Wednesday, November 6, 2013

New knee ligament confirmed

It's been there all along.  In most of us, at least.  Back in 1879, French surgeon Paul Ferdinand Segond first described it as it related to a particular type of avulsion fracture of the knee—the Segond fracture. But it was never really confirmed as separate from the joint capsule and named as a normal ligament of the human knee.  Until now.

Dubbed the anterolateral ligament (ALL), it originates at the prominence of the lateral femoral epicondyle (just anterior to the lateral collateral ligament) and running obliquely to the anterolateral part of the tibia (attached at the lateral meniscus).

Segond
So maybe we should pencil the ALL into our anatomic atlases, eh?  And wait for some research to confirm its biomechanical function—probably related to controlling internal rotation of the tibia.

This might also provide a good opportunity to talk about the dynamic nature of anatomical science—and the fact that human anatomy is not "finished."



Want to know more?

Anatomy of the anterolateral ligament of the knee
  • Steven Claes et al. Journal of Anatomy. Volume 223, Issue 4, pages 321–328, October 2013 (First published online: 1 AUG 2013) DOI: 10.1111/joa.12087
  • This the original journal article (free abstract).
  • my-ap.us/1aFUVV3

The Anterolateral Ligament of the Knee: Anatomy, Radiology, Biomechanics and Clinical Implications
  • Steven Claes, et al. American Academy of Orthopedic Surgeons (AAOS) Annual Meeting, SE73, 20 March 2013
  • This is an abstract (with image) of a preliminary presentation giving prior to journal publication.
  • my-ap.us/1b7bU0Q

Photo of the ALL
  • Steven Claes, et al. American Academy of Orthopedic Surgeons (AAOS) Annual Meeting, SE73, 20 March 2013
  • my-ap.us/1cF4sgC

Diagram of ALL



Monday, October 7, 2013

Nobel Prize: Vesicle Transport

The Nobel Assembly at Karolinska Institutet has today decided to award the 2013 Nobel Prize in Physiology or Medicine jointly to James E. Rothman, Randy W. Schekman and Thomas C. Südhof for their discoveries of machinery regulating vesicle traffic, a major transport system in our cells.

Those of you now teaching A&P 1 have probably recently covered the essential concepts vesicle transport and have perhaps already had the opportunity to apply them to specific functions of the body such as the release of acetylcholine at the neuromuscular junction.  Bringing up today's news gives us a great chance to underscore the importance of a topic that many students wonder, "why do we have to know this?"

Near the bottom of  this post, you'll find a link to a nice handout that you can distribute to your class (or link to from an email or webpage).  I've often added a question on my midterm exam covering that year's relevant Nobel Prize concept.

Summary

The 2013 Nobel Prize honors three scientists who have solved the mystery of how the cell organizes its transport system. Each cell is a factory that produces and exports molecules. For instance, insulin is manufactured and released into the blood and chemical signals called neurotransmitters are sent from one nerve cell to another. These molecules are transported around the cell in small packages called vesicles. The three Nobel Laureates have discovered the molecular principles that govern how this cargo is delivered to the right place at the right time in the cell.

Randy Schekman discovered a set of genes that were required for vesicle traffic. James Rothman  unravelled protein machinery that allows vesicles to fuse with their targets to permit transfer of cargo. Thomas Südhof revealed how signals instruct vesicles to release their cargo with precision.

Through their discoveries, Rothman, Schekman and Südhof have revealed the exquisitely precise control system for the transport and delivery of cellular cargo. Disturbances in this system have deleterious effects and contribute to conditions such as neurological diseases, diabetes, and immunological disorders.

How cargo is transported in the cell

In a large and busy port, systems are required to ensure that the correct cargo is shipped to the correct destination at the right time. The cell, with its different compartments called organelles, faces a similar problem: cells produce molecules such as hormones, neurotransmitters, cytokines and enzymes that have to be delivered to other places inside the cell, or exported out of the cell, at exactly the right moment. Timing and location are everything. Miniature bubble-like vesicles, surrounded by membranes, shuttle the cargo between organelles or fuse with the outer membrane of the cell and release their cargo to the outside. This is of major importance, as it triggers nerve activation in the case of transmitter substances, or controls metabolism in the case of hormones. How do these vesicles know where and when to deliver their cargo?

