BL - Blood Cell Types

blood marrow

by pluripotent stem cells

tetramer of globin chains (recall that normal adult hemoglobin is composed of two alpha and two beta globins).
Each globin chain surrounds a porphyrin group with an iron atom (ie the heme group- four of them per hemoglobin molecule). The iron atom is what actually binds the oxygen.
 A mature red cell full of hemoglobin can carry about 1x109 oxygen atoms

iron atom binds oxygen

lack of RBC

decreased production OR increased destruction

• low levels of enzymes or ions required for RBC synthesis (iron, folate, vitamin B12)
• low levels of a hepatic hormone called erythropoietin that stimulates RBC formation

• mutations in cytoskeletal elements of RBC that make them more fragile, leading to RBC breakup (hemolysis)
• defects in anaerobic pathway enzymes, or enzymes that exist to break down reactive oxygen species
• autoimmune disorders where the immune system sees the RBCs as antigens and destroys them
• hydrophobic point mutations in globin chains such that aggregates of hemoglobins form inside the cells and deform the cell structure (ie sickle-cell anemia)
• partial thalassemias in which insufficiency of one type of globin makes homotetramers (ie four beta-globins together), which are unstable and prone to hemolysis
• immune reactions in which cytokines produced by inflammation reactions shut down RBC production.

in short
-hemolysis
-defects in anaerobic enzymes
-autoimmune
-hydrophobic point mutations
-partial thalassemias
-cytokines from inflammation shut down RBC production

megakaryocytes

break off...
derived in bone marrow

no nucleus
hemostatic function

uses two stains, eosin and methlyene blue, to stain basic and acidic cellular elements.
o Uses eosin to stain basic cellular elements red.
• Eosin-staining elements: hemoglobin, cytoplasmic granules
o Uses methylene blue to stain acidic cellular elements blue.
• Methylene blue-staining elements: primarily nucleic acids (DNA/RNA)
o Generally, the nucleus in most cells are blue; cytoplasm is a mix.
o In red blood cells, lots of basic hemoglobin-- thus lots of red.

basic

Hg
cytoplasmic granules

acidic

DNA/RNA

blue

red

yes,

RBC no nucleus

neutrophils
eosinophils
basophils

immature neutrophils

phagocytic
have vacuoles and some granules

t, b and nk cells

nucleus size of RBC

fluctuates through childhood, stays in the vicinity of 4.5-11.0 after that.

what percent of WBCs are lymphocytes, granulocytes, monocytes.

best expressed as # cells/L

1.0-4.8 x 109/L

Absolute count fluctuates through childhood and adolescence: adult ref range is 0.2-0.9 x 109/L

Absolute basophil count: 0-0.2 x 109 cells/L

Absolute eosinophil count: 0-0.4 x 109 cells/L

• Absolute neutrophil count: 1.8-7.8 x 109 cells/L

o Reticulocytes: immature RBCs in the peripheral blood which still retain organelles (ribosomes, Golgi apparatus, etc).
o After a day or two in the peripheral blood, these mature into RBCs-
o Can stain the peripheral smear to highlight residual organelles- you can then make an easy count from that.
o Stain essentially checks to see if your bone marrow is working properly-- an elevated reticulocyte count in the face of anemia means that the marrow is trying to compensate for the low RBC levels (thus anemia is due to RBCs being destroyed). If it's low, then there's likely a problem in the synthesis process of new RBCs.
o 1-2% of blood cells in a normal adult are reticulocytes to keep a constant RBC level.

women 4.2-5.4 (cells/microliter)
men 4.6-6.2

increases numbers of RBC

o Platelet count: 150,000-400,000 cells per microliter.
o Count does not fluctuate with age.
o Platelet "granules"-- contain substances that play a role in the initiation of the coagulation cascade.

condition in which a patient has too many red cells (generally neoplastic or cancerous)

condition in which a patient has too many red cells (generally benign)

too few platelets

too many platelets.

neoplastic condition in which there are too many platelets.

abnormal neoplastic proliferation of granulocytes and monocytes

abnormal neoplastic proliferation of lymphocytes.

too few neutrophils

too many neutrophils

too many eosinophils

too many basophils

too few monocytes

too many monocytes (tuberculosis or neoplastic problems)

too few lymphocytes (can be caused by corticosteroids)

too many lymphocytes (neoplastic causes, mainly)