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Physiology Lessons for use with the Biopac Student Lab

Richard Pflanzer, Ph.D. Associate Professor Emeritus Indiana School of Medicine Purdue University School of Medicine

William McMullen Vice President BIOPAC Systems, Inc.

BIOPAC® Systems, Inc. 42 Aero Camino, Goleta, CA 93117 (805) 685-0066, Fax (805) 685-0067 [email protected] www.biopac.com

DOC 5 – BSL3 Answers 09112009  BIOPAC Systems, Inc.

DATA REPORT ANSWER GUIDE Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5 Lesson 6 Lesson 7 Lesson 8 Lesson 9 Lesson 10 Lesson 11 Lesson 12 Lesson 13 Lesson 14 Lesson 15 Lesson 16 Lesson 17 Lesson 18 Lesson 20

EMG I EMG II EEG I EEG II ECG I ECG II ECG & Pulse Respiratory I EDA & Polygraph EOG I Reaction Time Pulmonary Function I Pulmonary Function II Biofeedback Aerobic Exercise Physiology Blood Pressure Heart Sounds Metabolic Rate Spinal Cord Reflexes

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Copyright Information in this document is subject to change without notice and does not represent a commitment on the part of BIOPAC Systems, Inc. This manual and the software it describes are copyrighted with all rights reserved. Under copyright laws, this manual or the software may not be copied, in whole or part, without the written consent of BIOPAC Systems, Inc., except in the normal use of the software or to make a backup copy. The same proprietary and copyright notices must be affixed to any permitted copies as were affixed to the original. This exception does not allow copies to be made for others, whether or not sold, but all of the material purchased (with all backup copies) may be sold, given, or loaned to another person. Under the law, copying includes translating into another language or format. Biopac Student Lab Lessons, including all text and graphics, are © BIOPAC Systems, Inc., with all rights reserved.

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Biopac Student Lab

Warranty BIOPAC Systems, Inc. warrants its hardware pro-ducts against defects in materials and workmanship for a period of 12 months from the date of purchase. If BIOPAC Systems, Inc. receives notice of such defects during the warranty period, it will, at its option, repair or replace the hardware products that prove to be defective. This warranty applies only if your BIOPAC Systems, Inc. product fails to function properly under normal use and within the manufacturer’s specifications. This warranty does not apply if, in the sole opinion of BIOPAC Systems, Inc., your BIOPAC Systems, Inc. product has been damaged by accident, misuse, neglect, improper packing, shipping, modification, or servicing by other than BIOPAC Systems, Inc. Any returns should be supported by a Return Mail Authorization (RMA) number issued by BIOPAC Systems, Inc. BIOPAC Systems, Inc. reserves the right to refuse delivery of any shipment containing any shipping carton without the RMA number(s) displayed on the outside. The Buyer shall prepay transportation charges to the site designated by BIOPAC Systems, Inc. BIOPAC Systems, Inc. makes no warranty or representation, either expressed or implied, with respect to this software, its quality, performance, merchantability, or fitness for a particular purpose. As a result, this software is sold “as is” and you, the Buyer, are assuming the entire risk as to its quality and performance. In no event will BIOPAC Systems, Inc. be liable for direct, indirect, special, incidental, or consequential damages resulting from any defect in the software or its documentation, even if advised of the possibility of such damages, or for damage of any equipment connected to a BIOPAC Systems, Inc. product. Trademarks Biopac Student Lab is a trademark of BIOPAC Systems, Inc. Apple and Macintosh are trademarks of Apple Computer, Inc. Windows is a trademark of Microsoft Corp. This document was created with Microsoft Word for Windows, Adobe Photoshop, Corel Draw 7.0. Mainstay Capture, and JASC, Inc. JasCapture. 08.20.09–3.7.6; 09.11.09—L15.

Lesson 1

ELECTROMYOGRAPHY I—Standard and Integrated EMG

I. Data and Calculations A. EMG Measurements Cluster #

Min

Forearm 1 (Dominant) Max P-P Mean

Min

Max

[3 min]

[3 max]

[3 min]

[3 max]

[3 p-p]

[40 mean]

Forearm 2 P-P Mean [3 p-p]

[40 mean]

1 2 3 4 The mean measurements will be dependent on the amount of time for each cluster. The area measurements should be for 1-sec midsection.

