Department of Zoology
Southern Illinois University at Carbondale

ZOOL 409, Lab Week 5

Lab notes offer a preview of upcoming labs and links to more information about tissues examined during lab.

• Week 5 lecture notes
• SYLLABUS (including links to all note pages)
• 409 Homepage (index of course resources)
• Dr. King's School of Medicine histology page
• Slide summary

TUESDAY
Primary objectives: 

1. Recognize blood vessels.
    
• Examine the examples of artery and vein on slide 30, 74 (note that slide 74 is a trichrome stain; collagen is blue). 
  • Note the three layers.
    • intima (innermost lining, with endothelium);
    • media (usually the thickest layer, with smooth muscle);
    • adventitia (surrounding connective tissue.
  • Note elastin (especially the internal elastic lamina in the artery).
     
• Find examples of arteries and veins on additional slides.  
  

THURSDAY
Primary objectives:   

1. Recognize blood cells on normal blood smears (slide 20.)
      
• To sample a smear adequately, systematically scan an area until you have counted at least 100 white blood cells.
• Keep a running count of each type.
  • Neutrophils should be the majority, 60-65 % of the total count.
    • You might try to distinguish "band neutrophils" (or "bands") from "segmented neutrophils" ("segs").  The bands are immature; a high proportion of bands is indicative of rapid production of neutrophils.
  • Lymphocytes should also be fairly common, 20-30 %.
  • Monocytes are much less common, roughly 5%.
  • Eosinophils are rarer still, 1-4 %.
  • Basophils are quite rare, less than 1 %.  You may not find any.
     
• How does slide 21 differ from slides 20?
• How does slide 23 differ from slides 20?  (Try to find megakaryocytes, very large cells with very large nuclei.)
   
2. Recognize the special tissues/organs which comprise the immune system.
    
   • Mucosal lymphoid tissue (e.g., tonsil, Peyer's patches of ileum) -- 82, 47.
     • Try to distinguish lymph nodules with their pale germinal centers and darker "caps" with more densely packed lymphocyte nuclei.
        
   • Lymph nodes -- slides 16, 36.
     • Look for capsule, cortex with lymph nodules, medulla.
        
   • Spleen -- slides 81.
     • Look for capsule, trabeculae (narrow bands or small patches of dense fibrous connective tissue).
     • Distinguish white pulp (patches densely packed with lymphocytes, typically with small arteries in the center) from red pulp (background texture, with more red blood cells than in the white pulp).
     • Notice lymph nodules, most often associated with white pulp.
        
   • Thymus-- slides 58, 59.
     • Notice lobular organization; in each lobule distinguish cortex and medulla (with cortex having cells more densely packed).
     • Notice Hassall's corpuscles.
     • Notice absence of lymph nodules.
        

Complete slide list:
01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100

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