Traffic congestion reveals genetic controllers

Randy Schekman was fascinated by how the cell organizes its transport system and in the 1970s decided to study its genetic basis by using yeast as a model system. In a genetic screen, he identified yeast cells with defective transport machinery, giving rise to a situation resembling a poorly planned public transport system. Vesicles piled up in certain parts of the cell. He found that the cause of this congestion was genetic and went on to identify the mutated genes. Schekman identified three classes of genes that control different facets of the cell´s transport system, thereby providing new insights into the tightly regulated machinery that mediates vesicle transport in the cell.

Docking with precision

James Rothman was also intrigued by the nature of the cell´s transport system. When studying vesicle transport in mammalian cells in the 1980s and 1990s, Rothman discovered that a protein complex enables vesicles to dock and fuse with their target membranes. In the fusion process, proteins on the vesicles and target membranes bind to each other like the two sides of a zipper. The fact that there are many such proteins and that they bind only in specific combinations ensures that cargo is delivered to a precise location. The same principle operates inside the cell and when a vesicle binds to the cell´s outer membrane to release its contents.

It turned out that some of the genes Schekman had discovered in yeast coded for proteins corresponding to those Rothman identified in mammals, revealing an ancient evolutionary origin of the transport system. Collectively, they mapped critical components of the cell´s transport machinery.

Timing is everything

Thomas Südhof was interested in how nerve cells communicate with one another in the brain. The signalling molecules, neurotransmitters, are released from vesicles that fuse with the outer membrane of nerve cells by using the machinery discovered by Rothman and Schekman. But these vesicles are only allowed to release their contents when the nerve cell signals to its neighbours. How is this release controlled in such a precise manner? Calcium ions were known to be involved in this process and in the 1990s, Südhof searched for calcium sensitive proteins in nerve cells. He identified molecular machinery that responds to an influx of calcium ions and directs neighbour proteins rapidly to bind vesicles to the outer membrane of the nerve cell. The zipper opens up and signal substances are released. Südhof´s discovery explained how temporal precision is achieved and how vesicles´ contents can be released on command.

Vesicle transport gives insight into disease processes

The three Nobel Laureates have discovered a fundamental process in cell physiology. These discoveries have had a major impact on our understanding of how cargo is delivered with timing and precision within and outside the cell.  Vesicle transport and fusion operate, with the same general principles, in organisms as different as yeast and man. The system is critical for a variety of physiological processes in which vesicle fusion must be controlled, ranging from signalling in the brain to release of hormones and immune cytokines. Defective vesicle transport occurs in a variety of diseases including a number of neurological and immunological disorders, as well as in diabetes. Without this wonderfully precise organization, the cell would lapse into chaos.

About this year's Nobel laureates

James E. Rothman was born 1950 in Haverhill, Massachusetts, USA. He received his PhD from Harvard Medical School in 1976, was a postdoctoral fellow at Massachusetts Institute of Technology, and moved in 1978 to Stanford University in California, where he started his research on the vesicles of the cell. Rothman has also worked at Princeton University, Memorial Sloan-Kettering Cancer Institute and Columbia University. In 2008, he joined the faculty of Yale University in New Haven, Connecticut, USA, where he is currently Professor and Chairman in the Department of Cell Biology.

Randy W. Schekman was born 1948 in St Paul, Minnesota, USA, studied at the University of California in Los Angeles and at Stanford University, where he obtained his PhD in 1974 under the supervision of Arthur Kornberg (Nobel Prize 1959) and in the same department that Rothman joined a few years later. In 1976, Schekman joined the faculty of the University of California at Berkeley, where he is currently Professor in the Department of Molecular and Cell biology. Schekman is also an investigator of Howard Hughes Medical Institute.