B. Use the mean measurement from the table above to compute the percentage increase in EMG activity recorded between the weakest clench and the strongest clench of Forearm 1. Calculation:

Answer:

II. QUESTIONS

%

DATA REPORT ANSWER GUIDE

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C. Does there appear to be any difference in tonus between the two forearm clench muscles? _____ Yes _____ No Would you expect to see a difference? Does subject’s sex influence your expectations? Explain. Because tonus is influenced by many individual factors, tonus could differ between forearms if an individual uses one arm more than the other arm or if the muscle fibers were larger in one arm than the other arm. Tonus is indirectly influenced by gender because muscle fiber size is influenced by testosterone levels, which vary between males and females.

D. Compare the mean measurement for the right and left maximum clench EMG cluster. Are they the same or different? _____ Same

_____ Different

Which one suggests the greater clench strength? _____ Right _____ Left _____ Neither Explain. The larger measurement suggests greater clench strength because the strength of the muscle is dependent on the size (cross-sectional area) of the muscle fibers. The greater the size of the muscle fibers, the greater the EMG.

E. What factors in addition to sex contribute to observed differences in clench strength? Clench strength can be influenced by resistance training of high-intensity, quick movements practiced in short bouts. This type of anaerobic exercise causes muscle enlargement due to synthesis of actin and myosin more cross-bridges formedincreased contractile strength. Other factors affecting clench strength are recovery from fatigue and availability of energy stores.

F. Explain the source of signals detected by the EMG electrodes. Basically, signals detected by the EMG electrodes come from the electrical activity of the muscle. Depending on lecture material—the AP propagation of the sarcolemma. Other activities besides those of the muscle contribute a minor portion of the recording.

G. What does the term “motor unit recruitment” mean? Motor unit recruitment is the activation of increasing numbers of motor units in a muscle to achieve graded levels of contractile strength.

H. Define skeletal muscle tonus. Skeletal muscle tonus is the baseline activity levels of a muscle.

I. Define electromyography. Electromyography is the study of recordings of muscle activity.

End of Lesson 1 Data Report Answer Guide

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Biopac Student Lab

Lesson 2 I.

ELECTROMYOGRAPHY II—Motor unit recruitment and Fatigue

Data and Calculations

Motor Unit Recruitment

A. Complete Table 2.1 using Segment 1 data. Note: You may not need nine peaks to reach max.

Peak #

Targeted Force

1

10

2

20

3

30

4

40

5

50

6

60

7

70

8 9

Table 2.1 Segment 1 Data Forearm 1 (Dominant) Force at Raw Int. EMG EMG Peak [CH 3] p-p [CH 40] [CH 1] mean mean

Force at Peak [CH 1] mean

Forearm 2 Raw EMG [CH 3] p-p

Int. EMG [CH 40] mean

80 90 Few students will exceed 30 kg clench force.

Fatigue

B. Complete Table 2.2 using Segment 2 data from each arm. Table 2.2 Segment 2 data Forearm 1 (Dominant) Maximum Clench Force CH 1 value

II.

50% of max clench force calculate

Forearm 2 Time to Fatigue CH 40 T

Maximum Clench Force CH 1 value

50% of max clench force calculate

Time to fatigue CH 40 T

Yes

No

Questions

C. Is the strength of your right arm different than your left arm?

D. Is there a difference in the absolute values of force generated by males and females in your class? Yes

No

What might explain any difference? Force generation is dependent on size (cross-sectional area) of muscle fibers. The size differs with type of training and levels of testosterone. Resistance training of high-intensity quick actions in short bouts contribute to increased synthesis of actin and myosin and more crossbridge formation during contraction. Testosterone affects muscle mass by increasing the number of myosin and actin proteins in muscle fibers.

E. When holding an object, does the number of motor units remain the same?

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DATA REPORT ANSWER GUIDE Are the same motor units used for the duration of holding the object? Yes, number of motor units remains the same. No, different motor units are used in order to delay fatigue in specific motor units.

