So why, exactly, is it that we should consume a lot of fibe
r in our diet to remain healthy? Are refined fiber supplements just as good as, say, an "apple a day?"
Recently, an article in the journal Cell
answer seems to verify some of the answers
As the paper cited below indicates, research seems to confirm that dietary fiber provides nutrients for the inhabitants of our intestinal microbiome.
When dietary fiber is missing, then the microbes undergo a shift in populations and start consuming our GI mucus as an alternate source of nutrition. That, as you might guess, reduces the thickness of the protective mucus
—hus increasing the likelihood that pathogens can more easily attack the intestinal lining. Ouch.
Apparently, refined prebiotic fibers don't fix the problem.
Here are some highlights of the research article (quoted from their online preview
- Characterized synthetic bacterial communities enable functional insights in vivo
- Low-fiber diet promotes expansion and activity of colonic mucus-degrading bacteria
- Purified prebiotic fibers do not alleviate degradation of the mucus layer
- Fiber-deprived gut microbiota promotes aggressive colitis by an enteric pathogen
What can we use from this in teaching undergraduate A&P?
- When asked by students about dietary fiber, you have more information from which to draw an answer.
- When discussing any of these topics, you'll now have a bit more to add to your story:
- function of mucus
- the human microbial system (or specifically, the GI microbiome)
- how pathogens cause disease (or specifically, GI disorders)
Want to know more?Veggies and Intact Grains a Day Keep the Pathogens Away
A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility
- Francesca S. Gazzaniga. Dennis L. Kasper. Cell. Available online 17 November 2016
- Brief preview of the M. Desai article cited below.
- Mahesh S. Desai et al. Cell, Volume 167, Issue 5, 17 November 2016, Pages 1339-1353.e21
- The detailed research article.
- Kevin Patton. The A&P Professor. Various dates.
- Collection of previous posts on this topic from this blog.
I always thought of pre-testing
as something you do before working on a unit of content, later followed up with a post-test. Comparing pre-test results with post-test results can then be used as part of the course assessment
to find out what, if any, learning has happened. But that's no longer my first thought
when I hear the term "pre-test."
Several years ago, I ran across a news item that referred to a piece of learning science research that described another use for pre-testing. It showed that students who took a pre-test did better than students who did not take a pre-test. It showed, I think, that just the process of pre-testing primes student learning in a way that has a demonstrable and significant effect on student success.
As with any new way of doing things that I discover, I had to let it percolate in the back of mind for a while. First, do I really believe it? Further research showed me that this was not a one-off experiment—it's been tested in both the lab and in the field with similar outcomes. Next, will it work in my courses? If so, how would I implement it? And the all-important question: would I have time to implement it? Would it then add extra effort and time to my workload every semester, in perpetuity?
Well, I finally jumped in and tried it. I figured it could do no harm. And I found a way to do it without much effort—either in initially wedging it into my course or in maintaining it across all future courses.
I'd already been using frequent online tests,
each allowing multiple attempts, as a way for my students to prepare for their written exams. Each online test has a test bank of many more items than appear on any one attempt. Each test item is pulled from a group of items relating to the same learning outcome, so tests end up being different in every attempt.
By using just a handful of items in each group, the odds quickly become astronomical that a student will get the same test twice—or get the same test as any other student in the course. Sort of like the classic type of slot machine.
My existing online tests were already cumulative.
They included test item groups from previous tests, so that students have continuing practice with concepts introduced throughout the course, as explained in my recent article, Cumulative Testing Enhances Learning
What I did to make the pretests is simply go into my online test editor (Respondus
) and make a copy of each online test. Then I removed the cumulative item groups
from each test, leaving only the item groups that pertain to that particular unit of study. An easy and quick job
in the test editor. Then I saved those as pre-tests and uploaded them to my learning management system (LMS). And set them up for ONE attempt only (not the usual three possible attempts).
What?! Using the same test items as their "real" test? Isn't that just like handing them a list of answers? Glad you asked! Remember, the odds of anyone ever getting "the same test" again (or as anyone else gets) is astronomically low. What they get in the pre-test is a "version" of the real test, but not the actual test that individual will end up taking later.
I then set up my LMS so that each pre-test opens about halfway through the preceding unit. Students can go into the LMS before their next unit to take the pre-test for the upcoming unit. I also set things up so that students do not have access to the course resources they need to get through the unit until after they submit the pre-test.
