Blood and Hematopoeisis Flashcards
What is the total volume of blood?
6 L or p 7-8% total body weight
What are the functions of blood?
- Delivery of O2 to cells and removal of CO2 and waste
- transport of hormones and regulatory substances
- maintenance of homeostasis: buffer and coagulation/thermoregulation
- protective: transport of immune cells
What are the two major components of blood?
- Formed elements: RBCs, WBCs, platelets
2. Plasma: matrix
What are the different layers of centrifuged blood?
Top light layer: plasma (55%)
Bottom red layers: RBCs (45%)
Middle thin buffy layer: WBCs and platelets (< 1%)
___________ is the volume of packed RBCs in a sample of blood.
Hematocrit
_______ accounts for over 90% of plasma.
Water
__________ accounts for roughly 7-8% of plasma.
Plasma proteins (albumin, globulins, fibrinogen)
_________ accounts for a mere 1-2% of plasma.
Other solutes (electrolytes, etc.)
T/F: Erythrocytes contain a nucleus, but no other organelles.
FALSE.
No nucleus, and missing typical organelles
What is the major function of erythrocytes?
Bind and deliver O2 to tissues and bind CO2 to remove from tissue.
What is the diameter of a typical erythrocyte?
7.8 um
What is the lifespan of a typical erythrocyte?
120 days
_________ is a specialized protein involved in binding, transporting, and releasing O2 and CO2.
Hemoglobin
Hemoglobin contains four polypeptide chains of globin each containing a _______ group.
Heme
How many O2 molecules can one hemoglobin protein bind?
- Each heme group can begin one O2 molecule.
What are the two major groups of leukocytes?
- Polymorphonuclear Granulocytes - specific granules, multilobed nuclei
- Mononuclear Agranulocytes - no specific granules, rounded nuclei
The three prominent polymorphonuclear granules are…
- Neutrophils
- Eosinophils
- Basophils
The two most prominent mononuclear agranulocytes are…
- Lymphocytes
2. Monocytes
What are the most numerous leukocytes?
Neutrophils
What is the function of neutrophils?
Show up first to Neutralize the situation
First responders to infection, acute inflammation, phagocytosis of bacteria within tissues
What is a distinguishing characteristic of neutrophils?
Dark, multiloped nucleus
What is a distinguishing characteristic of Eosinophils?
Large cytoplasmic granules, light bilobed nucleus
What is the function of eosinophils?
Defense against worms, role in allergies (histamine), chronic inflammation
What is the least abundant leukocyte?
Basophils
What is a distinguishing characteristic of basophils?
Granules are so large and dark, often hard to see nucleus
What is the function of basophils?
Regulate response to parasites, role in allergies
What is a distinguishing characteristic of a lymphocyte?
Nucleus is very dark and takes up almost whole cell, often small rim of cytoplasm on the outside
What are the three major lymphocytes and their functions?
- T lymphocytes - adaptive; cell-mediated immunity
- B lymphocytes - adaptive; humoral immunity, produce antibodies
- NK cells - innate; kill virally infected and malignant cells
What is a distinguishing characteristic of monocytes?
Large, dark, kidney shaped nucleus with no granules
What is the function of monocytes?
Differentiate into macrophages in tissue -> phagcytic cells
What is the smallest leukocyte?
Lymphocyte
Which is the largest leukocyte?
Monocyte
Thrombocytes (platelets) are derived from large cells within the bone marrow called _____________.
Megakaryocytes
What is responsible for clot formation and repairing tears in vessel walls?
Thrombocytes
T/F: The Monophyletic Theory of hematopoiesis states that blood cells are derived from multiple stem cells.
FALSE.
All from hematopoietic stem cell (HSC)
_______ and _________ are the only cell types to come from the common lymphoid progenitor.
Lymphocytes and plasma
T/F: HSC is pluripotent while the CMP and CLP are multipotent.
True
T/F: The higher the potentiality of a stem or blast cell, the lower the mitotic rate of that cell.
True
There are 9 stages to erythropoiesis, what are the first four?
HSC -> CMP -> MEP -> ErP
Hematopoietic stem cell -> common myeloid progenitor -> megakaryocyte/erythrocyte progenitor -> erythrocyte-committed progenitor
What are the last five “blast” steps of erythropoeisis?
proerythroblast -> basophilic erythroblast -> polychromatiophilic erythroblast -> orthochromatic erythroblast (normoblast) -> polychromatophilic erythrocyte (reticulocyte)
What happens from the proerythroblast phase to the basophilic erythroblast phase?
Nucleus stays large but gets much darker along with ring of cytoplasm
What happens between the basophilic erythroblast phase and the polychromatophilic erythroblast phase?
Cytoplasm ring gets lighter, nucleus shrinks slightly and has much more contrast in color from cytoplasm. Nucleus has checkerboard appearance.
What happens between polychromatic erythroblast and orthochromatic erythroblast (normoblast)?
Nucleus shrinks considerably
What happens between orthochromatic erythroblast (normoblast) and polychromatophilic erythrocyte (reticulocyte)?
Nucleus disappears
As erythropoiesis takes place RNA ____________ and Hemoglobin ___________.
Decreases; increases
What are the three different processes involved in leukopoeisis?
- Granulopoiesis
- Monocytopoiesis
- Lymphopoiesis
In granulopoiesis, how does the neutrophil pathway differ from eosinophils and basophils?
Neutrophils have a band cell stage
What is the general outline of granulopoeisis?
HSC -> CMP -> progenitor -> Myeloblast -> promyelocyte -> myelocyte -> metamyelocyte -> mature cell
What is the cell that gives rise to platelets?
Megakaryocyte
What is a distinguishing characteristic of megakaryocytes?
Very large cell with complex multilobed nucleus
What other blood cell shares a similar lineage to megakaryocytes?
Erythrocytes. (Megakaryocyte/Erythrocyte progenitor)
Bone marrow consists of _________ and _________ ______.
Sinusoids; hematopoietic cords
How is bone marrow cellularity calculated?
100% - age.
Hematopoietic cells decrease with age and are replaced with adipocytes.
