Module 1: Heme: Intro slides 1-2

Question 1

First lets start off with the basics of heme (probably wont get tested, but good to know): What do myeloid stem cells produce?

Answer 1

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

Question 2

What do lymphoid stem cells produce?

Answer 2

Lymphocytes which produce B and T cells

Question 3

In regards to Pronormoblast, what is a sign of maturity?

Answer 3

Dissolving of the nucleus

Cytoplasm goes from basophilic to eosinophilic

Question 4

At what point in the pronormoblast linage does the nucleus dissolve?

Answer 4

Polychromatic Erythrocyte —– Reticulocyte —– Erythrocyte
—at this point the cytoplasm is very pink due to proteins and eosinophilic

Question 5

What is the morphology of a monocyte?

Answer 5

Kidney bean shaped

Question 6

What is the morphology of neutrophil?

Answer 6

One of the granulocytes usually has 3-5 lobes (normally segmented)
—however if you see more than 5 lobes then this is hypersegmented

Question 7

The precursor of a neutrophil is a band cell, explain the morphology of this and the importance of band cells?

Answer 7

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)

Question 8

What is the morphology of an eosinophil?

Answer 8

Bilobed and filled with granules

Question 9

What is the morphology of a basophil?

Answer 9

Basophilic with purple granules

Question 10

Slide 1b: shows a peripheral blood smear or blood film, what is the stain for a blood smear?

Answer 10

Giemsa Stain

Question 11

Describe the morphology seen in slide 1b?

Answer 11

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)

Question 12

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?

Answer 12

measure the MCV (mean cell volume)

Question 13

What does microcidic mean?

Answer 13

Low MCV: small red blood cells (nucleus of lymphocyte is much bigger)

Question 14

What does macrocidic mean?

Answer 14

Higher MCV: large red blood cells (nucleus of red blood cell is much bigger)

Question 15

In a normal peripheral blood smear the zone of central pallor is about 1/3rd the size of RBC. How do you measure this?

Answer 15

MCHC
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)

Question 16

What happens if you see no central pallor?

Answer 16

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)

Question 17

Normal RBC life cycle is stimulated by what??

Answer 17

Erythropoietin

Question 18

The average RBC circulates for how many days?

Answer 18

120 days before getting destroyed via the spleen

Question 19

Hb (Hemoglobin) is the main protein in RBCs, what is the function of hemoglobin?

Answer 19

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

Question 20

What is the general hemoglobin structure?

Answer 20

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

Question 21

RBCs are biconcave discs with large surface areas for Hb-O2 interaction which enables what?

Answer 21

Max O2 Saturation of Hb

Question 22

Biconvcave shape also enables RBCs deformability for passage through what?

Answer 22

Small capillaries and splenic sinuses

Question 23

Slide 1C to the left shows a normal histology or biopsy of the bone marrow, describe the morphology

Answer 23

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

Question 24

When there are reduced hematopoietic cells this is called hypocellular, what diseases cause this?

Answer 24

Aplastic anemia, Parvo virus, old age (Thats why old ppl are immune suppressed)

Question 25

When there are increased hematopoietic cells this is called hypercellular, what diseases cause this?

Answer 25

Leukemia, polycythemia and hemolytic anemia (bone marrow makes more normoblasts to compensate for the damage of RBC)

Question 26

Slide 1C to the right shows a cytology or aspirate on a Wright-Giemsa Stain, explain the morphology seen?

Answer 26

Myeloid to erythroid ratio: 3:1 | --presence of megakaryotcytes, erythroid precursors, and granulocytic precursors

Question 27

What part of the body is the most hematopoietically active in children?

Answer 27

Sternum (Red marrow)

Question 28

What part of the body is most hematopoietically active in adults?

Answer 28

iliac crest or anterior superior iliac spine (yellow marrow -- this is safer for adults)

Question 29

In slide two pic to the left shows basophilic stippling, what is included in basophilic stippling and what conditions is it seen in?

Answer 29

Ribosomal RNA | --seen in thalassemias, anemia of chronic diseases, iron deficiency (Sideroplastic anemia) and lead poisoning

Question 30

In slide two the right pic shows Howell Jolly Bodies, what are these bodies?

Answer 30

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

Question 31

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?

Answer 31

``` Any kind of trauma Sickle cell (fibrosis of the spleen) Hereditary Spherocytosis Beta Thalassemia Major --note all three of these are your chronic hemolytic anemia ```

Question 32

why is the spleen taken out in the chronic hemolytic anemia diseases?

Answer 32

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

Question 33

Patients with these Howell Jolly Bodies are susceptible to what types of infections?

Answer 33

Encapsulated bacterial infections because splenic macrophages normally opsonize these types of bacteria. ---including: Strep Pneumonia (lobar pneumonia), H. influenza ( COPD infections) and N. Meningitis (Adolescents)