For example, I use online Previews
as part of my sorta-flipped format (I called it a half-flip with a quarter turn
). If they don't take the pre-test first,
then neither the Previews, nor anything else, will open up for them.
Because the "locks" that unlock the other course resources give students incentive to do the pretests, I didn't need to assign grade points or deduct grade points if they didn't do it. My pre-tests do not impact the grade directly—only indirectly by enhancing student learning.
I have been amazed at the results of that simple step. I noticed that class performance increased right away—and there has been no downward trend since then. So I guess I shoulda believed the research data when I first saw it, eh?
I think there are several things going on.
For one, pre-tests give students an overview
of what they'll be expected to solve at the end of the unit. And they'll get a chance to use what they know already to predict what might be a correct answer—with immediate feedback on where they predicted incorrectly. This prediction
exercise can be a powerful learning strategy.
Also, as they then struggle through the unit, they have in mind what they need to master
if they're going to have a chance of passing the test.
Along the same lines, they gain some familiarity with the upcoming material. They'll have "seen this all before" even if they don't fully understand it. As we go through it all after the pre-test, students will have already walked through that neighborhood, so it's not so unfamiliar to them.
I think pre-testing also shakes loose some prior learning. That is, students will recognize some basic principles and some patterns that they've seen before. I suggest that this stimulates their awareness of how things connect and thus gets them better prepared for their new learning.
One last thing I want to mention: I now have another assessment tool that I can use to compare before-after data and get a sense of what my students have accomplished. Even better, I suppose, is that I added a column to their LMS gradebook that calculates their "gain" by providing the percentage by which they improved between the pre-test and the real test (post test). Individuals seeing that they learned a lot in each unit is a real motivator for continued hard work in the course.
As with anything, there are potential pitfalls. The one that I didn't anticipate, but should have, is that the super-high-achievers will NOT want a "bad grade" anywhere in their gradebook. Even though students are EXPECTED TO FAIL the pre-test—and it isn't part of the course grade calculation. It's a mindset—it doesn't have to make sense.
So I would have these high-achievers in my office the day after they took their pre-test and want me to go over every item with them. I'll bet their blood pressure wasn't normal that day, either—probably even worse the night before. The solution I found, which is not 100% effective, is to repeatedly remind students that they are expected to do poorly on the pre-tests. And that they should not struggle with it—just think a moment, then give your best guess and move on.
Like any unfamiliar teaching strategy, pre-testing works best if you tell students how they will benefit.
If any of you have experiences with pre-testing that you'd like to share, please comment at the blog site, in the form below this article.
Want to know more?
Testing in A&P Courses
- Kevin Patton. The A&P Professor. Collection (various dates).
- An assortment of brief articles on methods and issues regarding testing in the undergraduate A&P course.
Cumulative Testing Enhances Learning
- Kevin Patton. The A&P Professor. 5 Sep 2016.
- Article on how cumulative testing can be used to promote long-term learning in A&P courses.
The pretesting effect: Do unsuccessful retrieval attempts enhance learning?
- Richland, Lindsey E.; Kornell, Nate; Kao, Liche Sean. Journal of Experimental Psychology: Applied, Vol 15(3), Sep 2009, 243-257.
- Research article describing experiments in pre-testing.
Small Teaching: Everyday Lessons from the Science of Learning
- James M. Lang. Jossey-Bass, San Francisco. 2016.
- If you don't read anything else on teaching-learning this year, at least read this. Lang's clear writing, chunked into small chapters, reviews some of the major contemporary insights with practical "small" things you can do in your class to improve learning. Part I, Chapter 2, discusses pretesting.
It's true. Like most of you, I have a long list
of tasks that need to be done in any one day or week.
I am pretty good about remembering what I have to get done by when, what I've already finished, and what has just been added to my plate. But my brain is not 100% reliable with that, so I make lists.
Sometimes these are lists on my computer desktop or in my online Task List
. But those are too easily hidden. I have to see them
to be reminded. So I often make paper lists. There is something very satisfying
about having the kinesthetic experience of physically ticking something off my list with my trusty green pen.
I was talking about this last summer when I was presenting a bunch of practical tips to help textbook authors stay on track at the Textbook and Academic Authors
conference. During the talk, my buddy Mike Kennamer
tweeted, "'Checkmarks make me happy...' Kevin Patton".
