Flashcards in Module 1: Heme: Intro slides 1-2 Deck (33):
First lets start off with the basics of heme (probably wont get tested, but good to know): What do myeloid stem cells produce?
Myeloid Stem cells:
1. Myeloblasts --- basophils , eosinophils and neutrophils
2. Immature Monocyte: Monocyte
3. Megakaryocyte: Platelets (megokaryocyte breaks off into little pieces and hence how you get platelets)
4. Pronormoblasts: Erythrocytes
What do lymphoid stem cells produce?
Lymphocytes which produce B and T cells
In regards to Pronormoblast, what is a sign of maturity?
Dissolving of the nucleus
Cytoplasm goes from basophilic to eosinophilic
At what point in the pronormoblast linage does the nucleus dissolve?
Polychromatic Erythrocyte ----- Reticulocyte ----- Erythrocyte
---at this point the cytoplasm is very pink due to proteins and eosinophilic
What is the morphology of a monocyte?
Kidney bean shaped
What is the morphology of neutrophil?
One of the granulocytes usually has 3-5 lobes (normally segmented)
---however if you see more than 5 lobes then this is hypersegmented
The precursor of a neutrophil is a band cell, explain the morphology of this and the importance of band cells?
Morphology: horseshoe nucleus
More band cells in peripheral blood then this is called a left shift (or bandemia) -- happens with severe bacterial infections
(should not have any band cells in the blood, so if you do this means that for some reasons the band cells are getting out into the peripheral blood before they can make neutrophils)
What is the morphology of an eosinophil?
Bilobed and filled with granules
What is the morphology of a basophil?
Basophilic with purple granules
Slide 1b: shows a peripheral blood smear or blood film, what is the stain for a blood smear?
Describe the morphology seen in slide 1b?
Top left: Band cell --- horseshoe nucleus
Top right: Eosinophils (bilobed)
Below and to the left of the eosinophil: neutrophils (3 lobes seen)
Below and to the right of the eosinophil: basophilic (super granulated)
Middle of slide: lymphocyte (no granules and big nucleus)
Bottom left: Monocyte (kidney bean)
RBC should be the same size as the nucleus of a lymphocytes (called normal cidic), how do you tell if they are the same size?
measure the MCV (mean cell volume)
What does microcidic mean?
Low MCV: small red blood cells (nucleus of lymphocyte is much bigger)
What does macrocidic mean?
Higher MCV: large red blood cells (nucleus of red blood cell is much bigger)
In a normal peripheral blood smear the zone of central pallor is about 1/3rd the size of RBC. How do you measure this?
if there is exaggerated normal pallor then the MCHC goes down and this is called hypochromic
(aka reduced hemoglobin in the cell so you see more of the biconcave disc) (pale RBC)
What happens if you see no central pallor?
Spherocytes and increased MCHC
(Ex. hereditary spherocytosis and sickle cell anemia)
(aka no biconcave disc due to a shit ton of hemoglobin in the cell and therefore cell is darker)
Normal RBC life cycle is stimulated by what??
The average RBC circulates for how many days?
120 days before getting destroyed via the spleen
Hb (Hemoglobin) is the main protein in RBCs, what is the function of hemoglobin?
Avid binding of O2 at high O2 tension- in lung
Release of O2 readily at low O2 tension - in tissue
Main transporter of CO2 from tissues - in lung
What is the general hemoglobin structure?
4 globin chains: 2 alpha chains and 2 other chains
--each globin is bound to a heme molecule containing iron
---in fetus: HbF is major Hb
---in adults: HbA (95%) and HbA2 (2%) and small HbF
RBCs are biconcave discs with large surface areas for Hb-O2 interaction which enables what?
Max O2 Saturation of Hb
Biconvcave shape also enables RBCs deformability for passage through what?
Small capillaries and splenic sinuses
Slide 1C to the left shows a normal histology or biopsy of the bone marrow, describe the morphology
Bone marrow: spongy portion inside bones
--meshwork of bone trabeculae (large arrow)
---contains hematopoietic marrow elements and fat cells
--ratio of hematopoietic elements vs fat depends on age and activity of marrow in response to physiologic stimuli
--normal ratio is 1:1 or 50:50
When there are reduced hematopoietic cells this is called hypocellular, what diseases cause this?
Aplastic anemia, Parvo virus, old age (Thats why old ppl are immune suppressed)
When there are increased hematopoietic cells this is called hypercellular, what diseases cause this?
Leukemia, polycythemia and hemolytic anemia (bone marrow makes more normoblasts to compensate for the damage of RBC)
Slide 1C to the right shows a cytology or aspirate on a Wright-Giemsa Stain, explain the morphology seen?
Myeloid to erythroid ratio: 3:1
--presence of megakaryotcytes, erythroid precursors, and granulocytic precursors
What part of the body is the most hematopoietically active in children?
Sternum (Red marrow)
What part of the body is most hematopoietically active in adults?
iliac crest or anterior superior iliac spine (yellow marrow -- this is safer for adults)
In slide two pic to the left shows basophilic stippling, what is included in basophilic stippling and what conditions is it seen in?
--seen in thalassemias, anemia of chronic diseases, iron deficiency (Sideroplastic anemia) and lead poisoning
In slide two the right pic shows Howell Jolly Bodies, what are these bodies?
DNA remnants in blood cells (they should not normally be in a blood smear)
--on blood smear your looking at a tiny little condensed nucleus
If a patient has their spleen taken out then they will have Howell Jolly bodies in their peripheral blood smear, in what conditions do patients get their spleen taken out?
Any kind of trauma
Sickle cell (fibrosis of the spleen)
Beta Thalassemia Major
--note all three of these are your chronic hemolytic anemia
why is the spleen taken out in the chronic hemolytic anemia diseases?
Rememeber that RBC are destroyed in the spleen
---in these patients the spleen is working overtime doing hemolysis and so therefore the spleen eventually becomes dysfunctional and fibrotic and shrinks