20110124 06 connective cells notes

From Iusmhistology

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(Created page with '*started here on 01/24/11 at 2PM. ==Connective Cells== *Think about the CBC, we're trying to understand this better and know the entities a little better. ===Blood smear=== *W…')
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***Living at altitude
***Living at altitude
-
==Lab==
+
==Laboratory 7: Blood==
===Prep===
===Prep===
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**Look for RBCs with macrophages surrounding them.
**Look for RBCs with macrophages surrounding them.
**Look for sinusoidal units.
**Look for sinusoidal units.
 +
 +
===Peripheral blood===
 +
 +
====Slide 18 blood smear====
 +
*Wright stain was used on this blood stain.
 +
*RBC's ........................ pink.
 +
**Nuclei. ........... absent.
 +
*Neutrophils
 +
**granules ................ small, pink to light purple.
 +
**cytoplasm ............ .light pink.
 +
**nucleus ................. lobulated, blue or purple.
 +
*Eosinophils
 +
**granules ................. large, red to orange.
 +
**nucleus ................. .lobulated, blue or purple.
 +
*Basophils
 +
**granules ................. .large, dark blue to purple or black, often mask nucleus.
 +
*Lymphocytes
 +
**cytoplasm ............... light pink to deep blue, scant amount.
 +
**nucleus .................... round, deep blue or purple
 +
*Monocytes
 +
**cytoplasm .............. gray to blue.
 +
**nucleus ................. .less intense blue than lymphocyte, has open areas
 +
*Platelets .......................... purple.
 +
*A differential count is a count of 100 cells and then describing the percent of those 100 cells by their identities.
 +
**Look in a field and identify the first 100 cells you see.  Average the counts over four observations.
 +
**See Basic Histology, table 12-2 for standard ranges.
 +
 +
====Slide 99 colon====
 +
*locate regions of very loose connective tissue.  Look, also, for cells within blood vessels.
 +
*Neutrophils can be identified by their segmented nuclei.
 +
*Eosinophils stand out because they contain bright red granules.
 +
*Lymphocytes and plasma cells can be found in the loose connective tissue that lies beneath the colonic epithelium.
 +
 +
===BONE MARROW (MYELOID TISSUE)===
 +
 +
====Slide 21 bone marrow====
 +
*also, Slide 8 bone marrow smear
 +
*look for segments of thin-walled sinusoids.
 +
**Look closely, as apparent channels running along trabecular bone surfaces may be separation artifact; the result of shrinkage and separation of soft tissue from the bone.
 +
**The presence of RBC's can often help to identify sinusoids.
 +
**The sinusoids show up as large blank circles with endothelial cells lining them.
 +
**This makes sense because they are cross-sections.
 +
*Identify megakaryocytes within medullary cords (tissue between sinusoids).
 +
**These cells are large (~5X bigger than any surrounding cell).
 +
*Look also within the cords for the intense red granulation that identifies cells of the eosinophil developmental series.
 +
 +
 +
*Note: Slides 4 and 5 used in Lab 12 on bone formation contain sinusoids within fairly well-preserved regions of bone marrow.
 +
 +
 +
====Slide 8 (marrow smear)====
 +
*optional; however, this slide may be a good self-test of your understanding of blood cell  development.
 +
*identification of the various stages in erythrocyte and granulocyte development (considerable skill needed).
 +
*We ask that you understand the structural features (and functional correlates) that distinguish the various stages of erythropoiesis and granulopoiesis.
 +
*However, you are not required to identifY these cell stages in micrographs.
 +
 +
====Slide 18====
 +
*Optional exercise: It is not uncommon to find late stages in erythrocyte or granulocyte development in a peripheral blood smear. lf you feel you have time, try going back to slide 18 (peripheral blood) to see if you can fmd immature cell stages.
 +
*Polychromatophilic and orthochromatophilic erythroblasts
 +
**Look for cells that are about the same size as an erythrocyte, but that still contain a nucleus.
 +
*Neutrophilic band cells (stab cells) are relatively easy to find in slide 18.
 +
**A key feature of the band cell is its "band" shaped nucleus (can be U, horseshoe shaped).
 +
**Your text and the atlases each have good examples of these cell types.
*stopped here on 01/24/11 at 3PM.
*stopped here on 01/24/11 at 3PM.

Revision as of 20:42, 24 January 2011

  • started here on 01/24/11 at 2PM.


Contents

Connective Cells

  • Think about the CBC, we're trying to understand this better and know the entities a little better.

Blood smear

  • We want to understand what is normal so that we'll recognize abnormal next year.

NEJM review

  • Review talked about how many things could be diagnosed by blood smear.
  • "Diagnosis from the blood smear"

Hematopoiesis

  • How blood cells develop in the first half.
  • Second half = features of blood cells.
  • Hematopoiesis starts early in development.
  • Early on it is in the yolk sac, then the liver with a little spleen, then finally the bone marrow.

Hematopoiesis lineages

  • HSCs are our topic for today.
  • Pluripotent:
    • self renewing
    • can become other types of cells
  • Less than 0.01% of cells in the body are HSCs

Colonies

  • HSC derivatives develope in colonies: localized groups of certain types of cells.
  • These are developed by CSF (colony stimulating factors).
  • Read through the table; they are pretty intuitive.