When I saw that tweet later in my Twitter feed, I chuckled that he took this out of the discussion—but I also realized how important
a point that it is.
Whether it's a textbook revision or a long semester of teaching A&P, those little surges of dopamine
that happen when we can check something off our lists really do help keep us motivated.
Seeing the progress we are making as we add ticks to our checklists provides some additional satisfaction, which also helps keep us going.
And checklists also keep us from forgetting
important things to do.
In an online course
I teach, it's easy to forget
what needs to be graded each week because there are no stacks of tests or papers sitting there on my desk glaring at me. Those assignments are hidden away on a server
somewhere and I need to intentionally call them up to grade them. So I need a checklist.
the one pictured here lists grading duties organized by module (we have two-week modules A, B, C,...) and by week.
Each Friday, during my scheduled grading session,
I look at my checklist. I note that, even though it may not always feel like it, the trimester is actually progressing. And I see what I need to grade this week. And—hooray!—I get to check it off my list when I'm done. What a great way to start the weekend, eh?
I recently posted my grading checklist in that online course. It's a bit late for this last term, but next time I teach the course, my students can print out my checklist
to help them keep track of what they've submitted each week. Sure, they have a syllabus. Like they're going to use that
to make their own list? Really? What planet do you live on?
What can we use from this in teaching undergraduate A&P?
- Grading checklists help us make sure that no graded assignments fall through the cracks.
- Grading checklists provide happiness and motivation. At least a little.
- Scheduled grading sessions help us keep up with our grading tasks, preventing them from piling up and disturbing our mental health.
- We can share grading checklists (and an exhortation to use them) with students to help keep them on track—and stay motivated.
A recent report
in the journal Science
proposed a big change
in how we understand the sympathetic and parasympathetic pathways of the autonomic nervous system (ANS).
In a nutshell, the new model stipulates that the outflow (efferent pathways) are divided into a cranial division and spinal division—not the craniosacral
divisions that we learned (and that exist in all A&P textbooks):
- Craniosacral division (parasympathetic outflow)
- Thoracolumbar division (sympathetic outflow)
- Cranial division (parasympathetic outflow)
- Spinal division (sympathetic outflow)
The authors lay out embryological and genetic phenotype evidence to show that the sacral components of the ANS outflow pathways are similar to sympathetic thoracic pathways—not to cranial parasympathetic pathways as we have long supposed.
But wait, you say, what about the parasympathetic control of the genitals, rectum, bladder? What about, well, all kinds of things that now seem to unravel? I suggest reading the rather brief and plainly written article in Science for the full answer.
However, a few quick points may reduce your blood pressure a bit—and perhaps pique your interest.
Quick points about the new ANS model
- Thoracic and sacral pathways share common embryologic development by location and when looking at transcriptional markers associated with neurotransmitters that differ from the developmental pattern of cranial pathways.
- Thoracic and sacral pathways have a ventral exit point from the spinal cord; cranial pathways have a dorsal exit point.
- The pelvic ganglion has been considered a "mixed" sympathetic/parasympathetic ganglion because it receives fibers from both the upper lumbar and sacral segments. But if the sacral pathways are sympathetic, the pelvic ganglion is clearly a sympathetic ganglion (not mixed).
- Analyses of transcription factors show that cells of the pelvic ganglia resemble those sympathetic ganglia and do not resemble cells in cranial ganglia.
- The supposed lumbar vs. sacral antagonism in the urinary bladder's detrusor muscle does not seem to hold up, with the lumbar inhibitory effects either not demonstrable in experiments or of questionable functional relevance.
- The effects on vessel dilation in genitals can be explained as a "continuity of action—rather than antagonism"
- The sacral pathway to the rectum seems to resemble sympathetic structure, not cranial (parasympathetic) structure.
What can we use from this in teaching undergraduate A&P?
- When covering the craniosacral/thoracolumbar scheme, consider mentioning this newly proposed model.
- Consider using this scenario to illustrate the dynamic nature of science. Perhaps discuss that long-held dogma is occasionally challenged using newer methods and ways of thinking.
- Consider discussing pros and cons of adopting the new model. For example, can evidence from mice extend to all vertebrates? Which is stronger, evidence for the current model or the new model? Which model is most useful in understanding principles of ANS regulation? A little critical thinking never hurt anyone (at least not much).
