20110124 06 connective cells notes

fQfxNg Thanks for the blog post. Awesome.

[edit] Laboratory 7: Blood

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.

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.

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.

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.

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.

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.