Hints for Self Assessment Slides
- Work together in small groups. This job is challenging enough
that it helps to pool your strengths.
- Most of the SAQ slides come from autopsy specimens.
- These specimens are representative of actual clinical practice.
- Fixation and staining, and the resulting cellular detail
(or lack thereof), may not be as pretty as in textbook micrographs or
commercially prepared slides.
- Recognizable tissue features are present, even if they
are not pretty.
- Be aware that pathology or post-mortem changes may distort
expected appearances. For example, some post-mortem specimens may shed
epithelial cells from exposed mucosal surfaces. Others (notably pancreas)
will self-digest into mush. In this exercise, the hints will inform
you if there is significant pathology; otherwise, most SAQ specimens are pretty
much "within normal limits" for samples from deceased patients.
- Each slide includes one or more distinctive clues (sometimes
small and/or obscure) which should enable recognition of the source organ.
- If you begin examining these slides before you have completed ERG,
you should expect that some of the specimens will still be unfamiliar. So
don't worry if a slide seems completely alien. You might profitably
skip such slides, recording their numbers to revisit later, after you have
studied all of the E, R, and G systems.
- Slides may come from any organ of the body, not just those associated
with E, R, or G systems (e.g., skin, bone, skeletal muscle, cerebrum, cerebellum,
eye, ear, spleen, thymus, lymph node, heart, lung, trachea, kidney, ureter,
bladder, aorta, et cetera).
- Examine the entire specimen.
- Scan first with your unaided eye (or with an inverted
microscope ocular). Notice all areas that have differing textures
or staining characteristics, and make sure these are all examined microscopically.
- With the lowest-power objective, carefully survey the
borders of the specimen. Distinguish between cut edges and natural
- Natural surfaces (mucosa, serosa, intima) often present
- Also at low power, scan all solid areas.
- Determine whether solid masses represent fibrous connective
tissue, muscle (what kind?), lymphoid tissue, glandular tissue (what kind?),
- Don't jump to a conclusion. Treat specimen identification as
you would diagnosis, gathering information and then formulating and testing
- Describe basic tissue elements. Your first
response to any particular slide should be to list observations in the
most basic, non-committal terms, and evaluate these observations in terms
of personal confidence (i.e., reliability of your present observational
- List alternative hypotheses. How many different
possibilities are consistent with the most reliable of your observations?
- Test each hypothesis. Use your knowledge
of organ structure to predict additional, confirmatory observations. Make
sure that such observations are then made objectively (i.e., not "imagined",
or colored by expectations). Look thoroughly for disconfirming features
-- make sure that the entire specimen has been inspected and that
all parts are consistent with your hypothesis. (If you find
yourself saying, "I think this is X, but I can't make sense of region
Y," then maybe you should reconsider X.)
- Intuitive recognition can be powerful. But
when mistaken, it can also be powerfully misleading. Respect your
limitations, and always follow the above steps.
- Once you have the correct identification, your confidence should grow with
further examination and consideration. If you continue to feel uncertain,
you may have not yet considered the actual correct idenficiation.
Hints for individual slides.
DO NOT open these hints until you have examined the slides
(or you will spoil the fun and thwart the purpose of the exercise).
Comments and questions: firstname.lastname@example.org
SIUC / School
of Medicine / Anatomy / David
Last updated: 9 May 2005 / dgk