Want to know more?
The sacral autonomic outflow is sympathetic
Neural circuitry gets rewired
- I. Espinosa-Medina, O. Saha, F. Boismoreau, Z. Chettouh, F. Rossi, W. D. Richardson, J.-F. Brunet. Science 18 Nov 2016: Vol. 354, Issue 6314, pp. 893-897 DOI: 10.1126/science.aah5454
- Peer-reviewed research report describing this discovery, Includes an updated version of the classic diagram of sympathetic and parasympathetic pathways.
The Autonomic Nervous System. Part I.
- Adameyko, I. Science 18 Nov 2016: Vol. 354, Issue 6314, pp. 833-834 DOI: 10.1126/science.aal2810
- Companion article to the report cited above, stating that "This finding provokes a serious shift in textbook knowledge, and, as with any fundamental discovery, it brings important practical implications..." and goes on to mention of a few of the implications (e.g., how to treat bladder dysfunction).
- John Newport Langley. W. Heffer & Sons Ltd., Cambridge, 1921.80pp.
- Classic "primary source" that codified the modern concept of the ANS.
Gray's Anatomy ANS diagram
- Henry Gray. 1918 (online edition at Bartleby)
- Classic diagram by Henry Vandyke Carter of ANS pathways from an early edition of Gray's Anatomy.
- my-ap.us/2fYGMaT or my-ap.us/2gcAmaW
Ever been part of a conversation among faculty about "students these days"
and how unmotivated they are, or how they lack the skills or knowledge that you'd like them to have? Yeah, me too.
Today in my daily Nuzzel newsletter,
I shared an excellent article from Faculty Focus
that does a great job of exposing the dangers of such conversations.
Dangers to students, dangers to our academic institutions, and dangers to ourselves as educators. Although the author, Maryellen Wiemer, admits that occasional venting to a trusted colleagues helps us put things in perspective, she also points out the many harms that outright chronic complaining can do.
I'm not going to summarize that article here—it's best read in it's entirety. However, I'd like to add my two cents.
After all, what's the good of having my own blog if I can't do that once in a while, eh?
It took me decades of teaching in high school and college classrooms to fully realize what I think my role as an A&P professor should be. It's not solely to guide well-prepared, self-motivated, highly skilled students to the success that they can easily achieve without me. Sure, that's easy and mostly annoyance-free. But it can be awfully boring.
What do they need me for, anyway? Not much.
I came to discover that what really rocks my boat as a professor is when I can help a struggling student achieve even a very small success.
When I can help a learning-disabled student find ways to "get it" when studying those messy histology specimens. When I can help under-prepared students "catch up" and learn some effective study skills to continue keeping up. When I can get through to unfocused, unmotivated, immature students in some small way.
We pay a lot of lip service to making our courses "student centered" and making carefully devised learning outcomes our primary goal, but we often just don't want to do the work
—or put up with the frustrations—of really making that happen.
It's when I finally started embracing those challenges
and leaving aside my unhelpful judgments
of "students these days" that I finally started truly and totally
loving teaching my A&P students. I found that the more I connected with "problem students," the closer I got to finding the underlying reasons for their apparent lack of will or ability—and thus able to help them find appropriate strategies
Sometimes, sporadic attendance is more about serious family or health issues than it is about their attitude toward my course. Sometimes, their lack of focus in my class is more about neurological issues, personal emergencies outside the classroom, or side effects of an illness or therapy, than it is about them "not caring" about their learning. Sometimes, their lack of reading is more about dyslexia than it is about laziness.
Sure, it's sometimes hard to face challenges.
Otherwise, we wouldn't call them challenges, eh? But when I ask myself, "what kind of teacher do I want to be today?"
the answer always comes back to, "the kind who is going to help even the most challenging students." And that makes all the difference.
Want to know more?
Ugly Consequences of Complaining about 'Students These Days'
- Maryellen Weimer. Faculty Focus. 16 November 2016.
- This is the article to which I refer in today's blog post.
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Want more teaching tips for A&P?
Check out my blogs for users of my textbooks:
Anatomy & Physiology
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Even if you use a different textbook, the tips and advice are interesting and helpful!
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Do you crave to keep up with the latest fashion in using (or not using) eponyms?
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