Monday, September 15, 2014

Learning Tissues Bird by Bird

What?!  Bird by bird?

Yep—that's the best way to begin learning how to distinguish the various tissue types of the body.

The bird-by-bird approach to learning anatomy is based on two major concepts, described here.

Chunk the List

The first was described by author Anne Lamott in her book Bird by Bird: Some Instructions on Writing and Life:
"Thirty years ago my older brother, who was ten years old at the time, was trying to get a report on birds written that he'd had three months to write. It was due the next day. We were out at our family cabin in Bolinas, and he was at the kitchen table close to tears, surrounded by binder paper and pencils and unopened books on birds, immobilized by the hugeness of the task ahead. Then my father sat down beside him, put his arm around my  brother's shoulder, and said, 'Bird by bird, buddy.  Just take it bird by bird.'"
Wow—doesn't that sound just like the feeling you have when you are given a list of human tissues to learn in your A&P course?  With crazy names like nonkeratinized stratified squamous epithelium, specimens that look like the abstract art exhibit at the art museum, and an insanely short time frame to master them all, of course it feels overwhelming.

Really, that's the best way to tackle the tissues.  Just get started!  And take them one by one, rather than thinking about the whole long list of them facing you.  You'll find that by chunking the list this way, it's not so paralyzing.  It sounds overly simple—perhaps even a bit silly—but it really works!

Focus on Unique Characteristics

A while back, I wrote a post called Trouble with Tissues? in which I briefly described a method for learning tissues based on how birders learn how to tell one bird from another when out birdwatching:

The introduction to my Field Guide to the Body at the Lion Den website compares studying tissues to what birders do when they identify wildlife in the field. Take a look at that brief analogy, including examples of how to apply it to histology, for helpful tips on making this topic easier. If you're using any of my lab manuals in your A&P course, you can apply this technique directly by looking at the Landmark Characteristics boxes scattered throughout the tissue exercises.

To summarize this method, you simply look at what makes each tissue different from other tissues just as you would when learning the many different types of sparrows live in the state park:

  • Field marks—physical characteristics that distinguish one type from another.  All sparrows are LBJs (little brown jobs), but each species has a unique characteristic such as a beak color or streak on the cheek that sets it apart from the others.  Likewise, each tissue type has one or more physical characteristics—such as cell shape or fiber type or cell arrangement—that make it stand out from all other similar tissues.

  • Range—if I look out my window and see a penguin, I know I need my eyes examined.  Because I live in Missouri, where penguins live in only in zoos.  So I can identify birds in part by which birds live in or visit my region.  Bird guides list ranges for this reason—to help you figure out which bird the one in your yard could be.  If you learn the locations of tissues, that helps you figure out where to look for them.  For example, look for most epithelial tissues on surfaces, look for cardiac muscle in the heart.  If you are looking at a tissue sample from the arm, then don't expect that muscle tissue to be cardiac muscle—it's instead likely to be skeletal muscle tissue,

  • Habitat—Besides knowing which region a bird is likely to be found, it also helps to know what kind of habitat it prefers.  Look for forest birds in the forest and look for shore birds, well, along the shore.  With tissues, if you know that if you are looking for irregular fibrous tissue, look under epithelium—there's always some there.

  • Behavior—Behavior is function.  When identifying birds, it helps to know how they fly (do they soar like vultures or hover like hummingbirds?).  When identifying tissues, it helps to know their functions.  If you know that fibrous connective tissues are often supportive in function, that will help you find them.  If you know that smooth muscle tissue compresses the hollow part of hollow organs, you know where to find them—within the walls of hollow organs such as digestive organs.

Not Just for Tissues

This method also works well for learning bones and bone features, muscles of the body, nerves, digestive organs, and more—any of the "birds" of the body!

Want to know more?

Trouble with Tissues?

  • Kevin Patton.  The A&P Student. 28 September 2010.
  • Outlines tips for studying tissues in the A&P course.

Field Guide to the Human Body

  • Kevin Patton. Lion Den. Accessed 7 September 2014.
  • From my study tips website, this page introduces the "birding" analogy to studying human structures.

Bird by Bird: Some Instructions on Writing and Life

  • Anne Lamott. Anchor. First published 1 January 1994.
  • Great book.  Great author. That is all.

Survival Guide for Anatomy & Physiology

  • Kevin Patton. Elsevier. Oct 18, 2013.
  • Tips and techniques for studying A&P, including tissues, mentions the birding analogy.

Monday, September 8, 2014

Echocardiogram Visualizes Heart Function

One of the best ways to learn about the heart is to watch it work.  But how can you do that, considering that if you open up the thoracic cavity, then slice open the heart, you'd break it?

But biomedical science has shown us another way to see the parts of the heart and how they work.  It's called echocardiography.

It's a technique that uses the same technology as the sonograms you've seen of fetuses inside their mother's belly.  Basically, it bounces sound waves through the body and makes an image of whatever bounces back (an echo). But echocardiography is adapted specifically to the heart and its function.

Want to see echocardiography in action and better visualize heart function? Try watching this video.

Video source:

Image credit: Patrick J. Lynch, medical illustrator

Monday, September 1, 2014

DNA Replication in 3D Motion

When trying to get a grasp DNA replication—the copying of DNA prior to cell division—it often helps to see what's going.

The static diagrams accompanied by written narrative of the story in most textbooks are good places to start figuring out DNA replication—but it really helps if you can watch it all unfold in 3-dimensional motion.

I've found a video that really helps you understand the process.

A bit of advice before you watch it:
  1. You ought to read through the DNA replication story in your textbook and look at the diagrams there.  If you watch this cold, it may not help you as much.
  2. The details of how the DNA-replicating enzymes work and what they look like is not the important part of the story.  The important part is just seeing how it all works as a biochemical "machine."
  3. I recommend watching the video more than once.  You'll "get it" better that way, because it goes at a pretty fast clip.
  4. Eating popcorn while watching this movie is totally up to you!

Video source:

Image credit: madprime