Lab 2: Human Muscle Physiology Flashcards
what is an EMG?
Electromyography; it is a recording of electrical activity (electricity) conducted on muscles
what is RMS?
Root Mean Square; measures variability; the more electrical activity on a muscle cell the greater the contractile force
as EMG increases, what also increases?
force
what other factors can muddy the relationship between electricity and force?
tendons; they are stretchy
how do we increase electrical activity?
increase frequency of Action Potentials
what does frequency mean?
the number of Action Potentials per second
what is another name for a muscle cell?
muscle fiber
what is summation?
increase in muscle force due to increase of frequency of Action Potentials
what is a motor unit?
one neuron and all of the muscle fibers it innervates
what is recruitment?
the addition of more motor units
what happens when you train/workout?
size of cells change
what is hypertrophy?
cells getting bigger/increasing size
what are myosin and actin?
contractile proteins allowing cell to be more forceful
what is hyperplasia?
increase in number of cells (when training, your cells are getting bigger but they aren’t increasing in number)
after 1 week of training you’re stronger but muscles still haven’t changed size/shape. how does this happen?
recruitment= coordination; the brain and nervous system help motor units become synchronized: neuromuscular coordination; then both hypertrophy and neuromuscular coordination both start working together