Thomas C. Südhof was born in 1955 in Göttingen, Germany. He studied at the Georg-August-Universität in Göttingen, where he received an MD in 1982 and a Doctorate in neurochemistry the same year. In 1983, he moved to the University of Texas Southwestern Medical Center in Dallas, Texas, USA, as a postdoctoral fellow with Michael Brown and Joseph Goldstein (who shared the 1985 Nobel Prize in Physiology or Medicine). Südhof became an investigator of Howard Hughes Medical Institute in 1991 and was appointed Professor of Molecular and Cellular Physiology at Stanford University in 2008.



Want to know more?


Handout showing mechanisms for which this prize was awarded

  • Diagrams and brief description of the contributions of each Nobel laureate
  • my-ap.us/1cnPDhF


Machinery Regulating Vesical Traffic, A Major Transport System in our Cells

  • Nobelprize.org accessed 7 October 2013
  • [Nice summary of the scientific concepts involved.  An expanded version of the handout, with additional diagrams and explanations.]
  • my-ap.us/GDLiZR


Original Journal Articles

  • Seminal papers describing the original work of this year's Nobel Laureates
  • Novick P, Schekman R: Secretion and cell-surface growth are blocked in a temperature-sensitive mutant of Saccharomyces cerevisiae. Proc Natl Acad Sci USA 1979; 76:1858-1862.
  • Balch WE, Dunphy WG, Braell WA, Rothman JE: Reconstitution of the transport of protein between successive compartments of the Golgi measured by the coupled incorporation of N-acetylglucosamine. Cell 1984; 39:405-416.
  • Kaiser CA, Schekman R: Distinct sets of SEC genes govern transport vesicle formation and fusion early in the secretory pathway. Cell 1990; 61:723-733.
  • Perin MS, Fried VA, Mignery GA, Jahn R, Südhof TC: Phospholipid binding by a synaptic vesicle protein homologous to the regulatory region of protein kinase C. Nature 1990; 345:260-263.
  • Sollner T, Whiteheart W, Brunner M, Erdjument-Bromage H, Geromanos S, Tempst P, Rothman JE: SNAP receptor implicated in vesicle targeting and fusion. Nature 1993; 362:318-324.
  • Hata Y, Slaughter CA, Südhof TC: Synaptic vesicle fusion complex contains unc-18 homologue bound to syntaxin. Nature 1993; 366:347-351.

Related textbook content

  • Anatomy & Physiology 8th ed.  Chapter 3 (see p. 75, 82), Chapter 4 (see p. 99-100), and throughout book my-ap.us/QZTbK1
  • Essentials of Anatomy & Physiology Chapter 3 (see p. 52), Chapter 4 (see p. 69), and throughout book my-ap.us/SCfNlj  
  • The Human Body in Health and Disease 6th ed. Chapter 3 (see p. 49, 56) and throughout book my-ap.us/X71LJO 
  • Structure & Function of the Body 14th ed. Chapter 3 (see p. 48, 53) and throughout book http://my-ap.us/10s50MH


Portions of this post adapted from Nobel Prize news release

Monday, September 16, 2013

Teaching bones & bone features

I've found that one of the things that stand in the way of student success in learning the anatomy of the skeleton is that they don't know the underlying language.

If they already knew that a foramen is a hole and a condyle is a bump, then they could make short work of identifying and learning a long list of bones and bone features. And they'd have a better understanding of the concepts, plus an easier time remembering each structure for the long term.

We can't do anything about the fact that they just don't teach Latin as a required subject  in grade schools and high schools anymore.  But that doesn't mean there's nothing we can do to give them a head start on learning the skull!

For a long time, I've started out my students learning the general types of bone features before starting on the specific skeletal structures.  I find that they have a much easier time identifying structures because they have a better understanding of what the bone names mean.  They know they're looking for a hole when they get to the foramen ovale.  That oblong dark spot in the skull diagram or photo could be a bump, for all they know.

I use the list of general types of bone features found in my textbooks, lab manuals, and other publications (see list below).  I've also provided you with a downloadable version of this list you can link to in your course or distribute as a handout (see links below).

