1. Week 2 Microscopic AnatomySB

2. Objective 1: The Compound Light Microscope
Ocular lens
Revolving nosepiece
Objective lenses
Arm
Stage clips
Mechanical stage
Coarse adjustment knob
Substage light
Fine adjustment knob

3. Can you name the following parts and their function?
How about part number: 9 3 5 1

4. Objective 3: Terms Relating to the Light Microscope
Total magnification (TM) is calculated by multiplying the magnification of the objective lens by the magnification of the ocular lens TM = (Objective lens) x (Ocular lens) TM is required on lab worksheets Don’t forget the “X” symbol!

5. Try these:
The total magnification of this Ə is 40X. The magnification of the ocular lens is 10X.
Which objective lens was used?
The total magnification of this Ə is 400X.
Which objective lens was used?

6. Focusing Procedures Slide placement
Place slide on stage with clip on side of slide (not on top)
Ocular lens adjustment & focusing
Start with lowest objective (4X) and bring specimen into focus, using coarse adjustment knob first, then fine adjustment knob
Move to 10X objective and focus again, only using fine adjustment
If necessary, move to 40X objective
If necessary, add immersion oil to slide and move to 100X objective
Light adjustment - You can adjust:
Dimmer
Diaphragm
Substage condenser
Remember – as magnification gets stronger you see a smaller part of the specimen

7. Microscope Care & Handling
          
Always use both hands when transporting the microscope
Clean lenses before and after use
Never use anything but lens paper to clean lenses
If it doesn’t have the word lens in it, don’t use it to clean the lens
When you are finished, rotate the nosepiece to the lowest power objective
Position the lens as close to the stage as possible
Make sure you have removed the slide
Return the microscope to its proper place

8. Objective 4: Specimen Preparation
There are several ways a specimen can be prepared for light microscopy:
Wholemount the entire structure is mounted on the slide
Section a thin slice of a tissue or organ is placed on a glass slide
Smear most suitable when viewing cell suspensions such as blood, urine, mucus, cyst fluid, etc.
Squash cells are broken by applying pressure to the slide, intracellular contents are liberated;
for example: chromosomes

9. Objective 4: Specimen Preparation
Whole Mount
Longitudinal Section
Cross Section
Squash
Drop or Smear

10. Whole Mount Preparation

11. A Smear Preparation
What might these be?

12. A Squash Preparation
Human Chromosomes

13. Staining
The majority of specimens are stained with a combination of dyes that highlight differences between cellular structure
This is a hematoxylin and eosin stained section of the kidney. The darker blue structures are the nuclei of the cells.

14. Some Common Stains Used in Histology or: You can’t judge a slide by its color
Liver: Hematoxylin and eosin
Liver: Iron stain

15. Always remember, structures, organs, and even individual cells can be sectioned in different planes.
Does this sound familiar?

16. Different planes of section through the seminiferous tubules of the testes

17. Objective 5: Structure and Function
Cells come in all different shapes and sizes. Structure and function are intimately related!
Sperm Cells
Skeletal Muscle Cells
Squamous Cells
Adipose Cell

18. Some more examples Goblet cells in trachea Simple squamous epithelium
Astrocytes, cells in the nervous system
Erythrocytes

19. Objective 6: Embryonic Germ Layers
The embryonic germ layers are ectoderm, mesoderm, and endoderm
They will give rise to all the different tissues and organs of the body

20. Section taken from a blastocyst, around the 2nd week of development
Embryonic Germ Layers
Section taken from a blastocyst, around the 2nd week of development

22. Lab Worksheets Do your own work Read directions carefully
Remember Academic Honesty
Read directions carefully
Fill in all answers
Total magnification
All labels
If you aren’t sure what you are looking at in the microscope, please ask
I can look over your drawings before you leave lab
Always turn in your worksheet before you leave!