F. As you fatigue, the force exerted by your muscles decreases. What physiological processes explain the decline in strength? 1) Neuromuscular fatigue in which the motor neuron has reduced availability of acetylcholine thereby reducing the end-plate potential and the number of muscle APs. Generally, the muscle will fatigue prior to neuromuscular fatigue. 2) There may be less ATP available for crossbridge action. Reducing the number of crossbridges reduces the force of the contraction. 3) Lactic acid accumulation interferes with the coupling of muscle AP with contractile processes. 4) The ionic balance for AP propagation may be affected by the relative lack of ATP for the Na+-K+ ATPase pump so that AP propagation is impaired.

G. Define motor unit A motor unit consists of one motor neuron and the muscle fibers that the motor neuron innervates. The motor neuron has many terminals with each terminal ending on a different muscle fiber.

H. Define motor unit recruitment Motor unit recruitment is the activation of increasing numbers of motor units in a muscle to achieve graded levels of contractile strength.

I. Define fatigue Fatigue is a drop in muscle force generation for a given level of stimulation. A definition for muscle fatigue is the physiological inability to contract.

J. Define EMG Electromyography (EMG) is the study of recordings of muscle activity.

K. Define dynamometry Dynamometry is the study of power output of a muscle or group of muscles. Power is defined as work/time; work = force X distance, and the force is due to the levels of muscle contractile activity (or crossbridge formation) End of Lesson 2 Data Report Answer Guide

Lesson 3 I.

ELECTROENCEPHALOGRAPHY I—EEG I

Data and Calculations

A. EEG Amplitude Measurements Complete Table 3.2 with Standard Deviation measurements: Table 3.2 Standard Deviation [stddev] Rhythm

Channel

Alpha

CH 2

Beta

CH 3

Delta

CH 4

Eyes Closed

Eyes Open

Eyes Re-closed

Theta CH 5 The Alpha standard deviation will be higher for eyes closed than eyes open. Beta standard deviation will not change systematically. The amplitude values are generally lower for lab situations than reported in Table 3.1 in the Introduction, repeated here for easy reference:

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Biopac Student Lab Typical Amplitudes of Synchronized Brainwaves Rhythm Typical Amplitude (V) alpha

20-200

beta

5-10

delta

20-200

theta

10

B. EEG Frequency Measurements Complete Table 3.3 with the frequencies for each rhythm and calculate the mean frequency: Table 3.3 Frequency (Hz) Rhythm

Channel

Alpha

CH 2

Beta

CH 3

Delta

CH 4

Cycle 1

Cycle 2

Cycle 3

Mean

Theta CH 5 Frequencies were listed in Table 3.1 in the Introduction, repeated below for reference: Typical Frequencies of Synchronized Brainwaves Rhythm alpha beta delta theta II.

Typical Frequencies (Hz) 8-13 13-30 1-5 4-8

Questions

C. List and define two characteristics of regular, periodic waveforms. 1.

Frequency — number of wave cycles per unit of time.

2.

Amplitude — the height or peak measurement of the cycle as measured from the baseline.

D. Compare and contrast synchrony and alpha block. Synchrony occurs when the positive and negative input to the surface of the cerebral cortex occurs in unison under the recording electrode. Alpha block occurs when the synchronous rhythmical input producing the alpha waves is desychronized (less unison) due to input from other parts of the brain.

E. Examine the alpha and beta waveforms for change between the “eyes closed” state and the “eyes open” state. i.

Does desynchronization of the alpha rhythm occur when the eyes are open? Yes, there is less synchrony (unison of input) being recorded by the electrodes.

ii.

Does the beta rhythm become more pronounced in the “eyes open” state? Yes, the beta rhythm is characteristic of more alert states so there will be a shift in frequency away from the alpha rhythm (so the alpha rhythm will decrease). However, the amplitude of the beta rhythm may not increase when the eyes are open. The amplitude of the rhythms is the sum of the input activity. Because the change in mental activity causes both positive and negative inputs to be generated at the same time, the positive and negative inputs “cancel” each other so that the amplitude recorded by the electrode adds to a lower amplitude.

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DATA REPORT ANSWER GUIDE

F. The amplitude measurements (stddev) are indicative of how much alpha activity is occurring in the subject. But, the amplitude values for beta do not truly reflect the amount of mental activity occurring with the eyes open. Explain. Same as above in D(b). The amplitude recorded by the electrodes is the sum of all the inputs under the electrodes. Because 1 square millimeter of cortical surface can have +100,000 neurons, the individual positive and negative inputs can add to a lower amplitude when there is no synchrony or unison of rhythm.

