Category Archives: Anatomy & Physiology

Taking a break from Covid-related news, I came across a 2018 article in the ACSM Health and Fitness Journal extolling our marvelous (and maybe underappreciated) eyes.  Certainly those with impaired vision do not take their eyes for granted.  My father in his 80’s suffered a mini-stroke and woke up effectively blind.  He lived another 10 years but his enthusiasm for life waned as he was a voracious reader.  Many others have had sight complications earlier in life or even at birth.  But for most of us, we rely on our eyes without thinking a whole lot about them. So, James Peterson’s article “Ten Nice-to-Know Facts About the Eyes” caught my eye, literally, and I thought my blog readers might find this interesting.  So a bit rephrased, here are his 10: Our eyes are nearly full size at birth.  The rest of the body grows around them!  For those with normal vision about 80% of what we learn and remember is due to sight.   After the brain, eyes are the most complex and powerful organ in our bodies.  With them we distinguish shapes, colors, depth, and adapt to changes in light.  The tiny muscles controlling the eyes don’t get time … Continue reading →

I’ve been reading Anatomy for Runners by Jay Dicharry (Skyhorse Publishing, 2012).  It’s conversationally written.  You can picture yourself in a seminar setting with Jay presenting PowerPoints, cracking jokes, and noting anecdotal evidence.  The book covers the entire gamut of running, with a focus on injury prevention.  It’s pretty opinionated but includes an extensive reference list from which he draws.  Dicharry is a seasoned clinician and has no doubt seen many versions of all the injuries about which he writes.  He discusses in depth a concept worth expanding on — pliability, which Webster defines as “flexible, supple, yielding.”   Dicharry uses it in the context of muscle function. We all know what it feels like to be tight and stiff.  This, often in spite of regular stretching and taking it easy between hard efforts.   As Dicharry explains, the tension in muscles is not the same up and down the line.  And does not dissipate evenly.  Let’s look at hamstrings, the oft strained muscle in runners.  The biceps femoris attaches both at the hip and below the knee.  With insertion points crossing two joints, the tension varies along the hamstring.  For example, when running, one end of the biceps femoris contracts concentrically … Continue reading →

Football season is about to begin.  You may recall, when a player’s knee hits the ground and he’s touched by a defender, play is called dead.  Often the quarterback “takes a knee” to stop the clock.  But this post is not about football!  Rather a look at our marvelous and incredible knees, the mid-point of our lower extremities — the runner’s drive train.  Since knees are the most common site of running injuries, it’s worth reviewing how they function.  Pictured below, the knee is the largest joint in the body.  The knee actually has three joints:  the tibiofemoral (largest, lying between our thigh and lower leg and generally thought of as the knee joint), the patellofemoral (kneecap), and the tibiofibular (below the kneecap and not directly part of the knee movement.)  I’ll focus first on the tibiofemoral joint here, which functions as a hinge. Unlike the hip joint, where there is significant bony structure, most of the knee’s stability comes from soft tissue – ligaments, tendons, muscles, cartilage, menisci, bursa, and fat pads.  This constitution allows for significant range of motion – for example, we can bend our knee to touch our butt with our foot. When looking at knee … Continue reading →

Imagine this: if each cell in our body was represented by a one-meter step, we would have to circle the earth over one million times to account for all our cells. It seems absurd, but it’s true.   We are each composed of between 50 and 100 trillion cells! As I continue to report on my study of Human Anatomy and Physiology by Elaine Marieb, I move from chemistry to structural components. Cell theory was developed in the late 1800s and is based on four core elements: The cell is the basic unit of living organisms, Organisms depend on both individual and combined activities of its cells, The activities of cells are dictated by their shape and number of structures they contain, and Cells arise from other cells. Restated, our 50+ trillion cells are the body’s building blocks, they don’t stand alone, they look different and do different things, and they’re self perpetuating. Cells have membranes that allow solutions to move in or out and have specialized organelles, such as mitochondria, which provide the energy for all we do. The nucleus is where our DNA (what makes us us!) lives and cell division happens, without which we would literally be one … Continue reading →

I recently retired from a career in finance and accounting and moved back to Vermont. I have been doing personal training and run coaching on a very part-time basis but now have the time to be a full-fledged exercise science professional. To facilitate this, I’m looking at a course in exercise physiology offered at UVM next semester. In case this proves a viable option, I am self-studying the prerequisite, Human Anatomy and Physiology by Elaine Marieb, a yearlong course covering the gamut of all that happens inside us. I figured this would be a cursory overview, which I could skim and be ready for class in January. Wrong! Right off the bat this book went into fascinating detail of how our bodies work. Fortunately, many of the terms were familiar — graduate studies in food science and nutrition years ago had not permanently eluded me. But the context is quite different. Before I was trying to memorize things without a use in mind. Now, I look at this from the perspective of running and coaching.   It’s like walking into a previously dark room now full of color and bright lights! Take for example the section on “Factors Influencing the Rate … Continue reading →

Tom Derderian, coach of the Greater Boston Track Club and fellow 60+ runner with a 2:19 marathon PR, summed it up pretty well when he said after a USATF-New England Grand Prix race last year, “I know what to do, I just can’t do it” Granted, Tom’s standards are high. However reconciling memories of past times with current reality proves a challenge as we age. When Father (or Mother) Time starts visiting varies significantly among runners. Debilitating injuries interfere with our mechanics. Maladies such as knee arthritis or worn cartilage make sustained training problematic. And the longer we have run, the more likely overall wear and tear. There are as many training plans and life circumstances as there are runners. But the questions remain: Why do we slow down? And what can we do to delay the onset? To answer the first question, it’s critical to probe what is really going on in our bodies as we age. First, muscle strength is critical to performance. And assuming no change in training regimen other than aging, a study of active men aged 15 to 83 by Taylor Lexell showed both a change from Type II (fast twitch) to Type I muscle … Continue reading →