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Recitation and Lab # 04 12 The goal of this recitations / labs is to review material related to the

heart for the second test of this course. Info on the heart as a pump has been referred to in lectures and is presented in labs as computer simulations related to the frog model and heart functions (4 expts) and to the ECG and heart function (6 expts). Although no additional info is presented in the lab section, its content allows for a better discussion of the material presented in the lecture / recitation course.

Question and answers related to the heart lecture: •  Ranking of most important items for recitation / lab # 04

–  Name the main four differences between cardiocytes and skeletal muscle cells. Please see figures for lecture on heart as a pump.

–  For each of these 4 differences answer in an “a, b, c, and d” format. Please notice that this question is equivalent to 4 “regular” recitations.

–  In order to answer this recitation question you need to understand all material tested in your first exam plus the material presented in the lecture on the heart as a pump and summarized in the lab # 04.

Recitation question # 04 The fourth recitation question attempted to “force” you to practice on the

(a,b,c,d) sub-questions for four specific characteristics presented in a lecture. "

If you can not write an idea into a single sentence, "you probably have not yet understood the material.

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Recitation question # 04 The fourth recitation question attempted to “force” you to practice on the

(a,b,c,d) sub-questions for four specific characteristics presented in a lecture. "

If you can not write an idea into a single sentence, "you probably have not yet understood the material.

Recitation question # 04 Characteristics of cardiocytes not present in

skeletal muscles

the heart is an electrical syncitium! intercalated disks!

the heart does not tetanize! delay K gate opening due to increase intracellular calcium!

the heart has automaticity! delay K gate opening cause Na leakage to reach threhold!

the heart has a variable force of contraction under extrinsic and intrinsic control!

Na / Ca channels and Ca channels!

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Recitation question # 04 Characteristics of cardiocytes not present in

skeletal muscles!Structure / Function Relationships !

Electrical syncitium! a)  Gap junctions / Intercellular Na diffusion!b)   …….!c)  ……..!d)   ………!

Does not tetanize! a)  L-Type Ca channels / Long absolute refractory period!b)   ………!c)  ……….!d)   ………..!

Automaticity! a)  Funny channels / Automatic depolarization to threshold!b)   ………….!c)  …………!d)   …………. !

Intrinsic control! a)  Stretch receptors / Extra L-Type Ca channels open!b)   ……………!c)  …………..!d)   …………..!

Virtual Lab # 04

Physiology Interactive Lab Simulation (PhILS)

Students should review all simulated experimental labs available in the software package used for this course.

Students should perform the different labs following the instructions and time schedule defined for each lab.

12 The goal of this recitations / labs is to review material related to the heart for the second test of this course. Info on the heart as a pump has been referred to in lectures and is presented in labs as computer simulations related to the frog model and heart functions (4 expts) and to the ECG and heart function (6 expts). Although no additional info is presented in the lab section, its content allows for a better discussion of the material presented in the lecture / recitation course.

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Physiology Interactive Lab Simulations (PhILS version 2.0 has fewer labs than PhILS version 3.0)

Osmosis and diffusion 01 varying ECF concentration

Metabolism

02 size and basal metabolic rate 03 cyanide and electron transfer

Skeletal muscle function

04 stimulus dependent force generation 05 the length - tension relationship 06 principles of summation and tetanus 07 EMG and twitch amplitude

Resting potential

08 resting potential and external K 09 resting potential and external Na

Action potentials

10 the compound action potential 11 conduction velocity and temperature 12 refractory period 13 measuring ion currents

Synaptic potential

14 facilitation and depression 15 temporal summation of EPSPs 16 spatial summation of EPSPs

Endocrine function

17 thyroid gland and metabolic rate

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block

ECG and heart function

22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG

Circulation

28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position

Blood

31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding

Respiration

33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function

Digestion

37 Glucose transport

PhILS - Frog Heart Function (thermal and chemical effects)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Describe steps in exposing the frog heart 2)  Use virtual recording instruments to monitor the movement of

the exposed heart by recording a deflection of a line tracing 3)  Measure the amplitude of the line deflection 4)  Measure time between deflections and convert it into a rate, bpm 5)  Apply cold Ringer, adrenaline, and acetylcholine and monitor the

effects on heart contractions as an indication of stroke volume

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PhILS - Frog Heart Function (thermal and chemical effects)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

PhILS - Frog Heart Function (thermal and chemical effects)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

Cooling and Ach slow heart rate (HR) and decreases cardiac output (CO). Cooling slows the rate at which channels open and close, whereas Ach hyperpolarize the membranes of the pacemaker cells, which slows the rate of depolarization and increases the difference between membrane potential and threshold. Adrenaline (also known as epinephrine or Epi across the Atlantic ocean) increases HR by depolarizing the membrane and increasing the rate of depolarization. In addition, adrenaline is secreted onto the cardiac muscle, which produces stronger contractions and a larger stroke volume (SV). These two factors, a fast HR and increased SV, increase the CO.