I've just uploaded two videos to my YouTube channel that help students get started this way.  You can link to the videos in an email, syllabus, or LMS; embed them in your course website or LMS; or embed them in a PowerPoint slide.  Or you could use the slides I used in the video to make your own video or live presentationperhaps even customize it for your course.  This links to all of these resources are below.

I'll be posting these videos on my study-tip blog for students, The A&P Student, soon.  If your students are not yet using this blog, you can distribute my FREE bookmarks to get them started.  See below for details.



Want to know more?

Bone Names Have Meaning - Part 1 - Get Started (video)
  • by Kevin Patton, Kevin's YouTube Channel,  uploaded September 2013
  • Video briefly explains the importance of knowing the meaning of bone names and how to get started doing that.  Includes link to list of bone features.
  • Link URL: youtu.be/heBjZIZP328
  • Embed code is available once you link to the above URL and click "Share"
Bone Names Have Meaning - Part 2 - Types of Bone Markings (video)
  • by Kevin Patton, Kevin's YouTube Channel, uploaded September 2013
  • Brief video runs through each of the major bone feature types, showing one or more examples. Includes link to list of bone features.
  • Link URL: youtu.be/NRR-t93jyFw
  • Embed code is available once you link to the above URL and click "Share"
Bone-Names-1-2 (PowerPoint slides)
  • by Kevin Patton, Lion Den Slide Collection,  September 2013
  • Download these animated slides I used to make the videos and use them in your recorded or live presentation.  The slide notes include the narration, which you could customize (or ignore).  You can use some or all of the slides.
  • To get the download password, fill out the form at lionden.com/slides-form.htm
Bone Names (web page)
  • by Kevin Patton, Lion Den Study Tips & Tools
  • Web page for students briefly outlining how to get started learning bone structures. The videos above are embedded in the page, so you could link to this page in your course instead of linking to the individual videos.  Links to related, downloadable lists. Part of the Field Guide to the Body.
  • lionden.com/tips-lab-anatomy-bone-names.htm
List of Bone Markings
Lion Den Slide Collection
  • by Kevin Patton, Lion Den Slide Collection
  • Download all kinds of  animated slides you can use in your own course to supplement your own slides and those provided with your textbook or school. Most slides are animated.
  • To get access to the whole collection, fill out the form at lionden.com/slides-form.htm
Free Bookmarks
  • Get packs of 50 bookmarks to distribute to students.  The bookmarks tell students how to access The A&P Student blog, which has a collection of study tips for A&P.
  • theapprofessor.org/free-bookmarks.html

Monday, August 19, 2013

Death spreads throughout body

C. elegans
In class discussions, we talk about what happens when the body dies.  And it's always a bit tricky when the discussion gets around to the idea that not every cell dies simultaneously.

And of course, that can lead to a discussion of how tissue death occurs, even in the case of necrosis that occurs as a result of ischemia or other damage. There are certainly many mechanisms involved—quite a few of which have yet to be clarified.

Recently, researchers have brought a step closer by mapping out some of these mechanisms.  In their report (cited below), they reveal that in the gut of the C. elegans worm, calcium ions flowing into cells cause the lysosomes to burst suddenly.  And we know what that means! Intracellular destruction leading to cell death.

What causes the calcium ions to rush into the cells? Gap-junction ion-channel proteins called innexins (analogous to connexins in humans) open up and allow calcium ions to flow into one cell then the next, producing a wave of destruction along the gut.

In interesting phenomenon is that esters of anthranilic acid (formed from the amino acid tryptophan) in the lysosomes not only produce acidosis in the cytosol, they also fluoresce brightly with a bluish glow during this process of cell death.

The video below shows an amazing anterior-to-posterior wave of fluorescent blue in C. elegans worms as this "wave of death" travels along the gut wall.



Okay, now here's the kicker.  By knocking out the innexin channels, the researchers were able to stop the wave of death!  Whoa!  A cure for . . . death?!

Not so fast.  This worked in a WORM, which is not as complex as a vertebrate like the human.  And it only worked in INJURED worms, not elderly worms dying of old age.  So it won't stave off death entirely—or unusually prolong life—but it could lead to treatments for preventing or reducing necrosis that occurs as a result of ischemia and other injuries.

