Electromyography Flashcards
What is an EMG
Electromyography, a recording of the action potentials occurring in skeletal muscle fibres
What is Extra-cellular recording
Both electrodes are outside the muscle fibres and the emf is recorded between 2 locations
What is an ECG
Electrocardiogram, recording AP from the heart. Electrodes on the limbs or chest
What is an EEG
Electroencephalogram, recording AP from the brain. Electrodes on the scalp
Describe intracellular recording
One electrode is inside the cell, the other outside. Voltage difference between inside and outside the cell is measured
What is intracellular recording done usually on
Cultured cells with a fine electrode
Describe extracellular recording
Both electrodes outside the muscle fibres, measure the voltage between 2 sites outside the fibres
Give the constituents of the Thenar group
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Adductor pollicis
Define twitch
A force created in response to 1 stimulus. Action potential created, showing a little “blip” in the force that generates and dies out much slower
Define summation
Applying a stimulus very quickly causes the force to increase as it cannot dissipate before the next action potential
Define tetanus
Fused tetanic contraction. A contraction whereby individual twitches cannot be seen.
Sustained contraction following a series of stimuli (Building of contraction events)
What nerve runs behind the humerus
Ulna
What is the difference in force when stimulation is artificially applied and when voluntarily applied
No difference, there is a max. force generated
What is CT scan
cross-sectional imaging using X-rays
Used for stroke (shows blood)
What is a MRI
cross-sectional imaging using radio waves and strong magnetic fields
Good for visualising soft tissue
Used for tumour
