2. EEG, ECG and EMG Flashcards
(18 cards)
What is EEG?
Measures brain electrical activity. Reflects averaged action potentials from many neurones.
What is EEG key for diagnosing? (3)
Epilepsy, sleep disorders, brain damage.
EEG amplitude and frequency characteristics.
Amplitude ~ 100V
Frequency: 0.5Hz - 100Hz
Brain wave types and associated sleeping patterns.
Gamma, beta, alpha, theta, delta. (See revision sheet.)
Pros of EEG - 2
Noninvasive, useful for detecting large scale activity
Cons for EEG
poor spatial resolution; cannot read single neurones
What is an ECG?
Measures heart’s electrical activity using surface electrodes
What 3 things can an ECG reveal?
Heart rythm, conduction abnormalities, heart attacks.
Charactersitics of ECG.
Amplitude 1-5mV
Frequency 0.05Hz - 100Hz
ECG waveform components
See formula sheet.
What are 2 explamles of the uses of an ECG?
arrhythmia detection, heart attacks
2 pros and 1 con to ECG usage?
Pros: high diagnostic accuracy, widely used
Con: Doesn’t assess blood flow or vessel blockage.
What is an EMG? How is it used?
Records muscle activity and motor neurone function. surface electrodes or nedle electrodes
What are two diagnosis examples and one use?
Diagnosis: neuromuscular disorders, motor control disease
Use - prosethic control
EMG characteristics
Amplitude: 1-10mV
Frequency: 20Hz - 2000Hz
Name 3 muscle system properties.
40% of body mass
excitable—respond to stimuli
contractile - generate tension
2 pros of EMG
- good for distinguishing nerve vs muscle disorders
- Can be non-invasive
2 cons of EMG
- semiquantitative
- Doesn’t indicate force of contraction directly
