But the exact amount really doesn't matter, it just seems that as we descended down through the layers of the skin, we encountered the muscles that move us.
Betty, laying prone, was in the posterior view (we were looking at her back) showed us her muscles that moved her head, arms and held her up right.
What does a muscle look like, well, not to put you off, but sorta like roast beef. Muscles are stringy, made of protein fibers wrapped around by fascia and put together just like strings form ropes. So, muscle structure gives you a clue of what they do.
For example, the trapezius muscle
shown here (Wikipedia is the source) is named for its unique shape. Any high school student can tell you what a trapezoid is and hence its name. This muscle quite big, moves the spine, moves your scapula, helps you throw a ball, lifts your head after looking down (extends the neck) are some of its actions.Muscle motions are called actions, the places they connect to bones are called insertion and origin. The insertion is the bone that does not move when the muscle contracts and the insertion is the bone it moves.
The main job of muscles is to move your bones, creating motion. The other jobs muscle perform are keeping you warm (shivering for example), movement of materials inside your body (food in the gut for example) and posture-keeping standing erect.
All muscles have nerves (called innervation) and a rich blood supply. Muscle cells have many mitochondria as these organs need lots of energy.
In Betty's body are three kinds of muscles, the skeletal muscles attached to bones, the smooth muscles of the organs and cardiac muscles of the heart.
Betty's trapezius was rather large, but it was a thin muscle, meaning she didn't do a lot of lifting. A person who does a lot of shoulder shrugs with weights will develop a "web" appearance in the neck, especially if you look at them from the front.
Betty's muscles were not easy to separate. One goal of our class was to "clean" (remove all fat and fascia) and separate the muscles from each other. Some muscles were easy to separate, others not so well.
While we didn't dissect all 640 muscles, it felt like it by the end of the term. To be honest, I was looking forward to seeing something else beside muscles after a few weeks of nothing but, muscle this, muscle that.