This information—and that dramatic video—could be an interesting addition to your class.  It ties in why it's important to understand concepts such as:

  • ions
  • amino acids
  • ion flow into cells
  • gap-junction ion channels
  • lysosomes
  • cell death and organismal death
  • necrosis (and factors leading to necrosis)
  • use of animals in research
  • the intersection of basic science research and medical applications

Want to know more?


Anthranilate Fluorescence Marks a Calcium-Propagated Necrotic Wave That Promotes Organismal Death in C. elegans. 

  • Coburn C, et al.  PLoS Biology 11(7): e1001613. 2013. doi:10.1371/journal.pbio.1001613
  • The original research article.  Includes FREE images and PowerPoint slides you can use in your course.
  • my-ap.us/19SRjOG


Glowing, Glowing, Gone: Cell Fluorescence Casts Light on How Death Spreads Throughout Body

  • By Christopher Crockett. Scientific American online 2 August 2013
  • Brief, less technical, article explaining that researchers have identified a key molecular pathway for animal death that may provide clues for better managing traumatic injury and disease in humans.
  • my-ap.us/13MxJjs


Monday, August 5, 2013

Spelling IS important

In A&P, correct spelling could be a life-or-death issue.  Really.

The topic of correct spelling—and the consequences of incorrectly spelled terms—was brought to mind recently with the news story about a student on the TV game show Jeopardy! whose answer was disqualified because it was misspelled. A lot of folks were angry, as though the boy was cheated, but the producers calmly pointed out that it’s not an acceptable answer if it’s not spelled correctly.  Like Scrabble or Words with Friends, Jeopardy! is a game with rules, after all.

But the A&P course is not “just a game.”  It is the foundation for many health professions.  Professions where misspellings can be the basis for life-threatening medical errors

A few years ago, I called our attention to Doing our part to reduce medical errors by enforcing accuracy in our courses—including correct spelling of scientific and medical terms.

Here’s what I tell my own students:
“That's part of learning how to communicate accurately and professionally. For those of you going into patient care or managing patient records, accuracy can affect a person's life . . . so it's best to learn that lesson here and now—where no one's life is in danger.”
There really IS a difference between perineum and peritoneum.  Just two letters, and the whole meaning of a sentence or paragraph—or medical record—is changed. It may still make sense, even in context, but is now wrong.

Some of my students counter that current software platforms used in hospitals and clinics have safety features that autocorrect or call attention to potential errors.  That’s true—to some extent.  But just like the autocorrect features found in word processing software, they cannot be relied upon entirely. We really must know which term is which by its correct spelling.

Now’s a good time to think about how we are preparing our students for their profession.  I want my healthcare providers to get it right.  So let’s make that happen!


Friday, July 26, 2013

Virginia Johnson Masters, sex research pioneer, dead at 88

On Wednesday of this week, just a few miles from my home in Missouri, Virginia Johnson Masters passed away at age 88.

Most of you are aware of the pioneering work in human sexual physiology she and her late ex-husband, William Masters, undertook at Washington University in St. Louis during the mid-20th century.  I briefly underscored that work in several of my textbooks:
"The study of human reproduction, and especially sexual function, has many cultural implications. So it is no wonder that American researchers William Masters and Virginia Johnson encountered a great deal of controversy during their decades of pioneering work in the field of human sex and reproduction. They were the first to study human sexual physiology in the laboratory. William Masters was a gynecologist (physician specializing in women's health) and Virginia Johnson was a psychologist. In 1966, their book Human Sexual Response clearly explained the physiology of sex for the first time. Besides making discoveries in the physiology of human sex and reproduction, they also developed therapies for treating sex-related conditions, and they trained therapists from around the world. In addition to the broad fields of biology, medicine, psychology, and the behavioral sciences, the pioneering work of Masters and Johnson paved the way for advances in such diverse and specialized areas of knowledge as comparative neuroscience and social dynamics. Today, there are many opportunities to apply knowledge of reproductive science in a variety of professions."

You may also recall my previous article Masters of Sex, in which I related some of my experiences with Johnson's late ex-husband and collaborator, Bill Masters.

With the Showtime network about to debut their new miniseries Masters of Sex, in which the character of Virginia Johnson plays a pivotal role, students will likely be bringing their curiosity about Masters and Johnson's work to their A&P courses.


Want to know more?

Virginia Johnson, Widely Published Collaborator in Sex Research, Dies at 88
  • By MARGALIT FOX
  • The New York Times Published: July 25, 2013
  • Detailed obituary
  • my-ap.us/13jaA4r

Masters of Sex
  • by Kevin Patton
  • The A&P Professor May 12, 2009
  • Brief article about Masters, Johnson, the recent book about them (on which the Showtime series is based), and Masters's unforgettable presentation at the HAPS Conference in 1995
  • my-ap.us/18HBhYx

Masters of Sex
  • by Thomas Maier
  • Basic Books April 13, 2009 432 p.
  • An amazing book about Masters and Johnson's story.  HIGHLY recommended reading for all A&P teachers!
  • amzn.to/12sLRQb




Related textbook content

  • Anatomy & Physiology 8th ed.  Chapters 34 and 35 my-ap.us/QZTbK1
  • Essentials of Anatomy & Physiology Chapters 24 and 25 my-ap.us/SCfNlj  
  • The Human Body in Health and Disease 6th ed. Chapter 23 (see bio on p. 610-611) my-ap.us/X71LJO 
  • Structure & Function of the Body 14th ed. Chapter 23 (see bio on p. 459) http://my-ap.us/10s50MH




Sunday, May 26, 2013

Student success strategies at HAPS 2013

If you happen to be here in Las Vegas at the 2013 Human Anatomy and Physiology Society (HAPS) Conference, then you may want to check out my workshop on Tuesday morning:

105

Helping A&P Students Succeed: 
Using Supplemental Courses and Workshops to Reinforce Concepts and Promote Learning Skills

LAS 221
Kevin Patton and Suzanne Hembrough
St. Charles Community College, Cottleville, MO 

Do your A&P students struggle with the whole process of learning? Do they seem ill prepared in their study skills and their knowledge of basic principles of biology? Explore case studies in which optional student workshops and short supplemental courses provide underprepared and unskilled students with knowledge and skills that make them better able to succeed in the A&P course and beyond. You will also receive free resources to help your own students succeed.

Thursday, May 23, 2013

Acupuncture and connective tissue

A recent article in TheScientist proposes a novel theory about how acupuncture may produce some of its therapeutic effects.

It turns out that when an acupuncture needle is inserted into the connective tissue under the skin and twisted, the needle becomes wound with connective fibers in much the same way as noodles enwrap a fork as it twirls.  This pulls on fibroblasts and causes local changes that may be transmitted throughout a large area of connective tissue and possibly produce therapeutic effects.

ATP released from stretched fibroblasts may also contribute to a pain-relieving effect.

An interesting new direction for further study.  And a good little story to weave into a discussion of fibrous connective tissues in our A&P course to illustrate that "it's not just glue."

Want to know more?

The Science of Stretch
  • H.M. Langevin
  • TheScientist published online 1 May 2013
  • Article summarizing the context and results of the research.  Includes nice graphic showing stretched fibers wrapped around a needle.
  • http://my-ap.us/16VQK5X


Biomechanical response to acupuncture needling in humans
  • Helene M. Langevin
  • Journal of Applied Physiology December 1, 2001 vol. 91 no. 6 2471-2478
  • The original research article.
  • http://my-ap.us/121Rxkp

Monday, February 25, 2013

Blood viscosity

Blood viscosity is a concept that is important in understanding blood flow.  It is, after all, one of the factors that affects peripheral resistance to blood flow.

One major factor influencing blood viscosity is hematocrit.  You may be interested in using the analogy of ketchup outlined a few months ago in my article for students Blood viscosity and peripheral resistance at theAPstudent.org

Recently, researchers also looked at the viscosity of the blood plasma alone (without the formed elements).  They found that blood plasma has unique characteristics of flow found only in non-Newtonian fluids, becoming less viscous with increasing pressure.  Again, just like ketchup. Plasma, unlike plain water, exhibits both viscous and elastic behaviors.