Progenitors

  • Progenitors develop into the "blast" cells (precursors).
    • This is the first stage at which you can determine they are of a certain type.
  • Precursors are generally unipotent
    • Other than "myloblast"?

Marrow

  • Two types of marrow:
    • Red marrow: active hematopoiesis
    • Yellow marrow: fatty marrow filled with adipocytes; inactive in terms of cell production

Histo

  • Bone marrow will show some fat cells and some little hematopoieitic cells.
    • Some adipocytes doesn't mean it's yellow marrow.
  • Marrow turns red to yellow over time.

Red marrow

  • Has several structures.
  • Stroma
    • Where cells reside
    • Network of fibers: collagen, chicken wire
    • Cell nests sit within the network.
    • Reticular cells are found in the stroma
      • AKA adventitial cells, reticular fibroblasts, reciculocytes
      • Also found in lymph nodes
      • Specialize in mamking the reticular fibers
    • Fibronectin is found in the stroma
      • Holds colonies together
      • Dissolves when cells are ready to go into blood stream
  • Hematopoietic cords
    • site of blood cell formation, contains CFUs
    • ?
  • Sinusoidal capillaries
    • You should review material from vessel lecture
    • Blind ends

Yellow marrow

  • Mostly adipocytes
  • Inactive
  • Can revert to red marrow when we need more blood cells.
    • Severe blood loss
    • Localized portions revert
    • Chronic inflammation

Scanning EM

  • These are cords with sinusoidal caps (where cells enter circulation)


  • Now we'll tlaka bout each cell line.

Erythroblasts

  • made in erythroblast islands
    • like colonies
    • macrophage in the center which holds developoing erythrocytes around it
      • the macrophage's cytoplasm extends out and around the erythrocytes
  • Erythropoietin (made by kidney) stimulates macrophage
  • Macrophage stimulates erythroblasts to rpoduce hemoglobulin
  • We won't have to identify each stage of the erythroblast visually, but verbally, yes.

Stages

  • first
  • Second: el
    • Very basophillic cytoplasm b/c of many ribosomes (hb production)
  • Third
    • Looses some basophilic nature
    • Start to see hb accumulate
  • First three stages are all mitotic so they divide
    • At fourth, mitosis stops
  • Foruth: ortho...
  • Fourth to fift: nucleus ejected

Mature RBC

  • no nuc
  • no organelles
  • discoids
    • allows them to bend and get through caps
  • 7-8 microns: an histological ruler
  • Live for 120 days
  • Phagocytosed in spleen and a little in the bone marrow
  • As membrane breaks down, that's what dsignals destruction by macrophages.

RBC membrane

  • Spectrin and anchorin are key in discoid shape.
  • Well studied membrane because it's easy to get ahold of.
  • Not responsible for blood substitutes.

Leukocytes

  • Two categories: with or without granules
    • All leukocytes have granules (asurophilic granules)
  • Don't memorize what is in the granules, but know that all leukocytes have whats in the azurophilic granules.
  • Granulocytes have specific granules: nt, eosins, baosphils 
*

Granulocytes

  • Development in colonies
  • the progenitor in this case can develop into 3 different types
  • four stages:
    • myeloblast
      • GCSF causes it to become a ...
    • promyelocyte / promyeloblast
      • then can become one of three myelocytes
    • Myelocytes
      • First time we see specific granules
    • Metamyelocyte stage
      • Continue to accumulate specific granules, titrate them to concentration
Neuts
  • 60-70 % of leukocytes
  • Number of sengments of nucleus is indicative of cell's age.
  • Young neuts = band cells (horse-shoe shaped nuc)
  • In females we can see a small bar body (the inactivate X)
  • Once in connnective tissue, dead in 1-4 days.
  • Only activated once in circulation
  • Have p-selectin ligands for slowing and tumbling on endothelium.
  • Enter connective tissue via dapedesis
  • Kinetics:
    • Can be in several compartments
    • Medullary hold storage compartment in place
    • Look in notes for the four compartments.
Eosinophils
  • 2-4% of the
  • 2-5 nuclei sections
  • Highly eosinophillic granules (very pink)
  • Often a bilobed nucleus
  • Major protien is "major basic protein"
    • Helps kill parasites
Basophils
  • < 1% of leukocytes
  • Irregular nuc
    • Usually bilobed
    • Hard to sse because granules stain so well
  • Granules are hihgly basophilic
  • Proteins:
    • Heparin, histamine
    • mediate inflammation
    • Act much like mast cells

