Hematology Flashcards
What is plasma made up of?
90% Water
Plasma proteins synthesized in the liver: albumin (oncotic pressure), globulins (alpha and beta transport lipids, gamma is immunoglobulin), clotting factors (fibrinogen)
Electrolytes, gases, nutrients, wastes, hormones
What is the function of blood?
Transport nutrients/waste, defense against microorganisms/injury, acid-base regulation
What is unique about the anatomy of a RBC?
No nucleus, disc-shaped, biconcavity (for diffusion), reversible deformity (for squeezing through tight spots)
What are granulocytes vs. agranulocytes?
They are leukocytes
Granulocytes (many nuclei): neutrophils, eosinophils, basophils, mast cells
Agranulocytes (mononuclear): lymphocytes (NK cells), monocytes, macrophages
What is unique about neutrophils?
They make up the majority of WBCs (55%), they are the first responders, they only live for 4 days
Who has more digestive vacuoles? Granulocytes vs. macrophages/monocytes vs. lymphocytes
Granulocytes have the most
Macrophages/monocytes have fewer, larger digestive vacuoles
Lymphocytes have NO digestive vacuoles
What is a thrombocyte? What is its function?
Platelet, it controls bleeding (it is in the coagulation cascade, when it is activated, it works with fibrin to form a clot)
How many platelets do we have? What is the lineage?
140,000-300,000 (reserves are in the spleen)
They break off from megakaryocytes
How long do WBC vs. RBC take to make?
WBC takes one week, RBC takes 4 months (lives for 120 days)
Lymphopoesis vs. hematopoesis?
Synthesis of WBC vs. RBC, making them more differentiated, then they have less potential
They both start as pleuripotent stem cells
What are the primary and secondary lymphoid organs?
Primary: thymus and bone marrow
Secondary: spleen, lymph nodes, tonsils, and Peyer’s patches
The spleen is made up of red pulp and white pulp: What is the difference between white and red splenic pulp?
White: contains lymphocytes and macrophages
Red: principal filtration site, mainly phagocytize dead RBCs
Where does hematopoiesis take place?
Bone Marrow! (Medullary/myeloid are other terms for bone marrow)
Liver/spleen during embryonic development
Extramedullary sites with diseases
Red vs. Yellow bone marrow?
Red- active, hematopoietic tissue
Yellow- inactive, adipose tissue
RBCs are destroyed in about 120 days, so hematopoiesis occurs at a rate to make up for this. What are 3 ways to upregulate (example: if hemorrhaging occurs)?
- Yellow to red bone marrow using erythropoietin
- increase rate of differentiation of daughter cells
- increase rate of proliferation of stem cells
Name a few multi-lineage growth factors, what does this mean?
SCF (stem cell factor)
GM-CSF (granulocyte-macrophage colony stim factor)
IL-6 (interleukin-6)
These growth factors are involved in more than one pathway
What are some lineage-specific cytokines, what does this mean?
M-CSF (macrophage colony stimulating factor)
EPO (erythropoietin)
TPO (thrombopoietin)
Growth factors that are only involved in one pathway
What is EPO a growth factor for?
Makes erythropoetic stem cells into erythrocytes
What is TPO a growth factor for?
Makes megakaryocytic stem cells into megakaryocytes which can break off (endocytosis) into platelets
What is M-CSF a growth factor for?
From monocytic stem cells to monocytes and macrophages
GM-CSF also does this
What is G-CSF a growth factor for?
It helps differentiate G-M stem cells to granulocytes, then granulocytes into neutrophils, basophils, and eosinophils
What happens during erythropoiesis with the nucleus and with hemoglobin?
From pleuripotential stem cell to erythrocyte, it loses its nucleus, during the process it starts making hemoglobin, by the time it becomes an erythrocyte, it stops making hemoglobin
How is hemoglobin synthesized?
Hemoglobin is synthesized by vitamin B12 and folic acid, if someone is deficient they will have anemia
What does Iron have to do with hemoglobin?
67% of iron is bound to hemoglobin
Note: 30% is stored (ferritin in liver), 3% lost, it is recycled when RBC dies in 120 days
How is iron cycled?
- Fe is released into erythroblast mitochondria, 2. it is used to make hemoglobin, 3. RBC circulates 120 days, 4. dead RBC removed from blood by macrophages, 5. Fe released back into blood or stored as ferritin/hemosiderin
What is endomitosis?
When the megakaryocyte is pinched off to form platelets, during mitosis it does not undergo cytokinesis (doesn’t split to 2 daughter cells)
What does aspirating bone marrow NOT tell you clinically? How is aspirating different from biopsy?
Aspirating can’t let you know the efficiency of activity (making RBCs), it is not diagnostic, aspirating tells you if there are certain cells present to give you an idea of what is going on but a biopsy is more specific and accurate
If you biopsy bone marrow and find fibrotic marrow, what does this mean?
There is injury/cell death happening, scar tissue is forming, multiple cell types will be reduced
What are some changes with aging regarding erythrocytes and lymphocytes?
Erythrocytes are replaced more slowly (Note: RBCs still live 120 days), less iron
Lymphocyte function is decreased, less T cell function, less humoral response, platelets become “sticky” (more likely to clot)
What happens in primary hemostasis?
- exposure to collagen, 2. platelets adhere (using glycoproteins)
- platelets are activated (release granule contents and go through conformation change), 4. aggregation, 5. form platelet plug
What happens in the intrinsic vs. extrinsic pathway and what do they yeild?
Intrinsic: in skeletal muscle and joints, factor 7, subendothelial substances exposed
Extrinsic: in brain, lung, and heart, tissue factor released by damaged endothelial cells
Together, they yield prothrombin
What happens in secondary hemostasis?
Coagulation cascade
How are thrombin, prothrombin, platelets, and fibrin involved in the coagulation cascade?
Prothrombin becomes activated to yield thrombin
Thrombin yields platelets and fibrin (fibrinogen -> fibrin), which together forms a clot
Fibrin is a sticky substance that traps RBCs
What is tertiary hemostasis?
Fibrinolysis, clot dissolution
What primarily activates the lysis of a clot?
Plasmin, activated by pasminogen
How are tPA, PAI, plasminogen, and plasmin all related in the lysis of blood clots?
tPA activates plasminogen into plasmin
PAI inhibits tPA, inhibiting the conversion of plasminogen into plasmin
What happens if PAI is overactive?
It inhibits the tPA (the activation of fibrinogen to fibrin), so in the end, clots aren’t getting broken down
When plasmin breaks up fibrinogen and fibrin, what are the products?
FDP (fibrin degradation products) and D-dimer
How are erythrocytes broken down?
- aged RBCs destroyed by macrophages, 2. broken down into heme and porphyrin, 3. porphyrin makes bilirubin, 4. bilirubin is excreted into urine/feces
How does the blood cell count differ between adults and newborns?
Newborns have MORE, they have 88 mL/kg, adults have 75 mL/kg
Newborns have more lymphocytes, but about the same number of platelets
What cells can be formed from GM-CSF?
Granulocytes and Agranulocytes (monocytes, macrophages)
Eosinophils vs. Basophils vs. Mast cells
Eosinophils ingest antigen-antibody complexes and are involved in the recovery phase of the inflammatory process
Basophils are vasoactive amines (histamine) and anticoagulants
Mast cells are involved in wound healing, also histamine, inflammation, and have rapid vessel permeability
