Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HOM > Practical Paper > Flashcards

Practical Paper Flashcards

1
Q

The two traces below were recorded over 4 seconds, the top trace with no filter; what filter may have been used to reduce noise on the lower trace?

A

10Hz low pass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the approximate latency between the stimulus and the response in the elctromyogram shown below (the scale on the X axis is in seconds)?

A

10msec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Text BoxPower Lab was used to measure the voltage across the membrane. The left side of the cell (the reference side) was filled with 100 mM KCl, and the test side was filled with 20 mM KCl. The experiment was conducted at 20°C. The voltage recorded in the experiment was actually found to be further from zero than the correct predicted value. What could potentially explain this?

A

The reference solution could have contained a higher concentration of KCl than was believed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The graph above shows the relationship between the action potential amplitude vs the stimulus interval as demonstrated in the earthworm. What is the maximum possible frequency of action potential generation in a short-term experiment?

A

500Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

During exercise the heart rate increases and the duration of systole decreases a little and that of diastole very much more. Which of the following mechanisms account for these changes?
-β1 stimulation shortens the conduction delay in the AV node
-β1 stimulation decreases the activity of the SERCA pump and hence delays Ca2+ re-uptake
-The increased venous return stretches the heart and activates the tension dependent Na+/Ca2+ exchanger
-β1 stimulation of the SAN increases the rate of K+ efflux from the cells
-All of the above

A

All of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

During exercise the heart rate increases and the duration of systole decreases a little and that of diastole very much more. What mechanisms account for these changes?

A

-β1 stimulation shortens the conduction delay in the AV node
-β1 stimulation decreases the activity of the SERCA pump and hence delays Ca2+ re-uptake
-The increased venous return stretches the heart and activates the tension dependent Na+/Ca2+ exchanger
-β1 stimulation of the SAN increases the rate of K+ efflux from the cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the ideal gas equation?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the latent period?

A

The delay from the point of stimulation to the action potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What causes the stimulus artefact?

A

The stimulating current traveling directly to the recording electrodes through the body of the worm, or through any liquid on its surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the relative refractory period?

A

The time period after an action potential during which a higher stimulating voltage is required for a second action potential to be generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the absolute refractory period?

A

The time period following an action potential during which a second action potential cannot be generated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the role of the earth electrode?

A

To reduce noise and the stimulus artefact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where should the earth electrode be placed?

A

Between the stimulating and recording electrodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why should the cathode be closer to the recording electrodes than the anode?

A

Hyperpolarization produced by the anode might prevent the action potential from passing this point on the nerve (“anode block”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which stimulating electrode should be closest to the recording electrodes?

A

Cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is the cathode expected to initiate the action potential?

A

Because a negative electrode placed outside a nerve fibre will reduce the potential difference between the inside and outside of the axon, depolarizing the membrane to the point of threshold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What electrode is expected to initiate the action potential?

A

Cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

In order to initiate an action potential what must happen to the nerve fibre?

A

Must be depolarised

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where are the pins placed in the worm?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Why is the worm is dorsal side up, and pins are placed away from the mid-line?

A

To avoid damaging the ventral nerve cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does a 10Hz high pass filter do?

A

A 10 Hz high-pass filter will remove most of the signal, leaving the high-frequency noise above 10Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does a 10Hz low pass filter do?

A

A 10 Hz low-pass filter removes frequencies above 10Hz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does a 50Hz low pass filter do?

A

A 50 Hz low-pass filter will allow through only those frequency components in your recording below 50 Hz, but this does not usually make very much difference to the trace: it looks very similar to the raw data

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How can the respiratory quotient equation be simplified?

A

RQ= CO2 production/O2 used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How do you calculate the respiratory quotient?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the Fick principal?

A

The rate of blood flow through an organ is equal to the rate of exchange (i.e. gain or loss) of a particular substance (z) from that organ, divided by the difference in concentration of that substance in the blood entering (x) and leaving (y) the organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does STPD stand for?

A

Standard Temperature and Pressure, Dry

28
Q

What does ATPS stand for?

A

Atmospheric Temperature and Pressure, Saturated

29
Q

How do you use the Fick principal to calculate cardiac output?

A
30
Q

How do you find the alveolar partial pressure for any gas that you know the dry percentage of?

A
31
Q
A

VA = alveolar ventilation rate
VECO2 = rate of CO2 production
PACO2 = alveolar partial pressure of CO2
K = conversion constant

32
Q

What is the alveolar ventilation equation?

A
33
Q

What is a more accurate way of calculating max pulse rate?

A

208 - (0.7 x your age in years)

34
Q

How do you calculate max pulse rate?

A

220-(your age in years)

35
Q

Cardiac output =

A

Stroke volume x Heart rate

36
Q

Power =

A

Force x Velocity

37
Q

Work =

A

Force x Distance

38
Q

How do you calculate pulse pressure?

A

Systolic - Diastolic

39
Q

How do you calculate mean arterial blood pressure?

A

MAP = Diastolic + 1/3pulse pressure

40
Q

What is a more accurate method for determining conduction velocity?

A

Compare equivalent action potential peaks on two traces, obtained when recording at two different distances (D1 and D2) from the stimulating electrodes.

41
Q

To calculate conduction velocity by the “difference method” what equation do you use?

A

Conduction velocity = (D2 - D1) / (LP2 - LP1)

42
Q

How do you calculate the conduction velocity?

A

D/LP

D=distance(mm)
LP=latent period(ms)

43
Q

What is the time constant (τ) equal to?

A

τ=RC

time constant = resistance x capacitance
The time at which the voltage has reached 63% of its original value

44
Q

What is τ?

A

Time constant

45
Q

If we were to measure the voltage while the capacitor is charging, we would find a relationship given by the equation:

A
46
Q

How do you avoid aliasing?

A

By setting the sampling rate to greater than twice the frequency of the original signal

47
Q

Current =

A

Voltage x Resistance

48
Q

Conductance =

A

1/Resistance = Current/Voltage

49
Q

What are the assumptions of the Nernst equations?

A

Only one ion permeable
Membrane completely permeable to that ion
Ion at equilibrium

50
Q

What is the Nernst equation?

A
51
Q

What is E?

A

Nernst equilibrium potential

52
Q

What is R?

A

Ideal gas constant

53
Q

What is T?

A

Temperature (kelvin)

54
Q

What is z?

A

Charge of ion (ie 1, 2, 3)

55
Q

What is F?

A

Faraday’s number

56
Q

What is ln?

A

Natural log

57
Q

What is [C]?

A

Concentration of ion

58
Q

What is the Nernst equation simplified to at room temperature (20 degrees)?

A

E = 58/z x log10([Cref]/[Ctest])

59
Q

How do you alter the Nernst equation for a monovalent anion?

A

Invert [C] in/out and z=1

60
Q

What is the Nernst equation for a cation at body temperature (37 degrees)?

A

E = 61/z x log10([Cout]/[Cin])

61
Q

What is the Nernst equation for an anion at body temperature (37 degrees)?

A

E = 61/z x log10([Cin]/[Cout])

62
Q

What is the equilibrium potential of sodium at body temperature?

A

+61mV

63
Q

What is the equilibrium potential of calcium at body temperature?

A

+120mV

64
Q

What is the equilibrium potential of potassium at body temperature?

A

-88mV

65
Q

What is the length constant?

A

Distance over which voltage decays to 37% of initial value

HOM (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions