how many O2 molecules?
One
How many oxygen molecules can be bound in one hemoglobin molecule?
Four
The most common type of hemoglobin is made up of what polypeptide chains?
Two α and two β chains
Leukocytes are subclassified into two general groups based on what?
Based upon presence or absence of prominent SPECIFIC GRANULES within cytoplasm and the SHAPE OF THEIR NUCLEI
What are the two subclassifications of leukocytes?
Polymorphonuclear granulocytes and mononuclear agranulocytes
What are the main features of polymorphonuclear granulocytes?
Contain specific granules and have multilobed nuclei; also possess azurophilic granules
What are the three polymorphonuclear granulocytes?
Neutrophils, eosinophils, and basophils
What are the main features of mononuclear agranulocytes?
No specific granules and have rounded nuclei; do contain azurophilic granules
What are the two mononuclear agranulocytes?
Lymphocytes and monocytes
What are the three lymphocytes?
B and T lymphocytes and natural killer (NK) cells
What percent of leukocytes are neutrophils?
49-67%
What is the diameter of a neutrophil?
12-15 micrometer
What does the cytoplasm look like in neutrophils?
Small faint lavender granules
What do the granules in the cytoplasm of neutrophils contain?
Lysozyme (specific granules) and perozidases (azurophilic granules)
What does the nucleus of a neutrophil look like?
Darkish; several lobes (2-5)
What are the three functions of neutrophils?
- First responders to infection
- Acute inflammation
- Phagocytose bacteria within tissues; accumulate as pus
Eosinophils comprise what percent of leukocytes?
1-5%
What is the diameter of an eosinophil?
12-15 micrometers
What does the cytoplasm of an eosinophil look like?
Large coarse acidophilic granules
What are the contents of the granules in eosinophils?
Peroxidase, histaminase,
arylsulfatase
What does the nucleus of an eosinophil look like?
Light, bilobed
What is the function of an eosinophil?
- Contribute to defense of parasitic infections (major role in defense against helminths
(worms) ) - Associated with allergies; release of histaminase & arylsulfatase moderates potentially harmful effects of inflammatory vasoactive mediators
- Chronic Inflammation
What is the percent abundance of a basophil?
0.0-0.3%
What is the diameter of a basophil?
12-15 micrometer
What is contained in the cytoplasm of a basophil?
Large coarse basophilic granules
What make up the granules of a basophil?
Histamine, serotonin, heparin sulfate
What does the nucleus of a basophil look like?
Light and bilobed; may be difficult to see
What is the function of a basophil?
-Involved in regulating immune response
to parasites
-Role in allergies via release of vasoactive agents (e.g. histamine)
Lymphocytes comprise what percent of leukocytes?
26-28%
What is the diameter of a lymphocyte?
6-18 micrometers
What does the cytoplasm of a lymphocyte look like?
Narrow rim of blue cytoplasm
What does the nucleus of a lymphocyte look like?
Very dark, takes up all of the cell,
round, slightly indented (can be somewhat triangular in shape)
T lymphocytes are involved in what kind of immunity?
Adaptive immune cells; cell-mediated immunity
B lymphocytes are involved in what kind of immunity?
Adaptive immune cells; humoral immunity
T lymphocytes mature where?
In the thymus
B lymphocytes produce what?
Antibodies
NK cells are involved in what kind of immunity?
Innate immune cells
NK cells attack and kill what?
Kill virally infected and malignant cells
Monocytes are what percent of leukocytes?
3-9%
What is the diameter of a monocyte?
12-20 micrometers
What does the cytoplasm of a monocyte look like?
Grey “foamy” texture
What does the nucleus of a monocyte look like?
Darkish; large, off-center; oval,
kidney, or horseshoe shaped
What does a monocyte differentiate into?
Macrophage
What is the function of a terminally differentiated monocyte?
As macrophages, serve as phagocytic cells involved in antigen presentation
Of the leukocytes which are the granulocytes?
Neutrophil, eosinophil, and basophil
Of the leukocytes which are agranulocytes?
Lymphocytes and monocytes
Thrombocytes are derived from large cells within the bone marrow called what?
Megakaryocytes
What is the size of a platelet?
2-3 micrometer
What is the lifespan of a platelet?
~10 days
What is the function of platelets?
Blood clot formation and repair of tears in blood vessel walls
What is the term for process of blood cell production and maturation?
Hematopoiesis
What are the names of the the processes that create the three formed elements in blood?
Erythropoiesis, leukopoiesis, and thrombopoiesis
Hematopoiesis takes place in what three embryonic phases before birth?
Yolk sac phase, hepatic phase, and bone marrow phase
What is the pluripotent cell that gives rise to all formed elements of blood?
Hematopoietic stem cell
What is the monophyletic theory?
All blood cells are derived from a common pluripotential stem cell: hematopoietic stem cell (HSC), Capable not only of differentiating into all the blood cell lineages, but also capable of self-renewal
In the bone marrow, descendents of the HSC can differentiate into what 2 major colonies of mulitpotential progenitor cells?
1) Common Myeloid Progenitor (CMP)
2) Common Lymphoid Progenitor (CLP)
Common myeloid progenitor cells give rise to what cells?
Megakaryocyte/erythrocyte progenitor cell and granulocyte/monocyte progenitor cell
Megakaryocyte/erythrocyte progenitor cells give rise to what?
Megakaryocyte and erythrocyte progenitor cells
Granulocyte/monocyte progenitor cells give rise to what?
Neutrophil, basophil, eosinophil, and monocyte progenitor cells
Common Lymphoid Progenitor (CLP) cells give rise to what?
Pre-NK, Pre-T, and Pre-B cells
Progenitor cells give rise to what?
Precursor cells or blasts
What does HCS stand for?
Hematopoietic stem cell
What does CMP stand for?
Common myeloid progenitor cells
What does MEP stand for?
Megakaryocyte/Erythrocyte progenitor cell
What does ErP stand for?
Erythrocyte-Committed Progenitor
Starting with Proerythroblast state all the stages of erythropoiesis to a RBC.
Proerythroblast, basophilic erythroblast, polychromatophilic erythroblast, orthochromatic erythroblast, polychromatophilic erythrocyte (reticulocyte), RBC
Granulopoiesis gives rise to what?
Eosinophils, basophils, and neutrophils
Monocytopoiesis gives rise to what?
Monocytes
Lymphopoiesis gives rise to what?
B, T, and NK cells
The band cell is only present in what line of granulopoiesis?
Neutrophil morphologic maturation
What are the general stages of granulopoiesis?
Myeloblast, promyelocyte, myelocyte, metamyelocyte, (band cell*), mature cell
What is the ploidy number of a megakaryocyte?
64N
What is the diameter of a megakaryocyte?
50-70 micrometers
What is endomitosis?
Chromosomes replicate, but neither karyokinesis nor cytokinesis occurs
Megakaryocytes are located near _______(1) within bone marrow, and send off cytoplasmic extensions that break off as ________(2)
(1) sinusoids
(2) platelets
The foamy peripheral cytoplasmic appearance of a megakaryocyte represents what?
Area where segmentation of platelets is occurring
Bone marrow is located where?
Within medullary cavity and spaces of spongy bone
Bone marrow consists of what?
Sinusoids (sinusoidal capillaries) and hematopoietic cords
What are in hematopoietic cords?
Developing blood cells, megakaryocytes, macrophages, mast cells, adipocytes
What are adventitial cells?
Reticular cells that Send sheetlike extensions into hematopoietic cords that will provide support for developing blood cells; stimulate differentiation of progenitor cells
What happens to the number of hematopoitic cells as we age?
They decrease