Agranulocytes

Monocytes
  • GMcsf genreates these
  • Go into circulation as monocyte
  • Go into tissue and become macrophages
    • Have different names in diff tissues
      • Glia in CNS
      • Review bidwell's slide on names given tissue
  • Oval shaped nucleus
    • or horseshoe or kdiney shaped
  • Nuc is usually ecentric
Lymphocyte
  • 28% of leukocytes
  • Come in small, medium, and large
    • Small ar emost prominent, have nearly no cytoplasm
  • More on B and T cells on wednesday
    • T cells in cell-mediated immunity
    • B cells ....
    • Can't tell the diff in our microscopy
Thrombocytes
  • Platelets come from megakaryocytes
  • No nuclei
  • They have two distinct regions, two membranes
  • There is an open system (an invagination of the membrane)
    • For nutrient uptake
  • Tubular system
    • Microfilaments that wrap around the cell
    • Release things from cells
  • Platelets are much smaller than RBCs; often clumnped.
blood clotting
  • Primary aggregation:
    • Platelets cling to injury on wall
  • Singaling with factors for more platelets
  • Secrete fibrin, build network
  • Traip other cells
  • Clot formed
  • Clot retracted
  • Healing
  • removal
Megakaryocytes
  • Very large
  • Lobulated nucleus
  • 6-7 times larger than RBC
  • Megakaryocyte puts processes out into the vessel: proplatelets.

Whole blood

  • Cells
  • Hematocrit: % of RBCs in a volume of blood
  • We need to know the percent of cells in blood from fibure in book or figure on this slide.

Conditions that affect hematocrit

  • Anemia
    • Low RBCs / unit volume.
    • Blood loss
    • Accelerated destrction
    • Poor produciton
  • Polycythemia
    • High RBCs / unit volume.
    • Reactive polycythemia = low plasma (but normal RBC)
    • True polycythemia = increase in RBC / unit volume
      • Living at altitude

Laboratory 7: Blood

Prep

  • Look at the feathered edge.
  • Scan at 10x.
  • Find each type of blood cell in slide 18.
  • In the colon (99), see lymphocytes and such in loose connective tissue.
  • Look at bm (21) for lymphocytes.
    • Hard to look at because hard to section.
    • Look for large megakaryoctyes.
  • Look for sinusoids in bm (21)
    • Look for RBCs with macrophages surrounding them.
    • Look for sinusoidal units.

Peripheral blood

Slide 18 blood smear

  • Wright stain was used on this blood stain.
  • RBC's ........................ pink.
    • Nuclei. ........... absent.
  • Neutrophils
    • granules ................ small, pink to light purple.
    • cytoplasm ............ .light pink.
    • nucleus ................. lobulated, blue or purple.
  • Eosinophils
    • granules ................. large, red to orange.
    • nucleus ................. .lobulated, blue or purple.
  • Basophils
    • granules ................. .large, dark blue to purple or black, often mask nucleus.
  • Lymphocytes
    • cytoplasm ............... light pink to deep blue, scant amount.
    • nucleus .................... round, deep blue or purple
  • Monocytes
    • cytoplasm .............. gray to blue.
    • nucleus ................. .less intense blue than lymphocyte, has open areas
  • Platelets .......................... purple.
  • A differential count is a count of 100 cells and then describing the percent of those 100 cells by their identities.
    • Look in a field and identify the first 100 cells you see. Average the counts over four observations.
    • See Basic Histology, table 12-2 for standard ranges.

Slide 99 colon

  • locate regions of very loose connective tissue. Look, also, for cells within blood vessels.
  • Neutrophils can be identified by their segmented nuclei.
  • Eosinophils stand out because they contain bright red granules.
  • Lymphocytes and plasma cells can be found in the loose connective tissue that lies beneath the colonic epithelium.

BONE MARROW (MYELOID TISSUE)

Slide 21 bone marrow

  • also, Slide 8 bone marrow smear
  • look for segments of thin-walled sinusoids.
    • Look closely, as apparent channels running along trabecular bone surfaces may be separation artifact; the result of shrinkage and separation of soft tissue from the bone.
    • The presence of RBC's can often help to identify sinusoids.
    • The sinusoids show up as large blank circles with endothelial cells lining them.
    • This makes sense because they are cross-sections.
  • Identify megakaryocytes within medullary cords (tissue between sinusoids).
    • These cells are large (~5X bigger than any surrounding cell).
  • Look also within the cords for the intense red granulation that identifies cells of the eosinophil developmental series.


  • Note: Slides 4 and 5 used in Lab 12 on bone formation contain sinusoids within fairly well-preserved regions of bone marrow.


Slide 8 (marrow smear)

  • optional; however, this slide may be a good self-test of your understanding of blood cell development.
  • identification of the various stages in erythrocyte and granulocyte development (considerable skill needed).
  • We ask that you understand the structural features (and functional correlates) that distinguish the various stages of erythropoiesis and granulopoiesis.
  • However, you are not required to identifY these cell stages in micrographs.

Slide 18

  • Optional exercise: It is not uncommon to find late stages in erythrocyte or granulocyte development in a peripheral blood smear. lf you feel you have time, try going back to slide 18 (peripheral blood) to see if you can fmd immature cell stages.
  • Polychromatophilic and orthochromatophilic erythroblasts
    • Look for cells that are about the same size as an erythrocyte, but that still contain a nucleus.
  • Neutrophilic band cells (stab cells) are relatively easy to find in slide 18.
    • A key feature of the band cell is its "band" shaped nucleus (can be U, horseshoe shaped).
    • Your text and the atlases each have good examples of these cell types.


  • stopped here on 01/24/11 at 3PM.
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