Researchers found in recent experiments that this characteristic of plasma may promote swirling where blood vessels diameters change—both at the beginning and end of a narrowed segment.  Thus, this could have an effect on formation of clots at stenoses or where a stent has been placed.

So, as you may have suspected all along, blood is not only thicker than water—it's weirder than water.

Want to know more?

  • Blood viscosity and peripheral resistance
    • Kevin Patton
    • The A&P Student 12 September 2012
    • [Analogy of ketchup flow for students.  Includes video.]
    • my-ap.us/XuR596
  • Blood Is Thicker Than Water – And Blood Plasma Is, Too
    • Science Daily Feb. 18, 2013
    • [Brief, plain-language article outlining the recent research.]
    • my-ap.us/YpGhas
  • Rheology of human blood plasma: Viscoelastic versus Newtonian behavior.
    • M. Brust, et al.
    • Phys. Rev. Lett, 110, 078305 (2013) DOI: 10.1103/PhysRevLett.110.078305
    • [Original journal article.  See photos from the experiments below.]
    • my-ap.us/15HVkle



Recording from one of the "drop-experiments": If blood plasma is placed between two plates and then they pulled apart, high-speed cameras show in conjunction with high-resolution microscope objectives that strands and droplets form. This demonstrates that plasma is elastic and viscous and does not behave like water.
Photo: Christof Schaefer, Phys. Rev. Lett. 110, 2013, 078305th Copyright (2013) by the American Physical Society

Plasma turbulence affects the blood. In one experiment, the researchers had plasma flow through a microfluidic constriction as in vasoconstriction. They showed turbulence at the end of the contraction, but also - as seen here in the pictures - sticking to its beginning. This turbulence is caused by the viscoelastic properties of blood plasma.
Photo: Mathias chest, Phys. Rev. Lett. 110, 2013, 078305th Copyright (2013) by the American Physical Society


Monday, February 11, 2013

Finger wrinkles

You know that dramatically wrinkling that occurs when your fingers and and toes get wet?

The classic explanation has been that such wrinkling is caused by osmosis.  But if you think about it, why does it occur only on the palmar and plantar skin surfaces?  My face doesn’t wrinkle when it’s wet.  Well, OK, my face is always a bit wrinkled—wet or not.

Some scientists are now thinking that this is not an osmotic effect but, instead, a nervous response to wetness.  According to this latest theory, such a response helps us avoid slipping and injuring ourselves in wet conditions.  It would also improve our ability to make and use tools under a variety of conditions.

Want to know more?

  • Pruney digits help people get a grip: Wrinkling may have evolved as an adaptation to wet conditions
    • Tanya Lewis 
    • Science News Web edition: January 9, 2013 Print edition: February 9, 2013; Vol.183 #3 (p. 11) 
    • [Brief article explaining the recent development in plain English.]
    • my-ap.us/XwFvGn

  • Water-induced finger wrinkles improve handling of wet objects.
    • K. Kareklas et al.
    • Biology Letters. Published online January 8, 2012.
    • [Journal article outlined proposed theory.]
    • my-ap.us/WbV5K9

  • For ancient hominids, thumbs up on precision grip.
    • B. Bower  
    • Science News, Vol. 177, May 8, p. 15. 
    • [Brief related article on evolution of human grip.]
    • my-ap.us/11zYCYt

  • Fingerprints filter the vibrations fingers feel
    • L. Sanders.
    • Science News, Vol. 175, February 28, p. 10
    • [Brief related article on sensory function of human epidermal friction ridges.]
    • my-ap.us/YksrEP

Monday, January 28, 2013

Academic integrity in A&P

About a year ago, I posted a brief item in my blog The A&P Student about academic honesty.  It succinctly describes what "academic integrity" is and explains clearly why it's in a student's own best interest to cultivate and practice academic integrity.

One of the most important points this post makes is this:
Research shows that people who practice dishonesty become more dishonest over time. Yikes.  Apparently, it's so easy to get in the habit of cheating that it soon becomes part of who you are and what you always do!  Don't let that happen to you . . . it will only cause misery.
This is an especially important lesson for those going into either the health professions or medical research.

