Download Worksheets - Wesleyan College Faculty

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BIOLOGY 340 - WORKSHEET FOR LAB 1
Electrophysiology Instrumentation
1. WHAT IS THE MEANING OF BOLD, UNDERLINED, CAPITALIZED TYPE LIKE THIS IN THE
LABORATORY MANUAL?
2. For what kinds of signals would a physiograph (or the Chart application) be more appropriate
and useful than an oscilloscope (or the Scope application)?
3. For what kinds of signals would an oscilloscope (or the Scope application) be more
appropriate and useful than a physiograph (or the Chart application)?
4. On an oscilloscope, a chart recorder, a Scope display, or a Chart display, what is represented
on the X-axis?
What is represented on the Y-axis?
5. In Section I Part C (p 5) what is the main source of the sinusoidal noise?
What is the dominant frequency of this noise in the United States?
6. On the electronic stimulator, what is the difference between "DELAY" and
"DURATION"?
7. If you are recording a repeating square wave signal using the Chart application, what happens
to your recorded trace on the screen if you sample at too low a frequency?
8. In the Scope application, what is the difference between Sampling with Mode:Repetitive and
the Mode:Multiple choices under the Set-Up menu?
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BIOLOGY 340 - WORKSHEET FOR LAB 2
Permeability of the Red Blood Cell Membrane
1. What will happen to the volume of an RBC if the RBC is placed in a hyperosmotic solution
of an impermeant solute?
2. How will the transmittance of a suspension of RBCs at 600nm change as hemolysis
proceeds?
3. Why will we use a wavelength of 600nm for our spectrophotometry?
4. What effect should each of the following have on the ability of a solute to cause hemolysis?
a. Increasing the oil-water partition coefficient of the solute.
b. Increasing the number of polar groups (e.g. -OH) in the solute.
c. Increasing the molecular weight of the solute.
5. Define hematocrit.
6. Which MacLab program will we use to monitor hemolysis?
7. Why is it important to stir the RBC suspension immediately before each aliquot is removed?
8. V / V0 = [C0 - (bC0 / V0 )] (1 / C) + b / V0 is the equation for a line. If we plot V / V0 on the y
axis and (1 / C) on the x axis:
a. What is the slope of this line?
b. What is the y-intercept of this line?
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BIOLOGY 340 - WORKSHEET FOR LAB 3
Active Transport in the Frog Skin
1. What is the primary cation which is actively transported across the frog skin?
Which surface of the frog skin is more permeable to this cation, the inner or the outer?
2. What drives the flow of chloride "passively" across the skin?
3. Why is a "short-circuit" current necessary to quantify the rate of active transport across the
frog skin?
What units of measurement will you use to quantify current?
4. Why must the fluid levels be equal on the two sides of the frog skin to accurately measure
potentials or currents?
5. Why must air be periodically bubbled through the solutions in both compartments?
6. How will we test the ionic specificity of the active transport "pump" in this laboratory?
7. By what mechanism does ouabain depolarize heart cells?
8. What MacLab program will we be using to monitor electrical potential?
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BIOLOGY 340 - WORKSHEET FOR LAB 4
Compound Action Potentials in the Frog Sciatic Nerve
1. In what part of the frog is the sciatic nerve located?
2. Why is it important that the nerve not touch the outside of the frog's skin?
3. Which MacLab program will you use to record from the sciatic nerve?
4. Why are the impulses that you will record from the sciatic nerve called "compound" action
potentials?
5. Which one of the two refractory periods immediately follows the action potential?
6. How will you alter the nerve in order to record monophasically?
7. Label each peak in the monophasic nerve recording shown below.
Indicate which peak corresponds to the largest diameter axons.
Indicate which peak corresponds to the axons with the highest conduction velocity.
8. Define rheobase.
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BIOLOGY 340 - WORKSHEET FOR LAB 5
Sensory Coding by APs in the Cockroach Leg
1. What is a “mechanoreceptor”?
2. What exactly is a “tactile sensillum” and where on the cockroach would you likely find one?
3. What will serve as your electrodes in this lab?
4. What is the purpose of the 100Hz and 5kHz amplifier filters – i.e. what are you filtering out?
5. What is the purpose of using a micromanipulator to deflect the tibial spines?
6. What defines a purely “tonic” response pattern?
7. What information about the stimulus level would a tonic response pattern convey to the
roach?
