Anatomical MOOC: The shoulder bone’s connected to what again?

Course: Going Out on a Limb: Anatomy of the Upper Limb
School: Penn via edX
Instructors: Dr. James S. White
Quote:
Anatomy lab isn’t just for first year medical students anymore. With this online anatomy course, anyone can learn about the upper limb, without the cadaver.
…We’ll start with basic human anatomical terminology and apply that knowledge to examining the bones of the upper limb and how they articulate at joints. You will also learn about the muscles that produce movement at those joints in addition to the innervation and blood supply of the upper limb.

You’d think anatomy would be incredibly boring: “The finger bone’s connected to the hand bone, The hand bone’s connected to the arm bone…” (which, by the way, is anatomically wrong) without the music. Sure, there was a lot of that, but I found it fascinating anyway. Then again, I’m weird. And I really, really like medical stuff. Which, of course, is why I took it, since I have absolutely no reason to learn anatomy. Most of the students were in, or aspiring to, health care or fitness fields (and boy, did they know their stuff; lots of information on the discussion boards), and that’s at whom the course was aimed. In fact, Dr. White indicated it’s pretty much one section of first-year medical school anatomy (minus the cadavers).

Medical school students are, of course, expected to have all of this memorized. That’s why medical students are in their 20s, not their 60s; it’d take me a year to memorize all this, and then I’d lose it since it’s not information I would use on a regular basis (or ever again, really). But while there were plenty of charts of muscles, actions, origins and attachments, and innervations, and hundreds of diagrams from the anatomical planes and position to the detailed routes of nerves and tendons, there were also some interesting tidbits that were more retainable for even the likes of me.

Like for instance, the brachial plexus mixes up all the nerves from the cervical vertebrae so that every arm muscle is innervated by more than one spinal cord segment, which allows function to continue in spite of severe injury to a particular nerve. And that’s also why, when my cervical disks started collapsing one after the other, my arms often hurt in the same place.

Remember how we all learned in junior high that the shoulder’s a ball and socket joint? Well, that’s true, except the socket is extremely shallow, so the whole shoulder is held together by tendons and muscles, which is why some people (like my ex-husband) dislocate a shoulder if they sneeze too hard. And a wristwatch is really a forearm watch, because the wrist bones are in what most people consider the hand. Rotator cuff injuries, carpal tunnel syndrome, all sorts of fun things were all splayed out for us on multicolor slides.

While the quizzes did have a lot of “what is this structure” questions, there were also some items that required putting together the anatomy and working with it. Such as: Why is a fall on an outstretched hand more likely to injure the scaphoid or lunate bones than to the triquetrum? It has nothing to do with the wrist bones; it’s the cartilage on the end of the ulna that absorbs some of the shock to the triquetrum. And, by the way, I love the word triquetrum, it’s my favorite bone. Here’s another one: A woman has upper limb weakness after surgery, and is unable to protract her scapula. What muscle has most likely been affected? And my favorite question(s) of the entire course:

To bring the palm of the hand from anatomic position to facing posteriorly using the shoulder joint, one would have to do which of the following actions?
– Medial rotation – correct
– Lateral rotation
– Pronation
– Supination
 
To bring the palm of the hand from anatomic position to facing posteriorly using the elbow and wrist radioulnar joints, one would have to do which of the following actions?
– Medial rotation
– Lateral rotation
– Pronation – correct
– Supination

See, you can turn your palm backwards either by moving your whole arm at the shoulder, or by flipping your radius over the stationary ulna, and those are completely different actions using completely different muscles. Cool! No? Well, I had fun. And the best part is: Thoracic anatomy is in the works. I’m really looking forward to that.

Like I said, I’m weird.

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