Explain the source of signals detected by EMG electrodes. What is actually measured. Based on your answer, explain why an EMG recording would increase with increasing strength of the clench. If 2 clenches produced the exact same force of contraction, would the EMG recording also have to be exactly the same? Why or why not?

Explain the source of signals detected by EMG electrodes. What is actually measured. Based on your answer, explain why an EMG recording would increase with increasing strength of the clench. If 2 clenches produced the exact same force of contraction, would the EMG recording also have to be exactly the same? Why or why not?

Biomedical Instrumentation Systems

1st Edition

ISBN:9781133478294

Author:Chatterjee

Publisher:Chatterjee

Chapter7: Instrumentation In Diagnostic Cardiology

Section: Chapter Questions

Problem 7P

See similar textbooks

Similar questions

The force of contraction can be changed by: can choose more than on e Group of answer choices - muscarinic ACh receptors. Activation of the receptors leads to decreased Ca2+ entry and increased K+ entry in ventricles. - Beta2 adrenergic receptors. Increasing cAMP leads to increases in PKA, which increases sarcoplasmic calcium by opening VG Ca+ channels for a longer time, opening SR Ca2+ channels, and increasing the rate of Ca2+ removed by SERCA pumps. - Beta1 adrenergic receptors. Increasing cAMP leads to increases in PKA, which increases sarcoplasmic calcium by opening VG Ca+ channels for a longer time, opening SR Ca2+ channels, and increasing the rate of Ca2+ removed by SERCA pumps. - Not by the parasympathetic NS. (at least, not the ventricles).
In your own words, explain how the EMG trace changed when you added weights to your arm?Based on the data you collected what can you infer is happening to the muscles as weight is added?
Caffeine lowers the heart rate by increasing rates of depolarization at the SA node True False Nicotine raises the heart rate because it stimulates the activity of the sympathetic neurons in medulla oblongata True False The Frank-Starling Law of the Heart states that the force of heart contraction is directly proportional to the initial length of the muscle fiber, within optimal limits of length True False If the sarcomeres stretched beyond the optimal length, the force of contraction would go down, but that can potentially happen only during open heart surgery when the heart is not constrained by the pericardium, lungs, ribs and diaphragm. True False It is the Na+ channel-driven spontaneous depolarization that is affected by sympathetic and parasympathetic inputs to speed up or slow down the firing rate of the SA node and other conductive cells. True False
How does varying the frequency effect contraction force? Which interval caused the greatest contraction?
These figures show that: Group of answer choices eccentric contractions place a greater demand on the cardiovascular and nervous systems compared to concentric contractions concentric contractions are easier to perform than eccentric contractions concentric contractions require more oxygen and more EMG than eccentric contractions eccentric contractions use less oxygen but more EMG than concentric contractions
The following are oscilloscope tracings displaying the contractile activity of an isolated frog heart. Tracing A was taken while the heart was suspended in 23°C standard Ringer's solution. What was most likely changed to obtain tracing B? 2 4 21 Time (msec) 5 Time (msec) F 1161 TA 8 CO 10 O The Ringer's solution was cooled to 5°C Acetylcholine was added to the Ringer's solution A cholinergic agonist was added to the Ringer's solution O An adrenergic antagonist was added to the Ringer's solution Epinephrine was added to the Ringer's solution
The EMG is a recording of: * The action potentials of the motor nerves supplying the muscle fibers. The action potentials of the innervated muscle fibers. The contractions of the innervated muscle fibers O The action potential of the pacemaker cells O The electrical activity in the sarcoplasmic reticulum
Answer the following showing your work: a) If the attenuation coefficient of the heart muscle anm the distance at which the signal amplitude of a 2-MHz ultrasound beam will be reduced by half traveling through heart muscle. b) You have two transducers available, a 25-MHz transducer and a 3-MHz transducer. Which transducer should you use to perform an echocardiogram, and why (show your work)? = 0.185 (cm MHz)-, calculate
Put the steps for running an EMG to study fatigue in the correct order. At regular intervals, measure the applied force by looking at the blue signal. ts Increase the clench force to maximum eBook eferences Start recording the EMG signal. 3 At every interval, count the number of active motor units, repeat until the applied force drops to 50% of its initial value Mc Graw Hill ype here to search
A 65-year old man with heart failure is unable to climb a flight of stairs without experiencing dyspnea. After several years of therapy with carvedilol, captopril and furosemide, the therapeutic plan probably needs to change now. You empirically add digoxin to improve cardiac muscle contractility. Within 4 week he has a marked improvement in his symptoms. Which of the following best describes the main cellular action of digoxin that accounts for its ability to improve his cardiovascular function? Activates beta1-adrenergic receptors Facilitates GTP binding to specific proteins Increases mitochondrial calcium (Ca++) release Inhibits sarcolemmal Na/K-ATP-ase
1. Explain the source of the signals detected by the EMG electrodes. 2. Describe the role of Ca2+, Na+, and K+ in muscle contraction. 3. Explain “motor unit recruitment” in your own words and relate that to why EMG values increase with greater force
Which of the following is a correct sequence (in chronological order of occurrence) within excitation-contraction coupling? a. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter binds to receptors in the post-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft b. Neurotransmitter binds to receptors in the post-synaptic membrane, Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft c. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft, Neurotransmitter binds to receptors in the post-synaptic membrane