After reading in What the Best College Teachers Do that professors recognized as "master teachers" have all abandoned fretting over futile attempts at building elaborate layers of defense against cheating for a more effective strategy: developing a culture of integrity in the course.  The old "honor system" really does work in a context of reasonable precautions!

Part of my effort to put this approach into practice is to have my students read my blog posting Why be honest? near the beginning of each semester.  I announce this assignment while relating the recurring nightmare that I think most of us share:
In my dream, I wake from unconsciousness as I'm being wheeled into an emergency room, strapped to a gurney. A health professional (for me it's a nurse) is covering my face with a mask as she (sometimes it's a he) says, "hey Dr. Patton, remember me?  I was the one you flunked in A&P for cheating.  I'm here to take care of you now."  I try to break free, but the straps hold tight.  I try to shout out, but the mask prevents it.  I wake up in a cold sweat.
I explain that this could be any of us.  Or our family or friends.  And ask them all to join me in creating a culture of integrity in our course.

Consider putting a link to Why be honest? in your course material.  Perhaps even make it required reading.  For example, my friend Gary Heisermann includes a link and related question about the content in his first homework assignment, which reviews and emphasizes various important policies in his A&P course. I include it in each course syllabus.


Want to know more?
  • Why be honest?
    • Kevin Patton
    • The A&P Student 5 Jan 12
    • [Provide this link to your students in your syllabus or online course resources.]
    • my-ap.us/zHHd7H

  • What the Best College Teachers Do
    • Ken Bain
    • Harvard University Press April 30, 2004
    • [In stories both humorous and touching, Bain describes examples of ingenuity and compassion, of students' discoveries of new ideas and the depth of their own potential. What the Best College Teachers Do is a treasure trove of insight and inspiration for first-year teachers and seasoned educators. ]
    • amzn.to/YhiYnu

  • The "Truth" About Why We Lie, Cheat, And Steal
    • NPR staff
    • NPR.org 4 June 2012
    • [Interview with Dan Areily, author of The Honest Truth about Dishonesty, and current research on dishonesty.]
    • my-ap.us/YhjJwD

  • The (Honest) Truth About Dishonesty
    • Dan Ariely
    • Harper June 5, 2012
    • [The New York Times bestselling author of Predictably Irrational and The Upside of Irrationality returns with thought-provoking work to challenge our preconceptions about dishonesty and urge us to take an honest look at ourselves.]
    • amzn.to/UctZ5G


Image by Hariadhi


Monday, January 21, 2013

Start A&P 2 with a Final Exam

I always start my A&P 2 with a final exam. WHAT?! Yep, that's right. I start with a FINAL exam!

It's a version of the final exam that I give my A&P 1 students. I warn them in A&P 1 that they need to retain all these concepts . . . they'll surely see them again. Then when they return from their break to start A&P 2, WHAM! Right in the face.

I call this exam that starts off my A&P 2 course "Test Zero." It's before the first regular test of A&P 2, Test One, so that makes sense. But it does "count" toward their course grade. It's a randomized, online test that they can do up to three times (each attempt is a different version of the exam).

Test Zero reviews the entire A&P 1 course--including the hard parts. It helps them brush up on what I want them to know to be successful in their A&P 2 course. And later courses.

It's also another opportunity for them to practice. As we all know, if we don't use it, we'll lose it.

I've done this for many years now and it works wonderfully. I can really see a difference each time we encounter an "old" idea from A&P 1.

Want to know more?

  • Teaching as Testing.
    • Kevin Patton
    • The Electronic Professor 27 Feb 2009
    • [Article outlining my use of randomized online testing as a mechanism of needed practice. Includes links to a full video presentation.]
    • my-ap.us/p3rM6B


  • Practice. Practice. Practice.
    • Kevin Patton
    • Lion Tamers Guide to Teaching 3 December 2010
    • [Article on the role of practice in teaching and learning, using the analogy of taming lions.]
    • my-ap.us/WjNHLn