8. What defines a purely “phasic” response pattern?
9. What information about the stimulus level would a phasic response pattern convey to the
roach?
10. What does the campaniform organ measure or monitor for the roach?
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BIOLOGY 340 - WORKSHEET FOR LAB 6
Excitation and Contraction of Frog Skeletal Muscle
1. What will you stimulate to initiate muscle contractions?
2. Define spatial summation in a muscle.
3. Define temporal summation in a muscle.
4. Which MacLab program will you be using to record muscle contractions?
5. Since MacLab records only voltages, how can you use it to record muscle contractions (i.e.
changes in muscle length)?
6. What is the difference between an isometric and an isotonic contraction?
Which kind of contraction (isometric or isotonic) will you be recording?
7. Define tetanus.
8. In the graph below, draw the two curves you would expect to see if you plotted distance of
shortening and work as a function of load for an isotonically contracting muscle. Be sure to
label each curve.
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BIOLOGY 340 - WORKSHEET FOR LAB 7
Control of Microvascular Circulation in the Frog Tongue
1. In previous labs we have sacrificed frogs by decapitating them. Why are the frogs for this
experiment pithed instead?
2. What is the purpose of the observation hole in the frog board?
3. What is the mathematical relationship between the radius of a rigid tube and flow rate
through the tube? In other words, specifically how would you expect the flow rate to change
as you change the radius, while keeping all other relevant variables constant?
4. What are simple treatments you could apply to the frog to increase the blood flow in the
tongue (assuming that the vascular system is intact and functioning)?
5-8.What effect should you expect each of the following to have on capillary blood flow:
lactic acid
epinephrine
ACh
histamine
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BIOLOGY 340 - WORKSHEET FOR LAB 8
Control of Heartbeat in the Frog
1. How many chambers does a frog heart have (not including the sinus venosus) and what are
they?
2. To which part(s) of the frog heart will you attach a transducer clip/hook in this experiment?
3. Why does the sinus node "set the pace" for the heartbeat?
4. What part of the heart contracts last during each cardiac cycle?
5. What is meant by a "myogenic rhythm"?
6. What PowerLab program will you be using to monitor heartbeats.
7. What will you be stimulating to produce partial and complete inhibition of the heartbeat?
8. When the heartbeat is completely inhibited, what will you stimulate to determine the
refractory period?
About how long do you expect the refractory period of this part of the heart to last?
9. How will you generate an extraventricular systole?
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BIOLOGY 340 - WORKSHEET FOR LAB 9
Dietary Control of Blood and Urinary Glucose in Humans
1. What is the approximate glucose concentration in the blood of a typical human following an
overnight fast?
2. Which hormone acts primarily to effectively reduce the concentration of glucose in the
blood?
3. What is glycosuria?
What is reactive hypoglycemia?
4. Why should you empty your bladder one half hour before you come to lab?
What type of food should you consume between the time you finish breakfast and the end of
the lab period?
5. What should you do if your initial blood glucose level is greater than 120mg/dl?
6. In what room will you expose the Keto-Diastix test strips to urine?
7. What should you do with lancets that have been exposed to blood?
8.
What MacLab program will you be using to monitor blood glucose levels in this lab?
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BIOLOGY 340 - WORKSHEET FOR LAB 10
Physiological Reflexes and Responses in Humans
1. What cardiac event produces the "lubb" sound of each heart beat?
What cardiac event produces the "dupp" sound?
2. With the ausculatory method of measuring blood pressure, why are there no Korotkov sounds
when the cuff pressure is higher than arterial systolic pressure?
Why are there no Korotkov sounds when the cuff pressure is lower than arterial diastolic
pressure?
3. Define respiratory tidal volume in common English (no equations please).
4. How could you calculate the pulse velocity in the brachial arterial system, given simultaneous
recordings of the EKG and finger pulse pressure?
5. What is the "heart axis"?
6. What is the function of the vestibulo-oculomotor reflex in moment-to-moment life?
7. What are the defining characteristics of alpha waves?
8. If you are recording the EEG of a subject and it is dominated by alpha activity, what is one
thing you could do to replace the alpha with beta activity?
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