G. Examine the delta and theta rhythm. Is there an increase in delta and theta activity when the eyes are open? Explain your observation. These rhythms are variable between individuals and depend on their mental states while recording so answers will vary. Students can explain their observations: delta wave amplitudes can increase with attentional processes; Delta and theta rhythms could decrease because of less relaxation; theta wave might increase due to emotional response to sensory input with eyes open.

H. Define the following terms: i.

Alpha rhythm Synchronized brain pattern with frequency of about 8-13 Hz and varying amplitudes, associated with relaxed inattentive state.

ii.

Beta rhythm Brain pattern recorded of alert individual with frequencies of 13-30 Hz, low amplitudes.

iii. Delta rhythm Brain pattern of slow frequencies (1-5 Hz) and variable amplitudes, reliably recorded during certain sleep phases. iv. Theta rhythm Brain pattern of slow frequencies (4-8 Hz) and low amplitudes, reliably recorded during certain sleep phases. End of Lesson 3 Data Report Answer Guide

Lesson 4

ELECTROENCEPHALOGRAPHY II—EEG II

I. DATA AND CALCULATIONS Amplitudes A. Complete Table 4.1 with the amplitudes of the recorded data in the control and experimental conditions. Table 4.1 Segment Condition Raw EEG Alpha Alpha rms [1-Stddev] 1

Eyes Closed (Control)

2

Eyes Closed, performing Mental Math

3

Eyes Closed, recovering from Hyperventilation

4 Frequency

[41-Stddev]

Eyes Open

B. What is the frequency of an alpha rhythm from Segment 1 data?

Hz

[42-Mean]

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Biopac Student Lab Does this agree with the expected values?

Yes

No

Expected frequency values for an alpha rhythm: 8-13 Hz C. Complete Table 4.2 with the mean values of alpha-rms channel from Table 4.1. The “Control Mean” is the mean alpha-rms from data Segment 1. You will need to calculate the difference between the Experimental Mean and the Control Mean. Summarize whether the Experimental Mean was larger (+), smaller (),  or the same (=) as the Control Mean. Table 4.2 Segment 2 3 4

Experimental Condition Performing Mental Math Recovering from Hyperventilate Eyes open

Experimental Mean

Control Mean

Difference (Exp. - Control)

Summary (+, , =)

II. QUESTIONS D. Refer to Table 4.1: When was the general amplitude of the EEG highest? Hyperventilation tends to increase the amplitude of the EEG although the effect will vary with the effectiveness of hyperventilation in changing carbon dioxide and oxygen levels in the blood. E. Refer to Table 4.1: When were the alpha wave levels highest? The alpha wave levels tend to be highest when subjects are relaxed, drowsy, and inattentive. According to recent research results, alpha wave levels increase with changing levels of oxygen and carbon dioxide, as may be induced by hyperventilation. F.

Refer to Table 4.1: How do your results compare with the information presented in the Introduction? Answers will vary.

G. Did Subject need to concentrate during math problems?

Yes

No How would the level of concentration

required affect the data? If the math problems were too difficult, the Subject may just give up trying to answer, and since alpha activity is inversely correlated with attention or concentration, the alpha activity would increase. If the math problems were too easy, the concentration level would be low, which also would result in increased alpha. A decrease in alpha activity will only occur when the Subject is properly challenged by the questions. H. What might account for the amplitude difference of waves recorded from a subject tested alone, in a darkened room, and subjects tested in a lab full of students? Distractions or stimuli that disrupt relaxation levels will affect amplitudes of the alpha wave. Delta and Theta waves also can be changed with stimuli or emotional responses. I. Which conditions produced the lowest alpha activity? Studies show that eyes open or attending to stimuli lowers alpha activity. End of Lesson 4 Report Answer Guide

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DATA REPORT ANSWER GUIDE Lesson 5

ELECTROCARDIOGRAPHY I—ECG I

I.

Data and Calculations Normative values compiled from data in Basic Dysrhythmias: Interpretation and Management, 2e. by Robert J. Huzar, M.D. published by Mosby Lifeline.ISBN 0-8016-7203-1. A. Supine, Resting, Regular Breathing (using Segment 1 data)

Complete the following tables with the lesson data indicated, and calculate the Mean and Range as appropriate. Table 5.2

Measurement T...