P4 PHYSIOLOGY LAB Flashcards
Electromyography EMG
a recording of electrical activity
of the muscle is known as
Electromyography (EMG)
used as an non-invasive EMG
Surface electrodes
does not introduce any electrical stimulation instead it records the intrinsic electric activity of skeletal muscle fibers.
needle EMG
incase of increased insertional activity it can be due to
- muscle inflammation
- denervated muscle fibres
incase of decreased insertional activity it can be due to
Fibrosis
Response of the muscle fibers to needle electrode insertion is known as
insertional activity
the shown EMG is seen in case of
denervated muscle
the shown EMG is seen in case of
myopathy
in myopathic diseases number of what cells is affected
Number of muscle fibers in each MU will be decreased
what is the hallmark of myopathy
early recruitment
low number of motor unit is seen in
Partially denervated muscle
The order of MU recruitment depends on
- size of motor neuron
- threshold of recruitment
- type of motor units
- synaptic density
rapid flickering / vermicular twitching movements due to contraction of bundle of muscle fibers are known as
fasciculations
contraction of individual muscle fiber is known as
Fibrillation
fibrillation indicate
neuropathy / myopathy
Identify he MUP component pointed by the arrow
Amplitude
Identify he MUP component pointed by the arrow & its significance
- rise time
-Reflects the distance between the recording electrode and the muscle fibers of the motor unit.
Identify he MUP component pointed by the arrow & its significance
- duration
-Indicates the synchrony among various fibers of a motor unit