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PhILS - Frog Heart Function (refractory period of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Describe steps in exposing the frog heart 2)  Use virtual recording instruments to monitor the movement of

the exposed heart by recording a deflection of a line tracing 3)  Apply brief electrical shocks to the ventricle 4)  Determine when an electrical shock can produce a contraction

during the cardiac cycle 5)  Describe the refractory period in terms of time when a contrac-

tion can not be produced by ventricular electrical stimulation

PhILS - Frog Heart Function (refractory period of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

The cardiac cycle consist of a contraction of the atria followed by a ventricular contraction. In this lab, electrical shocks were applied to the exposed frog heart to produce second contrac-tions of the ventricle. The extra ventricular contractions were produced only when the ventricle was relaxing. These data suggest that there is a prolonged refractory period following the AP, which prevents the ventricle from fibrillation. This feature insures that the muscle has time to relax so that the heart can filled with blood before contracting once more.

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PhILS - Frog Heart Function (Starling’s law of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Describe steps in exposing the frog heart 2)  Use virtual recording instruments to monitor the movement of

the exposed heart by recording a deflection of a line tracing 3)  Measure the amplitude of the line deflection and use it as a

measure of heart contraction 4)  Adjust the length of the heart in a stand and correlate the

amplitude of the line deflection with the length of the heart

PhILS - Frog Heart Function (Starling’s law of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

The amount of tension produced by a contracting heart depends upon the length of the muscle fibers. Stretching the sarcomeres optimizes the amount of overlap between thick and thin filaments with the result that the number of cross-bridges increases. Beyond a certain limit, however, stretching cardiac muscle fibers decreases both filament overlap and tension. Increasing venous return increases end diastolic volume (EDV). Stretched cardiocytes produced more tension and the stronger contraction ejects more blood from the ventricle (Sterling law of the heart).

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PhILS - Frog Heart Function (heart block)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Describe steps in exposing the frog heart 2)  Use virtual recording instruments to monitor the movement of

the exposed heart by recording a deflection of a line tracing 3)  Determine which components of the line tracing are produced by

a contraction of the atria and the ventricle 4)  Interrupt communication through AV node to simulate a block 5)  Observe synchronous beating of the atria and the ventricle

PhILS - Frog Heart Function (heart block)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

atria

ventricle sulcus

control

The heart pacemaker is in the sinoatrial (SA) node and APs are conducted from theree directly to the atria and ventricles through muscle cells that make-up a heart connection system. The cells that conduct APs to the ventricles are also pacemaker cells, but their rhythm is much slower than those in the SA node, and its effect is never seen in the normal heart. In this lab, a thread was tied around the frog heart to prevent communication between the SA node and the conducting system. The atria contracted at its normal rate, but the ventricle showed a slower rate, as it was driven by the AV node (a slower pacemaker).

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PhILS - ECG and Heart Function (ECG and exercise)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instruments to display the ECG on the screen 3)  Identify the different components of the human ECG 4)  Determine HR by measuring time between adjacent R-waves 5)  Measure timefor the P-R, R-T, and T-P segments 6)  Determine which of these three segments account for the

exercise – induced changes in the R-R interval

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

PhILS - ECG and Heart Function (ECG and exercise)

Exercise increase HR, which is seen as a decrease in the time interval between adjacent R waves in the ECG. Exercise does not change the P-R and R-T segments suggesting that the cardiac cycle is not substantially influenced by exercise. However, R-P segments is decreased by a time that is comparable to that seen in the R-R interval. This observation indicates that exercise – induced increases in HR can be accounted for by a decrease in the time interval between cardiac cycles, the time when coronary blood flow occurs.

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PhILS - ECG and Heart Function (the meaning of heart sounds)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instruments to display the ECG on the screen 3)  Use virtual event marker to indicate heart sounds on the screen 4)  Correlate the heart sounds to the different ECG components 5)  Describe how the ECG relates to heart valve function

PhILS - ECG and Heart Function (the meaning of heart sounds)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

Depolarization of the ventricle muscle fibers is a significant com-ponent of the QRS complex of the ECG and initiates contraction. The resulting increase in ventricular blood pressure closes atrio-ventricular valves and produces the “lub” heart sound (up). As a result the “lub” heart sound occurs around the QRS wave. Ventricular repolarization evokes the T-wave and relaxation of the ventricle. The resulting drop in ventricular blood pressure closes semilunar valves and produces the “dup” heart sound (down). The “dup” sound, thus, is heard around the T-wave of the ECG.

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PhILS - ECG and Heart Function (ECG and finger pulse)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instruments to display the ECG and the finger pulse,

on the screen of a virtual computer 3)  Identify the different components of the human ECG 4)  Measure the time interval between the P-wave and the peak of

the finger pulse, and describe the events that take place in the circulatory system

PhILS - ECG and Heart Function (ECG and finger pulse)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

An AP in the ventricles produces a contraction which increases blood pressure and closes the atrioventricular (AV) valves. The contraction continues and when the blood pressure in the left ventricle is greater than that in the aorta, the semilunar valves open, and blood flows from the left ventricle into the aorta. The resulting increase in blood pressure maintains blood flow around the circulatory system. This lab shows that increase in arterial blood pressure is detected in the finger about 0.25 seconds after the AP in the ventricles.

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PhILS - ECG and Heart Function (electrical axis of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instrument to display the ECG on a computer screen 3)  Identify and describe the different components of human ECG 4)  Measure the amplitude of the QRS-wave with the electrodes at

two different orientations 5)  Use the data to calculate the electrical axis of the heart

PhILS - ECG and Heart Function (electrical axis of the heart)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

The heart lies at an angle in the chest with the tip pointing to the left side. This lab measures the amplitude of the QRS complex with the recording electrodes in two orientations. The data are used to construct a graph and draw a line that represents the angle of the heart. The volunteer in this lab had a heart that was about 70 degrees from the horizontal axis.

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PhILS - ECG and Heart Function (ECG and heart block)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instrument to display the ECG on a computer screen 3)  Analyze the ECG from a volunteer with a normal ECG and from

four students with different levels of heart block 4)  Determine the severity of the heart block and explain the

underlying mechanism

PhILS - ECG and Heart Function (ECG and heart block)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

Problems with communication through the AV node can delay or prevent excitation of the ventricles. The degree of heart or AV block is categorize at 3 levels. A 1st degree AV block occurs when the AP moves slowly through the AV node and the P-R interval is greater than 0.2 sec. A 2nd degree block occurs when the P-R interval slowly increases over time until the QRS is skipped. A 3rd degree block occurs when there is no communication through the AV node. Under these conditions atria and ventricle beat independently, and the slower ventricular pacemaker is usually in the AV node, the AV bundle, or the Purkinje fiber.

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PhILS - ECG and Heart Function (abnormal ECG)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

At the completion of this simulation you will be able to: 1)  Connect patch electrodes to the volunteer’s wrist and left ankle 2)  Use virtual instrument to display the ECG on a computer screen 3)  Analyze the ECG from a volunteer with a normal ECG and from

three students with abnormal ECGs 4)  Explain the physiological problems in the hearts of students with

abnormal ECGs

Amy’s ECG is normal but Brian’s QRS-waves have two peaks. This probably indicates a problem in conduction of APs from AV node to ventricle myocardium, and may be due to differences in conduction velocity along the two AV bundles. Chris has an ectopic beat every 3 cycles, indicative of extra beats coming from the AV node, AV bundle, or a Purkinje fiber. Deb has atrial fibrillation, where the atria contract at a very high frequency.

PhILS - ECG and Heart Function (abnormal ECG)

Frog heart function 18 thermal and chemical effects 19 refractory period of the heart 20 Starling’s law of the heart 21 heart block ECG and heart function 22 ECG and exercise 23 the meaning of heart sounds 24 ECG and finger pulse 25 electrical axis of the heart 26 ECG and heart block 27 abnormal ECG Circulation 28 cooling and peripheral blood flow 29 blood pressure and gravity 30 blood pressure and body position Blood 31 pH and Hb - O2 binding 32 DPG and Hb - O2 binding Respiration 33 altering body position 34 altering airway volume 35 exercise - induced changes 36 deep breathing and cardiac function Digestion 37 Glucose transport

Amy Bryan

Chris Deb